Compounds and Synthesis Methods

Abstract

The present invention provides a novel compound and a synthesis method. In particular, the present invention provides a novel compound and a synthesis method that can improve the device characteristics of a light-emitting device. The present invention is a compound represented by the following formula:

Description

[0001] This application is a divisional application of the Chinese patent application with international application number PCT / IB2016 / 056067 and international application date 2016 / 10 / 11, and national application number 201680061311.6, titled “Heterocyclic compounds, light-emitting elements, light-emitting devices, electronic devices, and lighting devices” after the PCT international application with international application number PCT / IB2016 / 056067 entered the Chinese stage. Technical Field

[0002] One embodiment of the present invention relates to an object, a method and a manufacturing method. In addition, the present invention relates to a process, a machine, a product or a composition of matter. In particular, one embodiment of the present invention relates to a semiconductor device, a light-emitting device, a display device, a lighting device, a light-emitting element or a method for manufacturing the same. In addition, one embodiment of the present invention relates to a heterocyclic compound and a novel method for synthesizing the heterocyclic compound. In addition, one embodiment of the present invention relates to a light-emitting element, a light-emitting device, an electronic device and a lighting device using the above-mentioned heterocyclic compound. Note that one embodiment of the present invention is not limited to the above-mentioned technical field. Background Art

[0003] Light-emitting elements using organic compounds as light-emitting bodies, which have the characteristics of being thin and light, high-speed responsiveness, and DC low-voltage drive, are expected to be applied to the next generation of flat panel displays. In particular, display devices in which light-emitting elements are arranged in a matrix are believed to have the advantages of a wide viewing angle and excellent visibility compared to existing liquid crystal display devices.

[0004] The light emission mechanism of a light emitting element is considered to be as follows: by sandwiching an EL layer containing a light emitting body between a pair of electrodes and applying a voltage to the pair of electrodes, electrons injected from the cathode and holes injected from the anode recombine at the light emission center of the EL layer to form molecular excitons, and when the molecular excitons return to the ground state, energy is released to emit light. It is known that there are singlet excited states and triplet excited states, and it is considered that light emission can be achieved by passing through either of the above excited states.

[0005] In such a light-emitting element, an organic compound is mainly used in the EL layer, which has a great influence on improving the device characteristics of the light-emitting element. Therefore, various novel organic compounds have been developed (for example, refer to Patent Document 1).

[0006] [References]

[0007] [Patent Document]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2007-189001 Summary of the invention

[0009] The compound having a dibenzo[f,h]quinoxaline ring reported in the above-mentioned Patent Document 1 is useful as a material for a light-emitting element. However, there is a demand for a compound having a structure with higher thermal stability. In particular, when considering a vehicle-mounted light-emitting element, a light-emitting device using the light-emitting element, an electronic device, and a lighting device, the heat-resistant temperature of the light-emitting element is preferably above 100°C, so it is an important issue to realize a light-emitting element with high heat resistance. A feasible solution is to use a compound with an increased molecular weight, but the refractive index of the compound that increases the molecular weight only by changing the substituent, etc., also increases. When the compound is used in the EL layer of the light-emitting element, the light extraction efficiency is reduced, which leads to a reduction in the external quantum efficiency of the light-emitting element. In addition, when the heat resistance is increased by increasing the molecular weight, thermal decomposition occurs during deposition by evaporation or sublimation purification, and the film purity may be reduced. Therefore, it is difficult to simultaneously realize a compound having a higher stability than the compound described in Patent Document 1 and an element containing a compound having improved characteristics by simply increasing the molecular weight of the compound.

[0010] Therefore, one of the purposes of one embodiment of the present invention is to provide a novel heterocyclic compound. In particular, one of the purposes of one embodiment of the present invention is to provide a novel heterocyclic compound that can improve the element characteristics of a light-emitting element. One of the purposes of one embodiment of the present invention is to provide a novel light-emitting element with high luminous efficiency and heat resistance. One of the purposes of one embodiment of the present invention is to provide a novel heterocyclic compound that can be used for a light-emitting element. One of the purposes of one embodiment of the present invention is to provide a novel heterocyclic compound that can be used for an EL layer of a light-emitting element. One of the purposes of one embodiment of the present invention is to provide a novel light-emitting element. One of the purposes of one embodiment of the present invention is to provide a novel light-emitting device, a novel electronic device, or a novel lighting device. Note that the description of the above-mentioned purpose does not prevent the existence of other purposes. One embodiment of the present invention does not need to achieve all of the above-mentioned purposes. Purposes other than the above-mentioned purpose are obvious from the description of the specification, drawings, claims, etc., and purposes other than the above-mentioned purpose can be extracted from the description.

[0011] One embodiment of the present invention is a heterocyclic compound represented by the general formula (G1).

[0012] [Chemical formula 1]

[0013]

[0014] In the general formula, A represents any one of a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted dibenzofuranyl group, and a substituted or unsubstituted carbazolyl group. DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. In addition, n is 0 or 1. Ar 1To Ar 4 Each independently represents a substituted or unsubstituted arylene group having 6 to 10 carbon atoms. 1 To Ar 4 Adjacent arylene groups in Ar may also be bonded to each other to form a ring. 1 To Ar 4 When the adjacent arylene groups in form a fluorene skeleton, the fluorene skeleton may have a substituent.

[0015] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G2-1).

[0016] [Chemical formula 2]

[0017]

[0018] In the general formula, R 18 To R 20 Any one of them represents a substituent represented by the general formula (G2-2). 18 To R 20 The other two, R 11 To R 17 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0019] [Chemical formula 3]

[0020]

[0021] In the general formula, A represents any one of a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted dibenzofuranyl group, and a substituted or unsubstituted carbazolyl group. In addition, n is 0 or 1. Ar 1 To Ar 4 Each independently represents a substituted or unsubstituted arylene group having 6 to 10 carbon atoms. 1 To Ar 4 Adjacent arylene groups in Ar may also be bonded to each other to form a ring. 1 To Ar 4 When the adjacent arylene groups in form a fluorene skeleton, the fluorene skeleton may have a substituent.

[0022] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G3-1).

[0023] [Chemical formula 4]

[0024]

[0025] In the general formula, R 27 and R 28Any one of them represents a substituent represented by the general formula (G3-2). 27 and R 28 Another one in R 21 To R 26 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. Z represents oxygen, sulfur, or nitrogen. When Z represents nitrogen, the substituent may or may not be bonded to the Z position.

[0026] [Chemical formula 5]

[0027]

[0028] In the general formula, DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. In addition, n is 0 or 1. Ar 1 To Ar 4 Each independently represents a substituted or unsubstituted arylene group having 6 to 10 carbon atoms. 1 To Ar 4 Adjacent arylene groups in Ar may also be bonded to each other to form a ring. 1 To Ar 4 When the adjacent arylene groups in form a fluorene skeleton, the fluorene skeleton may have a substituent.

[0029] In this specification, with respect to the skeleton represented by the general formula (G3-1), when Z represents oxygen, the skeleton is referred to as a dibenzofuran skeleton or a dibenzofuran group, when Z represents sulfur, the skeleton is referred to as a dibenzothiophene skeleton or a dibenzothiophene group, and when Z represents nitrogen, the skeleton is referred to as a carbazole skeleton or a carbazole group.

[0030] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G4-1).

[0031] [Chemical formula 6]

[0032]

[0033] In the general formula, R 31 , R 33 and R 34 Any one of them represents a substituent represented by the general formula (G4-2). 31 , R 33 and R 34 The substituent represented by the general formula (G4-2) is not bonded to the other two, R 32 , R 35 To R 39 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0034] [Chemical formula 7]

[0035]

[0036] In the general formula, DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. In addition, n is 0 or 1. Ar 1 To Ar 4 Each independently represents a substituted or unsubstituted arylene group having 6 to 10 carbon atoms. 1 To Ar 4 Adjacent arylene groups in Ar may also be bonded to each other to form a ring. 1 To Ar 4 When the adjacent arylene groups in form a fluorene skeleton, the fluorene skeleton may have a substituent.

[0037] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G5-1).

[0038] [Chemical formula 8]

[0039]

[0040] In the general formula, R 27 and R 28 Any one of them represents a substituent represented by the general formula (G5-2). 27 and R 28 Another one in R 21 To R 26 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. Z represents oxygen, sulfur or nitrogen. When Z represents nitrogen, the substituent may or may not be bonded to the Z position.

[0041] [Chemical formula 9]

[0042]

[0043] In the general formula, R 11 To R 19 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. In addition, n is 0 or 1. Ar 1 ,Ar 2 ,Ar 3 and Ar 4 Each independently represents a substituted or unsubstituted arylene group having 6 to 10 carbon atoms. 1 To Ar 4 Adjacent arylene groups in Ar may also be bonded to each other to form a ring. 1To Ar 4 When the adjacent arylene groups in form a fluorene skeleton, the fluorene skeleton may have a substituent.

[0044] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-1).

[0045] [Chemical formula 10]

[0046]

[0047] In the general formula, DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. Z represents oxygen or sulfur. 21 To R 27 , R 41 To R 44 , R 51 To R 54 and R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0048] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-1), wherein the substitution position of DBq is the meta position.

[0049] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-1), wherein the substitution position of DBq is the meta position and the substitution position of the dibenzothienyl group or the dibenzofuranyl group is the para position.

[0050] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-2).

[0051] [Chemical formula 11]

[0052]

[0053] In the general formula, DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. Z represents oxygen or sulfur. 21 To R 27 , R 41 To R 44 , R 51 To R 54 and R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0054] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-3).

[0055] [Chemical formula 12]

[0056]

[0057] In the general formula, DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. 32 To R 39 , R 41 To R 44 , R 51 To R 54 and R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0058] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-3), wherein the substitution position of DBq is the meta position.

[0059] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-3), wherein the substitution position of DBq is the meta position and the substitution position of the carbazole group is the para position.

[0060] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-4).

[0061] [Chemical formula 13]

[0062]

[0063] In the general formula, DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. 32 To R 39 , R 41 To R 44 , R 51 To R 54 and R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0064] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-5).

[0065] [Chemical formula 14]

[0066]

[0067] In the general formula, DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. 31 represents an alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.32 To R 36 , R 38 , R 39 , R 41 To R 44 , R 51 To R 54 and R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0068] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-5), wherein the substitution position of DBq is the meta position.

[0069] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-5), wherein the substitution position of DBq is the meta position and the substitution position of the carbazole group is the para position.

[0070] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-6).

[0071] [Chemical formula 15]

[0072]

[0073] In the general formula, DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. 31 represents an alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. 32 To R 36 , R 38 , R 39 , R 41 To R 44 , R 51 To R 54 and R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0074] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-7).

[0075] [Chemical formula 16]

[0076]

[0077] In the general formula, DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. 31 represents an alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.32 To R 37 , R 39 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0078] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-7), wherein the substitution position of DBq is the meta position.

[0079] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-7), wherein the substitution position of DBq is the meta position and the substitution position of the carbazole group is the para position.

[0080] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-8).

[0081] [Chemical formula 17]

[0082]

[0083] In the general formula, DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. 31 represents an alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. 32 To R 37 , R 39 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0084] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G7-1).

[0085] [Chemical formula 18]

[0086]

[0087] In the general formula, A represents any one of a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted dibenzofuranyl group, and a substituted or unsubstituted carbazolyl group. 11 To R 19 , R 41 To R 44 , R51 To R 54 , R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0088] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G7-1), wherein the substitution position of DBq is the meta position.

[0089] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G7-1), wherein the substitution position of DBq is the meta position and the substitution position of A is the para position.

[0090] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G7-2).

[0091] [Chemical formula 19]

[0092]

[0093] In the general formula, A represents any one of a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted dibenzofuranyl group, and a substituted or unsubstituted carbazolyl group. 11 To R 19 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0094] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-1).

[0095] [Chemical formula 20]

[0096]

[0097] In the general formula, Z represents oxygen or sulfur. 11 To R 19 , R 21 To R 27 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0098] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-1), wherein the substitution position of DBq is the meta position.

[0099] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-1), wherein the substitution position of DBq is the meta position and the substitution position of the dibenzothienyl group or the dibenzofuranyl group is the para position.

[0100] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-2).

[0101] [Chemical formula 21]

[0102]

[0103] In the general formula, Z represents oxygen or sulfur. 11 To R 19 , R 21 To R 27 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0104] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-3).

[0105] [Chemical formula 22]

[0106]

[0107] In the general formula, R 11 To R 19 , R 32 To R 39 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0108] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-3), wherein the substitution position of DBq is the meta position.

[0109] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-3), wherein the substitution position of DBq is the meta position and the substitution position of the carbazole group is the para position.

[0110] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-4).

[0111] [Chemical formula 23]

[0112]

[0113] In the general formula, R 11 To R 19 , R 32 To R 39 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0114] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-5).

[0115] [Chemical formula 24]

[0116]

[0117] In the general formula, R 11 To R 19 , R 32 To R 36 , R 38 , R 39 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 R each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. 31 It represents an alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0118] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-5), wherein the substitution position of DBq is the meta position.

[0119] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-5), wherein the substitution position of DBq is the meta position and the substitution position of the carbazole group is the para position.

[0120] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-6).

[0121] [Chemical formula 25]

[0122]

[0123] In the general formula, R 11 To R 19 , R 32 To R 36 , R 38 , R 39 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 R each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. 31 It represents an alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0124] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-7).

[0125] [Chemical formula 26]

[0126]

[0127] In the general formula, R 11 To R 19 , R 32 To R 37 , R 39 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 R each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. 31 It represents an alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0128] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-7), wherein the substitution position of DBq is the meta position.

[0129] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-7), wherein the substitution position of DBq is the meta position and the substitution position of the carbazole group is the para position.

[0130] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-8).

[0131] [Chemical formula 27]

[0132]

[0133] In the general formula, R 11 To R 19 , R 32 To R 37 , R 39 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 R each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. 31 It represents an alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0134] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G9-1).

[0135] [Chemical formula 28]

[0136]

[0137] In the general formula, Z represents oxygen or sulfur.

[0138] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G9-2).

[0139] [Chemical formula 29]

[0140]

[0141] In the general formula, Z represents oxygen or sulfur.

[0142] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G9-3).

[0143] [Chemical formula 30]

[0144]

[0145] In the general formula, Z represents oxygen or sulfur.

[0146] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G9-4).

[0147] [Chemical formula 31]

[0148]

[0149] In the general formula, Z represents oxygen or sulfur.

[0150] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G9-5).

[0151] [Chemical formula 32]

[0152]

[0153] In the general formula, Z represents oxygen or sulfur.

[0154] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G10-1).

[0155] [Chemical formula 33]

[0156]

[0157] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G10-2).

[0158] [Chemical formula 34]

[0159]

[0160] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G10-3).

[0161] [Chemical formula 35]

[0162]

[0163] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G10-4).

[0164] [Chemical formula 36]

[0165]

[0166] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G10-5).

[0167] [Chemical formula 37]

[0168]

[0169] Another embodiment of the present invention is a light-emitting element comprising a compound in which a dibenzo[f,h]quinoxaline ring and a hole-transport skeleton are bonded via a terphenylene group.

[0170] Another embodiment of the present invention is a light-emitting device including, in a light-emitting layer, a light-emitting material and a compound in which a dibenzo[f,h]quinoxaline ring and a hole-transporting skeleton are bonded via a terphenylene group.

[0171] In the light-emitting element according to another embodiment of the present invention, the hole-transport skeleton may include a π-electron-rich heteroaromatic ring.

[0172] In the light-emitting element according to another embodiment of the present invention, the π-electron-rich heteroaromatic ring may be a carbazole ring, a dibenzofuran ring, or a dibenzothiophene ring.

[0173] Another embodiment of the present invention is a light-emitting element including the heterocyclic compound of one embodiment of the present invention and an electrode.

[0174] Another embodiment of the present invention is a light-emitting element including a light-emitting substance and the heterocyclic compound of one embodiment of the present invention in a light-emitting layer.

[0175] Another embodiment of the present invention is a light-emitting device including a light-emitting portion including the light-emitting element according to one embodiment of the present invention, and a substrate.

[0176] Another embodiment of the present invention is an electronic device including a display portion including the light-emitting device of one embodiment of the present invention, and an antenna, a battery, a housing, a speaker, a microphone, or an operation key.

[0177] Another embodiment of the present invention is a lighting device including the light emitting device of one embodiment of the present invention, a housing, a connecting terminal, or a protective cover.

[0178] One embodiment of the present invention can provide a novel heterocyclic compound. In particular, one embodiment of the present invention can provide a novel heterocyclic compound that can improve the element characteristics of a light-emitting element. One embodiment of the present invention can provide a light-emitting element with high luminous efficiency and heat resistance. One embodiment of the present invention can provide a novel heterocyclic compound that can be used for a light-emitting element. One embodiment of the present invention can provide a novel heterocyclic compound that can be used for an EL layer of a light-emitting element. One embodiment of the present invention can provide a novel light-emitting element. One embodiment of the present invention can provide a novel light-emitting device, a novel electronic device, or a novel lighting device.

[0179] Note that the description of these effects does not prevent the existence of other effects. One mode of the present invention does not need to have all of the above effects. Effects other than the above are obvious from the description of the specification, drawings, claims, etc., and effects other than the above can be extracted from the description of the specification, drawings, claims, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0180] Figure 1A and Figure 1B is a schematic diagram of a light emitting element;

[0181] Figure 2A and Figure 2B is a schematic diagram of an active matrix light emitting device;

[0182] Figure 3A and Figure 3B is a schematic diagram of an active matrix light emitting device;

[0183] Figure 4 is a schematic diagram of an active matrix light emitting device;

[0184] Figure 5A and Figure 5B is a schematic diagram of a passive matrix light emitting device;

[0185] FIG. 6A to FIG. 6D is a diagram showing an electronic device;

[0186] Figure 7 is a diagram showing a light source device;

[0187] Figure 8 is a diagram showing a lighting device;

[0188] Fig. 9 is a diagram showing a lighting device and an electronic device;

[0189] Fig.10 is a diagram showing a vehicle-mounted display device and a lighting device;

[0190] Fig.11A and Fig. 11B is the NMR spectrum of 2mDBtTPDBq-II;

[0191] Fig.12 is the absorption spectrum of the solution of 2mDBtTPDBq-II;

[0192] Fig.13 is the emission spectrum of the solution of 2mDBtTPDBq-II;

[0193] Fig.14 is the absorption spectrum of the thin film of 2mDBtTPDBq-II;

[0194] Fig.15 is the emission spectrum of the thin film of 2mDBtTPDBq-II;

[0195] Fig.16 is the phosphorescence spectrum of 2mDBtTPDBq-II;

[0196] Fig.17A and Fig. 17B is the NMR spectrum of 2DBtTPDBq;

[0197] Fig.18 is the absorption spectrum of the solution of 2DBtTPDBq;

[0198] Fig.19is the emission spectrum of the solution of 2DBtTPDBq;

[0199] Fig. 20 is the absorption spectrum of the thin film of 2DBtTPDBq;

[0200] Fig.21 is the emission spectrum of the thin film of 2DBtTPDBq;

[0201] Fig. 22 is the phosphorescence spectrum of 2DBtTPDBq;

[0202] Fig.23A and Fig. 23B is the NMR spectrum of 2DBtTPDBq-03;

[0203] Fig.24 is the absorption spectrum of the solution of 2DBtTPDBq-03;

[0204] Fig.25 is the emission spectrum of the solution of 2DBtTPDBq-03;

[0205] Fig.26 is the absorption spectrum of the thin film of 2DBtTPDBq-03;

[0206] Fig. 27 is the emission spectrum of the thin film of 2DBtTPDBq-03;

[0207] Fig.28 is the phosphorescence spectrum of 2DBtTPDBq-03;

[0208] Fig.29A and Fig.29B is the NMR spectrum of 2DBtTPDBq-02;

[0209] Fig.30 is the absorption spectrum of the solution of 2DBtTPDBq-02;

[0210] Fig.31 is the emission spectrum of the solution of 2DBtTPDBq-02;

[0211] Fig.32 is the absorption spectrum of the thin film of 2DBtTPDBq-02;

[0212] Fig.33 is the emission spectrum of the thin film of 2DBtTPDBq-02;

[0213] Fig.34 is the phosphorescence spectrum of 2DBtTPDBq-02;

[0214] Fig.35A and Fig.35Bis the NMR spectrum of 2DBtTPDBq-04;

[0215] Fig.36 is the absorption spectrum of the solution of 2DBtTPDBq-04;

[0216] Fig.37 is the emission spectrum of the solution of 2DBtTPDBq-04;

[0217] Fig.38 is the absorption spectrum of the thin film of 2DBtTPDBq-04;

[0218] Fig.39 is the emission spectrum of the thin film of 2DBtTPDBq-04;

[0219] Fig.40 is the phosphorescence spectrum of 2DBtTPDBq-04;

[0220] Fig.41A and Fig.41B is the NMR spectrum of 2mDBtQPDBq-II;

[0221] Fig.42 is the absorption spectrum of the thin film of 2mDBtQPDBq-II;

[0222] Fig.43 is the emission spectrum of the thin film of 2mDBtQPDBq-II;

[0223] Fig.44 is the phosphorescence spectrum of 2mDBtQPDBq-II;

[0224] Fig.45A and Fig.45B is the NMR spectrum of 3-(3'-chloro-1,1'-biphenyl-4-yl)-9-phenyl-9H-carbazole;

[0225] Fig.46A and Fig.46B is the NMR spectrum of 2mmpPCTPDBq;

[0226] Fig.47 is the absorption spectrum of a solution of 2 mm pPCTPDBq;

[0227] Fig.48 is the emission spectrum of a solution of 2 mm pPCTPDBq;

[0228] Fig.49 is the absorption spectrum of the film of 2 mmpPCTPDBq;

[0229] Fig.50 is the emission spectrum of the film of 2 mmpPCTPDBq;

[0230] Fig.51 is the phosphorescence spectrum of 2mmpPCTPDBq;

[0231] Fig.52A and Fig.52B is the NMR spectrum of 2mPCBPDBq;

[0232] Fig.53 is a diagram showing the reliability test results of Light Emitting Elements 1 to 6 and Comparative Light Emitting Element 8;

[0233] Fig.54 is a diagram showing the reliability test results of the light emitting element 9 and the comparative light emitting element 10;

[0234] Fig.55 It is a graph showing the results of evaluating the thermal properties of the light-emitting element. DETAILED DESCRIPTION

[0235] The following describes the embodiments of the present invention. However, those skilled in the art can easily understand that the methods and details disclosed herein can be transformed into various forms without departing from the purpose and scope of the present invention. Therefore, the present invention should not be interpreted as being limited to the contents described in the following embodiments.

[0236] In addition, in each of the drawings described in this specification, the size and thickness of the components such as the anode, EL layer, intermediate layer, cathode, etc. are sometimes exaggerated for the sake of convenience. Therefore, the size of each component is not limited to the size shown in the drawings and the relative size between the components.

[0237] In this specification, etc., for the sake of convenience, ordinal numbers such as first, second, and third are added, but they do not indicate the order of processes or the order of stacking. Therefore, for example, even if "first" is appropriately replaced with "second" or "third", etc., the description can be made. In addition, the ordinal numbers recorded in this specification, etc. may not be consistent with the ordinal numbers used to specify one embodiment of the present invention.

[0238] In the configuration of the present invention described in this specification, the same symbol is used in common between different drawings to represent the same part or the part with the same function without repeating the description of these parts. In addition, sometimes the same hatching is used for the part with the same function without adding a special figure mark to represent the part.

[0239] In this specification, color is defined by three elements: hue (equivalent to the wavelength of monochromatic light), chromaticity (chroma, i.e., the degree of difference from white) and lightness (brightness, i.e., the intensity of light). In this specification, color may also be defined by only any one or only any two of the above three elements. In this specification, the difference in color between two lights refers to the difference in at least one of the above three elements, and also includes the difference in the shape of the spectrum of the two lights or the distribution of the relative intensity of each peak in the spectrum.

[0240] In addition, the words "film" and "layer" may be interchanged depending on the situation or state. For example, the word "conductive layer" may be interchanged with the word "conductive film" and the word "insulating film" may be interchanged with the word "insulating layer".

[0241] Implementation Method 1

[0242] In this embodiment, a heterocyclic compound which is one embodiment of the present invention is described.

[0243] One embodiment of the present invention is a heterocyclic compound represented by the general formula (G1).

[0244] [Chemical formula 38]

[0245]

[0246] In the general formula, A represents any one of a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted dibenzofuranyl group, and a substituted or unsubstituted carbazolyl group. DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. In addition, n is 0 or 1. Ar 1 To Ar 4 Each independently represents a substituted or unsubstituted arylene group having 6 to 10 carbon atoms. 1 To Ar 4 Adjacent arylene groups in Ar may also be bonded to each other to form a ring. 1 To Ar 4 When the adjacent arylene groups in form a fluorene skeleton, the fluorene skeleton may have a substituent.

[0247] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G2-1). This heterocyclic compound is useful from the viewpoint of ease of synthesis and synthesis cost.

[0248] [Chemical formula 39]

[0249]

[0250] In the general formula, R 18 To R 20 Any one of them represents a substituent represented by the general formula (G2-2).18 To R 20 The other two, R 11 To R 17 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0251] [Chemical formula 40]

[0252]

[0253] In the general formula, A represents any one of a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted dibenzofuranyl group, and a substituted or unsubstituted carbazolyl group. In addition, n is 0 or 1. Ar 1 To Ar 4 Each independently represents a substituted or unsubstituted arylene group having 6 to 10 carbon atoms. 1 To Ar 4 Adjacent arylene groups in Ar may also be bonded to each other to form a ring. 1 To Ar 4 When the adjacent arylene groups in form a fluorene skeleton, the fluorene skeleton may have a substituent.

[0254] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G3-1).

[0255] [Chemical formula 41]

[0256]

[0257] In the general formula, R 27 and R 28 Any one of them represents a substituent represented by the general formula (G3-2). 27 and R 28 Another one in R 21 To R 26 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. Z represents oxygen, sulfur, or nitrogen. When Z represents nitrogen, the substituent may or may not be bonded to the Z position.

[0258] [Chemical formula 42]

[0259]

[0260] In the general formula, DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. In addition, n is 0 or 1. Ar 1 To Ar 4 Each independently represents a substituted or unsubstituted arylene group having 6 to 10 carbon atoms. 1To Ar 4 Adjacent arylene groups in Ar may also be bonded to each other to form a ring. 1 To Ar 4 When the adjacent arylene groups in form a fluorene skeleton, the fluorene skeleton may have a substituent.

[0261] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G4-1).

[0262] [Chemical formula 43]

[0263]

[0264] In the general formula, R 31 , R 33 and R 34 Any one of them represents a substituent represented by the general formula (G4-2). 31 , R 33 and R 34 The substituent represented by the general formula (G4-2) is not bonded to the other two, R 32 , R 35 To R 39 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0265] [Chemical formula 44]

[0266]

[0267] In the general formula, DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. In addition, n is 0 or 1. Ar 1 To Ar 4 Each independently represents a substituted or unsubstituted arylene group having 6 to 10 carbon atoms. 1 To Ar 4 Adjacent arylene groups in Ar may also be bonded to each other to form a ring. 1 To Ar 4 When the adjacent arylene groups in form a fluorene skeleton, the fluorene skeleton may have a substituent.

[0268] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G5-1). This heterocyclic compound is useful from the viewpoint of ease of synthesis and synthesis cost.

[0269] [Chemical formula 45]

[0270]

[0271] In the general formula, R 27 and R28 Any one of them represents a substituent represented by the general formula (G5-2). 27 and R 28 Another one in R 21 To R 26 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. Z represents oxygen, sulfur, or nitrogen. When Z represents nitrogen, the substituent may or may not be bonded to the Z position.

[0272] [Chemical formula 46]

[0273]

[0274] In the general formula, R 11 To R 19 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. In addition, n is 0 or 1. Ar 1 To Ar 4 Each independently represents a substituted or unsubstituted arylene group having 6 to 10 carbon atoms. 1 To Ar 4 Adjacent arylene groups in Ar may also be bonded to each other to form a ring. 1 To Ar 4 When the adjacent arylene groups in form a fluorene skeleton, the fluorene skeleton may have a substituent.

[0275] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-1). This heterocyclic compound is useful from the viewpoint of high carrier transportability and high reliability.

[0276] [Chemical formula 47]

[0277]

[0278] In the general formula, DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxaline group. Z represents oxygen or sulfur. 21 To R 27 , R 41 To R 44 , R 51 To R 54 and R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0279] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-1), wherein the substitution position of DBq is the meta position.

[0280] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-1), wherein the substitution position of DBq is the meta position and the substitution position of the dibenzothienyl group or the dibenzofuranyl group is the para position.

[0281] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-2). This heterocyclic compound is useful from the viewpoint of high carrier transport properties and high reliability.

[0282] [Chemical formula 48]

[0283]

[0284] In the general formula, DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. Z represents oxygen or sulfur. 21 To R 27 , R 41 To R 44 , R 51 To R 54 and R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0285] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-3). This heterocyclic compound is useful from the viewpoint of high carrier transport properties and high reliability.

[0286] [Chemical formula 49]

[0287]

[0288] In the general formula, DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. 32 To R 39 , R 41 To R 44 , R 51 To R 54 and R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0289] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-3), wherein the substitution position of DBq is the meta position.

[0290] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-3), wherein the substitution position of DBq is the meta position and the substitution position of the carbazole group is the para position.

[0291] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-4). This heterocyclic compound is useful from the viewpoint of high carrier transport properties and high reliability.

[0292] [Chemical formula 50]

[0293]

[0294] In the general formula, DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. 32 To R 39 , R 41 To R 44 , R 51 To R 54 and R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0295] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-5). This heterocyclic compound is useful from the viewpoint of high carrier transport properties and high reliability.

[0296] [Chemical formula 51]

[0297]

[0298] In the general formula, DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. 31 represents an alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. 32 To R 36 , R 38 , R 39 , R 41 To R 44 , R 51 To R 54 and R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0299] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-5), wherein the substitution position of DBq is the meta position.

[0300] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-5), wherein the substitution position of DBq is the meta position and the substitution position of the carbazole group is the para position.

[0301] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-6). This heterocyclic compound is useful from the viewpoint of high carrier transport properties and high reliability.

[0302] [Chemical formula 52]

[0303]

[0304] In the general formula, DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. 31 represents an alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. 32 To R 36 , R 38 , R 39 , R 41 To R 44 , R 51 To R 54 and R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0305] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-7). This heterocyclic compound is useful from the viewpoint of high carrier transport properties and high reliability.

[0306] [Chemical formula 53]

[0307]

[0308] In the general formula, DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. 31 represents an alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. 32 To R 37 , R 39 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0309] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-7), wherein the substitution position of DBq is the meta position.

[0310] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-7), wherein the substitution position of DBq is the meta position and the substitution position of the carbazole group is the para position.

[0311] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G6-8). This heterocyclic compound is useful from the viewpoint of high carrier transport properties and high reliability.

[0312] [Chemical formula 54]

[0313]

[0314] In the general formula, DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxalinyl group. 31 represents an alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. 32 To R 37 , R 39 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0315] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G7-1). This heterocyclic compound is useful from the viewpoint of high carrier transport properties and high reliability.

[0316] [Chemical formula 55]

[0317]

[0318] In the general formula, A represents any one of a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted dibenzofuranyl group, and a substituted or unsubstituted carbazolyl group. 11 To R 19 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0319] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G7-1), wherein the substitution position of DBq is the meta position.

[0320] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G7-1), wherein the substitution position of DBq is the meta position and the substitution position of A is the para position.

[0321] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G7-2). This heterocyclic compound is useful from the viewpoint of high carrier transport properties and high reliability.

[0322] [Chemical formula 56]

[0323]

[0324] In the general formula, A represents any one of a substituted or unsubstituted dibenzothiophenyl group, a substituted or unsubstituted dibenzofuranyl group, and a substituted or unsubstituted carbazolyl group. 11 To R 19 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0325] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-1). This heterocyclic compound is useful from the viewpoint of high carrier transport properties and high reliability.

[0326] [Chemical formula 57]

[0327]

[0328] In the general formula, Z represents oxygen or sulfur. 11 To R 19 , R 21 To R 27 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0329] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-1), wherein the substitution position of DBq is the meta position.

[0330] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-1), wherein the substitution position of DBq is the meta position and the substitution position of the dibenzothienyl group or the dibenzofuranyl group is the para position.

[0331] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-2). This heterocyclic compound is useful from the viewpoint of high carrier transport properties and high reliability.

[0332] [Chemical formula 58]

[0333]

[0334] In the general formula, Z represents oxygen or sulfur. 11 To R 19 , R 21 To R 27 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0335] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-3). This heterocyclic compound is useful from the viewpoint of high carrier transport properties and high reliability.

[0336] [Chemical formula 59]

[0337]

[0338] In the general formula, R 11 To R 19 , R 32 To R 39 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0339] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-3), wherein the substitution position of DBq is the meta position.

[0340] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-3), wherein the substitution position of DBq is the meta position and the substitution position of the carbazole group is the para position.

[0341] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-4). This heterocyclic compound is useful from the viewpoint of high carrier transport properties and high reliability.

[0342] [Chemical formula 60]

[0343]

[0344] In the general formula, R 11 To R 19 , R 32 To R 39 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 Each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0345] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-5). This heterocyclic compound is useful from the viewpoint of high carrier transport properties and high reliability.

[0346] [Chemical formula 61]

[0347]

[0348] In the general formula, R 11 To R 19 , R 32 To R 36 , R 38 , R 39 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 R each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. 31 It represents an alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0349] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-5), wherein the substitution position of DBq is the meta position.

[0350] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-5), wherein the substitution position of DBq is the meta position and the substitution position of the carbazole group is the para position.

[0351] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-6). This heterocyclic compound is useful from the viewpoint of high carrier transport properties and high reliability.

[0352] [Chemical formula 62]

[0353]

[0354] In the general formula, R 11 To R 19 , R 32 To R 36 , R 38 , R 39 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 R each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. 31 It represents an alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0355] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-7). This heterocyclic compound is useful from the viewpoint of high carrier transport properties and high reliability.

[0356] [Chemical formula 63]

[0357]

[0358] In the general formula, R 11 To R 19 , R 32 To R 37 , R 39 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 R each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. 31 It represents an alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0359] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-7), wherein the substitution position of DBq is the meta position.

[0360] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-7), wherein the substitution position of DBq is the meta position and the substitution position of the carbazole group is the para position.

[0361] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G8-8). This heterocyclic compound is useful from the viewpoint of high carrier transport properties and high reliability.

[0362] [Chemical formula 64]

[0363]

[0364] In the general formula, R 11 To R 19 , R 32 To R 37 , R 39 , R 41 To R 44 , R 51 To R 54 , R 61 To R 64 R each independently represents hydrogen, an alkyl group having 1 to 4 carbon atoms, or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms. 31 It represents an alkyl group having 1 to 4 carbon atoms or a substituted or unsubstituted aryl group having 6 to 13 carbon atoms.

[0365] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G9-1). This heterocyclic compound is useful from the viewpoints of high T1 level, high carrier transportability, high heat resistance, and high reliability.

[0366] [Chemical formula 65]

[0367]

[0368] In the general formula, Z represents oxygen or sulfur.

[0369] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G9-2). This heterocyclic compound is useful from the viewpoints of high T1 level, high carrier transportability, high heat resistance, and high reliability.

[0370] [Chemical formula 66]

[0371]

[0372] In the general formula, Z represents oxygen or sulfur.

[0373] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G9-3). This heterocyclic compound is useful from the viewpoints of high T1 level, high carrier transportability, high heat resistance, and high reliability.

[0374] [Chemical formula 67]

[0375]

[0376] In the general formula, Z represents oxygen or sulfur.

[0377] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G9-4). This heterocyclic compound is useful from the viewpoints of high T1 level, high carrier transportability, high heat resistance, and high reliability.

[0378] [Chemical formula 68]

[0379]

[0380] In the general formula, Z represents oxygen or sulfur.

[0381] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G9-5). This heterocyclic compound is useful from the viewpoints of high T1 level, high carrier transportability, high heat resistance, and high reliability.

[0382] [Chemical formula 69]

[0383]

[0384] In the general formula, Z represents oxygen or sulfur.

[0385] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G10-1). This heterocyclic compound is useful from the viewpoints of high T1 level, high carrier transportability, high heat resistance, and high reliability.

[0386] [Chemical formula 70]

[0387]

[0388] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G10-2). This heterocyclic compound is useful from the viewpoints of high T1 level, high carrier transportability, high heat resistance, and high reliability.

[0389] [Chemical formula 71]

[0390]

[0391] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G10-3). This heterocyclic compound is useful from the viewpoints of high T1 level, high carrier transportability, high heat resistance, and high reliability.

[0392] [Chemical formula 72]

[0393]

[0394] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G10-4). This heterocyclic compound is useful from the viewpoints of high carrier transport properties, high heat resistance, and high reliability.

[0395] [Chemical formula 73]

[0396]

[0397] Another embodiment of the present invention is a heterocyclic compound represented by the general formula (G10-5). This heterocyclic compound is useful from the viewpoints of high T1 level, high carrier transportability, high heat resistance, and high reliability.

[0398] [Chemical formula 74]

[0399]

[0400] Examples of substituents possessed by the heterocyclic compound of one embodiment of the present invention are shown below. The following formulas (S01) to (S25) are R 11 To R 19 , R 21 To R 27 , R 32 To R 39 , R 41 To R 44 , R 51 To R 54 and R 61 To R 64 Specific examples of the following formula (S02) to formula (S25) are R 31 The following formulas (S31) to (S46) show Ar 1 To Ar 4 Note that one embodiment of the present invention is not limited to the following example.

[0401] [Chemical formula 75]

[0402]

[0403] [Chemical formula 76]

[0404]

[0405] The specific structure of the heterocyclic compound of the embodiment of the present invention is shown below. Note that the heterocyclic compound of the embodiment of the present invention is not limited to the following examples.

[0406] [Chemical formula 77]

[0407]

[0408] [Chemical formula 78]

[0409]

[0410] [Chemical formula 79]

[0411]

[0412] [Chemical formula 80]

[0413]

[0414] [Chemical formula 81]

[0415]

[0416] [Chemical formula 82]

[0417]

[0418] [Chemical formula 83]

[0419]

[0420] [Chemical formula 84]

[0421]

[0422] [Chemical formula 85]

[0423]

[0424] [Chemical formula 86]

[0425]

[0426] [Chemical formula 87]

[0427]

[0428] [Chemical formula 88]

[0429]

[0430] [Chemical formula 89]

[0431]

[0432] [Chemical formula 90]

[0433]

[0434] [Chemical formula 91]

[0435]

[0436] [Chemical formula 92]

[0437]

[0438] [Chemical formula 93]

[0439]

[0440] [Chemical formula 94]

[0441]

[0442] [Chemical formula 95]

[0443]

[0444] [Chemical formula 96]

[0445]

[0446] [Chemical formula 97]

[0447]

[0448] [Chemical formula 98]

[0449]

[0450] [Chemical formula 99]

[0451]

[0452] [Chemical formula 100]

[0453]

[0454] [Chemical Formula 101]

[0455]

[0456] [Chemical formula 102]

[0457]

[0458] [Chemical formula 103]

[0459]

[0460] [Chemical formula 104]

[0461]

[0462] [Chemical formula 105]

[0463]

[0464] [Chemical formula 106]

[0465]

[0466] [Chemical formula 107]

[0467]

[0468] [Chemical formula 108]

[0469]

[0470] [Chemical formula 109]

[0471]

[0472] [Chemical formula 110]

[0473]

[0474] [Chemical formula 111]

[0475]

[0476] [Chemical formula 112]

[0477]

[0478] [Chemical formula 113]

[0479]

[0480] [Chemical formula 114]

[0481]

[0482] [Chemical formula 115]

[0483]

[0484] [Chemical formula 116]

[0485]

[0486] [Chemical formula 117]

[0487]

[0488] [Chemical formula 118]

[0489]

[0490] [Chemical formula 119]

[0491]

[0492] [Chemical formula 120]

[0493]

[0494] [Chemical formula 121]

[0495]

[0496] [Chemical formula 122]

[0497]

[0498] [Chemical formula 123]

[0499]

[0500] [Chemical formula 124]

[0501]

[0502] [Chemical formula 125]

[0503]

[0504] [Chemical formula 126]

[0505]

[0506] [Chemical formula 127]

[0507]

[0508] [Chemical formula 128]

[0509]

[0510] [Chemical formula 129]

[0511]

[0512] [Chemical formula 130]

[0513]

[0514] [Chemical formula 131]

[0515]

[0516] [Chemical formula 132]

[0517]

[0518] [Chemical formula 133]

[0519]

[0520] [Chemical formula 134]

[0521]

[0522] [Chemical formula 135]

[0523]

[0524] [Chemical formula 136]

[0525]

[0526] [Chemical formula 137]

[0527]

[0528] [Chemical formula 138]

[0529]

[0530] [Chemical formula 139]

[0531]

[0532] [Chemical formula 140]

[0533]

[0534] [Chemical formula 141]

[0535]

[0536] [Chemical formula 142]

[0537]

[0538] [Chemical formula 143]

[0539]

[0540] [Chemical formula 144]

[0541]

[0542] [Chemical formula 145]

[0543]

[0544] [Chemical formula 146]

[0545]

[0546] [Chemical formula 147]

[0547]

[0548] [Chemical formula 148]

[0549]

[0550] [Chemical formula 149]

[0551]

[0552] [Chemical formula 150]

[0553]

[0554] [Chemical formula 151]

[0555]

[0556] [Chemical formula 152]

[0557]

[0558] [Chemical formula 153]

[0559]

[0560] [Chemical formula 154]

[0561]

[0562] [Chemical formula 155]

[0563]

[0564] [Chemical formula 156]

[0565]

[0566] [Chemical formula 157]

[0567]

[0568] [Chemical formula 158]

[0569]

[0570] [Chemical formula 159]

[0571]

[0572] [Chemical formula 160]

[0573]

[0574] [Chemical formula 161]

[0575]

[0576] [Chemical formula 162]

[0577]

[0578] [Chemical formula 163]

[0579]

[0580] [Chemical formula 164]

[0581]

[0582] [Chemical formula 165]

[0583]

[0584] [Chemical formula 166]

[0585]

[0586] [Chemical formula 167]

[0587]

[0588] [Chemical formula 168]

[0589]

[0590] [Chemical formula 169]

[0591]

[0592] [Chemical formula 170]

[0593]

[0594] [Chemical formula 171]

[0595]

[0596] [Chemical formula 172]

[0597]

[0598] [Chemical formula 173]

[0599]

[0600] [Chemical formula 174]

[0601]

[0602] [Chemical formula 175]

[0603]

[0604] [Chemical formula 176]

[0605]

[0606] [Chemical formula 177]

[0607]

[0608] [Chemical formula 178]

[0609]

[0610] [Chemical formula 179]

[0611]

[0612] [Chemical formula 180]

[0613]

[0614] [Chemical formula 181]

[0615]

[0616] [Chemical formula 182]

[0617]

[0618] [Chemical formula 183]

[0619]

[0620] [Chemical formula 184]

[0621]

[0622] [Chemical formula 185]

[0623]

[0624] [Chemical formula 186]

[0625]

[0626] [Chemical formula 187]

[0627]

[0628] [Chemical formula 188]

[0629]

[0630] [Chemical formula 189]

[0631]

[0632] [Chemical formula 190]

[0633]

[0634] [Chemical formula 191]

[0635]

[0636] [Chemical formula 192]

[0637]

[0638] [Chemical formula 193]

[0639]

[0640] [Chemical formula 194]

[0641]

[0642] [Chemical formula 195]

[0643]

[0644] [Chemical formula 196]

[0645]

[0646] [Chemical formula 197]

[0647]

[0648] [Chemical formula 198]

[0649]

[0650] [Chemical formula 199]

[0651]

[0652] [Chemical formula 200]

[0653]

[0654] [Chemical formula 201]

[0655]

[0656] [Chemical formula 202]

[0657]

[0658] [Chemical formula 203]

[0659]

[0660] [Chemical formula 204]

[0661]

[0662] [Chemical formula 205]

[0663]

[0664] [Chemical formula 206]

[0665]

[0666] [Chemical formula 207]

[0667]

[0668] [Chemical formula 208]

[0669]

[0670] [Chemical formula 209]

[0671]

[0672] [Chemical formula 210]

[0673]

[0674] [Chemical formula 211]

[0675]

[0676] [Chemical formula 212]

[0677]

[0678] [Chemical formula 213]

[0679]

[0680] [Chemical formula 214]

[0681]

[0682] [Chemical formula 215]

[0683]

[0684] [Chemical formula 216]

[0685]

[0686] [Chemical formula 217]

[0687]

[0688] [Chemical formula 218]

[0689]

[0690] [Chemical formula 219]

[0691]

[0692] [Chemical formula 220]

[0693]

[0694] [Chemical formula 221]

[0695]

[0696] [Chemical formula 222]

[0697]

[0698] [Chemical formula 223]

[0699]

[0700] [Chemical formula 224]

[0701]

[0702] The heterocyclic compound of one embodiment of the present invention has a structure in which a dibenzothiophenyl group, a dibenzofuranyl group or a carbazolyl group and a dibenzo[f,h]quinoxalinyl group are bonded via three or more arylene groups. The heterocyclic compound of one embodiment of the present invention can be used as a host material in a light-emitting layer constituting an EL layer.

[0703] The main material in the light-emitting layer is required to have various properties and functions, among which high heat resistance can be cited as one of the important properties. When the glass transition temperature (Tg) of the material is used as an indicator of the heat resistance of the material, it can be said that the higher the glass transition temperature (Tg) of the main material, the higher the heat resistance. The glass transition temperature (Tg) of the material is roughly proportional to the molecular weight of the material. Therefore, in order to improve the heat resistance of the material, the molecular weight of the material can be increased.

[0704] Generally speaking, the glass transition temperature (Tg) of organic materials tends to be higher as the molecular weight increases. However, there is also a trend that the sublimation temperature or boiling point in the sublimation purification or distillation performed in the purification process also increases due to the improvement of heat resistance. Many common low-molecular organic compounds decompose above 400°C. In addition, the sublimation temperature or boiling point increases when the molecular weight is increased alone. Therefore, the temperature in the film forming process such as deposition by evaporation or the purification process such as sublimation purification and distillation needs to be increased, which will lead to decomposition.

[0705] That is, when the molecular weight is simply increased in order to improve the thermal properties of the host material, the possibility of decomposition in the purification process or the film formation process becomes high, and therefore it may be difficult to use a highly purified organic compound in a device.

[0706] On the other hand, although the heterocyclic compound of one embodiment of the present invention has a molecular weight increased to improve thermal properties, the decomposition temperature of the heterocyclic compound is relatively high, and the heat resistance thereof is greatly improved by adding at least one benzene ring. Therefore, decomposition is not likely to occur in the purification process or the evaporation process, and a material with high purity can be used for the element. That is, a component with high heat resistance and good characteristics can be provided.

[0707] Generally speaking, the larger the molecular weight of an organic material, the higher the refractive index. When the molecular weight of a host material used for a light-emitting layer is increased, not only the glass transition temperature (Tg) but also the refractive index of the light-emitting layer will increase.

[0708] The light generated in the light-emitting layer passes through the EL layer, the transparent electrode, and through the glass substrate and the resin film into the air. When the light passes through the boundaries between these components, various optical phenomena occur due to the difference in refractive index. That is, depending on the angle at which the light enters the boundary, the high and low relationship between the refractive indices of the components through which the light passes, or the degree of the difference between the refractive indices, for example, the light emitted from the EL layer returns in the direction of the EL layer (total reflection) or is refracted in an unexpected direction. As a result, the intensity of the light reaching the outside of the light-emitting element decreases, and the light extraction efficiency or external quantum efficiency of the light-emitting element decreases.

[0709] That is, if the molecular weight of the host material is simply increased in order to improve the thermophysical properties of the host material, the refractive index increases, and thus the light extraction efficiency or external quantum efficiency of a light-emitting element including a light-emitting layer using the host material decreases, which causes a problem.

[0710] However, although the heterocyclic compound of one embodiment of the present invention has a molecular weight increased to improve thermal properties, using the heterocyclic compound as a host material of a light-emitting layer of a light-emitting element does not reduce the light extraction efficiency or external quantum efficiency of the light-emitting element.

[0711] The heterocyclic compound of one embodiment of the present invention has a molecular structure with three or more linked arylene groups as the long axis. When a film of the heterocyclic compound is formed as a main material of a light-emitting layer, the orientation of the formed film tends to have the long axis of each molecule tilted in a direction substantially parallel to the substrate. Molecules having a long axis sometimes have anisotropy of the refractive index, and the heterocyclic compound of one embodiment of the present invention also tends to have anisotropy of the refractive index.

[0712] In the case of using three or more arylene groups to increase the molecular weight, it is possible that the molecule becomes larger in the long axis direction and the refractive index in the long axis direction becomes higher, but it is considered that the change in the molecular size in the short axis direction is not large. Therefore, the change in the refractive index in the short axis direction is small. When the heterocyclic compound of one embodiment of the present invention is used for the light-emitting layer, the film of the heterocyclic compound tends to be formed in a manner with its short axis facing the light extraction direction, so the effective refractive index of the light-emitting layer is roughly the same as the effective refractive index of the light-emitting layer of the heterocyclic compound using a small number of arylene groups. However, since the molecule becomes larger in the long axis direction and the molecular weight also becomes larger, the thermal properties are improved.

[0713] For example, the heterocyclic compound of one embodiment of the present invention is different from 2-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviated as: 2mDBTBPDBq-II) which has excellent properties as a host material in that the number of arylene groups is 3 or more, so the effective refractive index is maintained while improving the thermal properties. As a result, the light extraction efficiency or external quantum efficiency of the light-emitting element is not reduced.

[0714] Furthermore, there is a tendency that when the heterocyclic compound of one embodiment of the present invention is oriented in the light-emitting layer, the dopant molecules (also referred to as guest materials) are also oriented. When some dopant molecules are oriented in a specific direction, the luminous intensity of light toward the outside of the light-emitting element becomes higher, and the external quantum efficiency of the light-emitting element is improved. This is because the light emitted by the dopant molecules is also anisotropic like the refractive index. That is, the main material of the light-emitting element preferably improves the orientation of the dopant. That is, the heterocyclic compound of one embodiment of the present invention can control the orientation of the dopant molecules to further improve the external quantum efficiency of the light-emitting element.

[0715] Therefore, the heterocyclic compound of one embodiment of the present invention has very useful properties as a host material.

[0716] This embodiment mode can be combined with any other embodiment mode as appropriate.

[0717] Implementation Method 2

[0718] In this embodiment, a method for synthesizing an organic compound represented by the general formula (G1) is described.

[0719] [Chemical formula 225]

[0720]

[0721] Various reactions can be used as a method for synthesizing an organic compound represented by the general formula (G1). For example, an organic compound represented by the general formula (G1) can be synthesized by performing the following synthesis reaction. Note that the method for synthesizing an organic compound represented by the general formula (G1) of one embodiment of the present invention is not limited to the following synthesis method.

[0722] <Method for synthesizing organic compounds represented by general formula (G1)>

[0723] An organic compound represented by the general formula (G1) according to one embodiment of the present invention can be synthesized through the following synthesis scheme (a-1). That is, a compound represented by the general formula (G1) can be obtained by coupling a dibenzo[f,h]quinoxaline compound (Compound 1) with a dibenzothiophene compound or a dibenzofuran compound (Compound 2).

[0724] [Chemical formula 226]

[0725]

[0726] In the synthesis scheme (a-1), DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxaline group, n is 0 or 1, A represents a substituted or unsubstituted dibenzothiophenyl group and a substituted or unsubstituted dibenzofuranyl group, and Ar 1 ,Ar 2 ,Ar 3 ,Ar 4 Each independently represents an arylene group having 6 to 10 carbon atoms. The above arylene group may have one or more substituents. The above substituents may also be bonded to each other to form a ring. 1 To Ar 4 Adjacent arylene groups in the arylene group may be linked to each other by methylene groups to form a structure having a fluorene skeleton.

[0727] In the synthesis scheme (a-1), when the Suzuki-Miyaura coupling reaction using a palladium catalyst is carried out, X 1 and X 2 Respectively independently represent halogen, boric acid group, organic boron group or trifluoromethylsulfonyl group, halogen is preferably iodine, bromine or chlorine. In the above reaction, palladium compounds such as bis(dibenzylideneacetone)palladium(0), palladium acetate(II), [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II), tetrakis(triphenylphosphine)palladium(0) and tri(tert-butyl)phosphine, tri(n-hexyl)phosphine, tricyclohexylphosphine, di(1-adamantyl)-n-butylphosphine, 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl, tri(o-tolyl)phosphine and the like can be used. In the reaction, organic bases such as sodium tert-butoxide, potassium carbonate, cesium carbonate, sodium carbonate and other inorganic bases can be used. In addition, in the reaction, toluene, xylene, benzene, tetrahydrofuran, dioxane, ethanol, methanol, water and the like can be used as solvents. Note that the reagents that can be used for the above reaction are not limited to the above reagents.

[0728] The reaction performed in the synthesis scheme (a-1) is not limited to the Suzuki-Miyaura coupling reaction, and the Ueda-Kosugi-Stille coupling reaction using an organic tin compound, the Kumada-Tamao-Corriu coupling reaction using a Grignard reagent, the Negishi coupling reaction using an organic zinc compound, the reaction using copper or a copper compound, etc. can also be used. When the Ueda-Kosugi-Stille coupling reaction is used, X 1 and X 2 One of the compounds 1 and 2 represents an organotin group and the other represents a halogen. That is, one of the compounds 1 and 2 represents an organotin compound. When the Kumada-Tamago-Corriu coupling reaction is used, X 1 and X 2 One of the compounds 1 and 2 represents a magnesium halide group and the other represents a halogen. That is, one of the compounds 1 and 2 represents a Grignard reagent. When the Negishi coupling reaction is used, X 1 and X 2 One of them represents an organozinc group and the other represents a halogen. That is, one of Compound 1 and Compound 2 represents an organozinc compound.

[0729] Note that in the synthesis of an organic compound represented by the general formula (G1) of one embodiment of the present invention, the synthesis method is not limited to the synthesis method (a-1). For example, the synthesis can be carried out through the following synthesis schemes (a-2) to (a-4). That is, by coupling a dibenzo[f,h]quinoxaline compound (compound 3, 5 or 7) with a dibenzothiophene compound or a dibenzofuran compound (compound 4, 6 or 8), a compound represented by the general formula (G1) can be obtained.

[0730] [Chemical formula 227]

[0731]

[0732] [Chemical formula 228]

[0733]

[0734] [Chemical formula 229]

[0735]

[0736] In the synthesis schemes (a-2) to (a-4), DBq represents a substituted or unsubstituted dibenzo[f,h]quinoxaline group, n is 0 or 1, A represents any one of a substituted or unsubstituted dibenzothiophenyl group and a substituted or unsubstituted dibenzofuranyl group, and Ar 1 ,Ar 2 ,Ar 3 ,Ar 4 Each independently represents an arylene group having 6 to 10 carbon atoms. The above arylene group may have one or more substituents. The above substituents may also be bonded to each other to form a ring. 1 To Ar 4 Adjacent arylene groups in the arylene group may be linked to each other by methylene groups to form a structure having a fluorene skeleton.

[0737] In the synthesis schemes (a-2) to (a-4), when the Suzuki-Miyaura coupling reaction using a palladium catalyst is performed, X 3 To X 8 Each independently represents a halogen, a boronic acid group, an organic boronic group or a trifluoromethylsulfonyl group, and the halogen is preferably iodine, bromine or chlorine. The reagents that can be used here are the same as those in the synthesis scheme (a-1), and are not limited to the above reagents.

[0738] The reactions carried out in the synthesis schemes (a-2) to (a-4) are not limited to the Suzuki-Miyaura coupling reaction, and the Ueda-Kosugi-Stille coupling reaction using an organic tin compound, the Kumada-Tamao-Corriu coupling reaction using a Grignard reagent, the Negishi coupling reaction using an organic zinc compound, the reaction using copper or a copper compound, etc. can also be used.

[0739] When using these reactions, 3 To X 8 and X in the synthesis scheme (a-1) 1 and X 2Same. That is, when using the Ueda-Kosugi-Stille coupling reaction, in each reaction, one X represents an organotin group and the other X represents a halogen. That is, in each reaction, one of compound 3 and compound 4, one of compound 5 and compound 6, and one of compound 7 and compound 8 represent an organotin compound. When using the Kumada-Tamago-Corriu coupling reaction, in each reaction, X 3 To X 8 In each reaction, one X of Compound 3 and Compound 4, one of Compound 5 and Compound 6, and one of Compound 7 and Compound 8 represents a Grignard reagent, and the other of Compound 3 and Compound 4, the other of Compound 5 and Compound 6, and the other of Compound 7 and Compound 8 represents a halogen. When the Negishi coupling reaction is used, in each reaction, X 3 To X 8 One X in represents an organozinc group, and the other X represents a halogen. That is, in each reaction, one of Compound 3 and Compound 4, one of Compound 5 and Compound 6, and one of Compound 7 and Compound 8 represents an organozinc compound.

[0740] When a coupling reaction of a dibenzo[f,h]quinoxaline compound with a dibenzothiophene compound or a dibenzofuran compound is carried out, DBq, Ar 1 To Ar 4 , A can be subjected to coupling reaction at any position. Note that the method for synthesizing the heterocyclic compound of one embodiment of the present invention is not limited thereto.

[0741] As described above, an example of a method for synthesizing a compound according to one embodiment of the present invention has been described, but the present invention is not limited thereto, and any other synthesis method may be used.

[0742] In Embodiment 2, one embodiment of the present invention is described. In Embodiments 1 and 3 to 6, other embodiments of the present invention will be described. However, one embodiment of the present invention is not limited to the above examples. For example, an example in which a dibenzothiophenyl group, a dibenzofuranyl group or a carbazolyl group, and a dibenzo[f,h]quinoxaline group are bonded through three or more arylene groups is shown as one embodiment of the present invention, but one embodiment of the present invention is not limited to this example. Depending on circumstances or conditions, one embodiment of the present invention may also have a skeleton other than the following structure, i.e., a structure in which a dibenzothiophenyl group, a dibenzofuranyl group or a carbazolyl group, and a dibenzo[f,h]quinoxaline group are bonded through three or more arylene groups. For example, depending on circumstances or conditions, one embodiment of the present invention may not have a structure in which a dibenzothiophenyl group, a dibenzofuranyl group or a carbazolyl group, and a dibenzo[f,h]quinoxaline group are bonded through three or more arylene groups.

[0743] This embodiment mode can be combined with any other embodiment mode as appropriate.

[0744] Implementation 3

[0745] In this embodiment, refer to Figure 1A One embodiment of a light-emitting element including the heterocyclic compound of one embodiment of the present invention is described.

[0746] The light-emitting element in this embodiment includes a plurality of layers between a pair of electrodes. In this embodiment, the light-emitting element includes a first electrode 101, a second electrode 102, and an EL layer 103 provided between the first electrode 101 and the second electrode 102. Figure 1A In the embodiment, the first electrode 101 is used as an anode and the second electrode 102 is used as a cathode. That is, when a voltage is applied to the first electrode 101 and the second electrode 102 in such a manner that the potential of the first electrode 101 is higher than the potential of the second electrode 102, light emission can be obtained. Of course, a structure in which the first electrode is used as a cathode and the second electrode is used as an anode can also be adopted. In this case, the stacking order of the EL layer is opposite to the above order. In addition, in the light-emitting element shown in this embodiment, at least one layer of the EL layer 103 contains a heterocyclic compound of one embodiment of the present invention. The layer containing the heterocyclic compound is preferably used as a light-emitting layer or an electron transport layer because the characteristics of the above-mentioned heterocyclic compound can be effectively utilized and the light-emitting element can have good characteristics.

[0747] As an electrode used as an anode, it is preferred to use any one of metals, alloys, conductive compounds, and mixtures thereof having a large work function (specifically, a work function of 4.0 eV or more). Specifically, for example, indium tin oxide (ITO: Indium Tin Oxide), indium tin oxide containing silicon or silicon oxide, indium oxide-zinc oxide, indium oxide containing tungsten oxide and zinc oxide (IWZO), etc. can be cited. Although these conductive metal oxide films are usually formed by sputtering, they can also be formed by applying a sol-gel method. For example, indium oxide-zinc oxide can be formed by sputtering using a target material in which zinc oxide of 1 wt% or more and 20 wt% or less is added to indium oxide. In addition, indium oxide (IWZO) containing tungsten oxide and zinc oxide can be formed by sputtering using a target material in which tungsten oxide of 0.5 wt% or more and 5 wt% or less is added to indium oxide and zinc oxide of 0.1 wt% or more and 1 wt% or less is added to indium oxide. In addition, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chromium (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), and nitrides of metal materials (e.g., titanium nitride) can be cited. In addition, graphene can also be used.

[0748] There is no particular limitation on the stacked structure of the EL layer 103. The EL layer 103 is formed by appropriately combining a layer containing a substance with high electron transport properties, a layer containing a substance with high hole transport properties, a layer containing a substance with high electron injection properties, a layer containing a substance with high hole injection properties, a layer containing a substance with bipolar properties (a substance with high electron and hole transport properties), and a layer with carrier blocking properties. In this embodiment, the EL layer 103 has a structure in which a hole injection layer 111, a hole transport layer 112, a light-emitting layer 113, an electron transport layer 114, and an electron injection layer 115 are stacked in sequence on an electrode used as an anode. The materials constituting each layer are specifically shown below.

[0749] The hole injection layer 111 is a layer containing a substance with high hole injection properties. As a substance with high hole injection properties, for example, molybdenum oxide, vanadium oxide, ruthenium oxide, tungsten oxide, manganese oxide, etc. can be used. In addition, phthalocyanine compounds such as phthalocyanine (abbreviated as: H2Pc), copper phthalocyanine (abbreviated as: CuPc), etc.; aromatic amine compounds such as 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviated as: DPAB), N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviated as: DNTPD), etc.; or polymer compounds such as poly(ethylenedioxythiophene) / poly(styrenesulfonic acid) (abbreviated as: PEDOT / PSS), etc. can also be used to form the hole injection layer 111.

[0750] As the hole injection layer 111, a composite material containing a substance having hole transport properties and a substance that exhibits electron accepting properties to the substance (hereinafter referred to as "electron accepting substance") can also be used. In this specification, "composite material" does not refer to a material formed by mixing only two materials, but also refers to a material that is mixed with multiple materials to be in a state where charges can be transferred between materials. The transfer of charges includes the transfer of charges that occurs only when an electric field is present.

[0751] Note that by using a composite material containing an electron acceptor substance in a substance having hole transport properties, it is possible to select a material to form an electrode without having to consider the work function of the material. That is, as an electrode used as an anode, in addition to materials with a large work function, materials with a small work function can also be used. As electron acceptor substances, 7,7,8,8-tetracyano-2,3,5,6-tetrafluoroquinodimethane (abbreviated as: F4-TCNQ), chloranil, etc. can be cited. Transition metal oxides can also be used. In particular, oxides of any metal belonging to Groups 4 to 8 in the periodic table can be appropriately used. Specifically, vanadium oxide, niobium oxide, tantalum oxide, chromium oxide, molybdenum oxide, tungsten oxide, manganese oxide, and rhenium oxide are preferably used because they have high electron acceptability. Among them, molybdenum oxide is particularly preferably used as an electron acceptor because it is also stable in the atmosphere, has low hygroscopicity, and is easy to handle.

[0752] As the substance with hole transport property used in the composite material, various organic compounds such as aromatic amine compounds, carbazole compounds, aromatic hydrocarbons, high molecular weight compounds (oligomers, dendrimers, polymers, etc.) can be used. As the organic compound used in the composite material, it is preferred to use an organic compound with high hole transport property. Specifically, it is preferred to use an organic compound with a hole mobility of 1 to 10 -6 cm 2 / Vs or more. Note that any substance other than the above substances may be used as long as it has a hole transporting property. The following specifically lists organic compounds that can be used as a substance having a hole transporting property in the composite material.

[0753] For example, as the aromatic amine compound, N,N'-di(p-tolyl)-N,N'-diphenyl-p-phenylenediamine (abbreviation: DTDPPA), 4,4'-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), N,N'-bis{4-[bis(3-methylphenyl)amino]phenyl}-N,N'-diphenyl-(1,1'-biphenyl)-4,4'-diamine (abbreviation: DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), etc. can be mentioned.

[0754] Specific examples of carbazole compounds that can be used in composite materials include 3-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviated as PCzPCA1), 3,6-bis[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviated as PCzPCA2), and 3-[N-(1-naphthyl)-N-(9-phenylcarbazole-3-yl)amino]-9-phenylcarbazole (abbreviated as PCzPCN1).

[0755] In addition, examples of carbazole compounds that can be used in composite materials include 4,4'-di(N-carbazolyl)biphenyl (abbreviation: CBP), 1,3,5-tris[4-(N-carbazolyl)phenyl]benzene (abbreviation: TCPB), 9-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole (abbreviation: CzPA), and 1,4-bis[4-(N-carbazolyl)phenyl]-2,3,5,6-tetraphenylbenzene.

[0756] Examples of aromatic hydrocarbons that can be used in composite materials include 2-tert-butyl-9,10-di(2-naphthyl)anthracene (abbreviated as t-BuDNA), 2-tert-butyl-9,10-di(1-naphthyl)anthracene, 9,10-bis(3,5-diphenylphenyl)anthracene (abbreviated as DPPA), 2-tert-butyl-9,10-bis(4-phenylphenyl)anthracene (abbreviated as t-BuDBA), 9,10-di(2-naphthyl)anthracene (abbreviated as DNA), 9,10-diphenylanthracene (abbreviated as DPAnth), 2-tert-butylanthracene (abbreviated as t-BuAnth), 9,10-bis(4-methyl-1-naphthyl)anthracene (abbreviated as DMNA ), 2-tert-butyl-9,10-bis[2-(1-naphthyl)phenyl]anthracene, 9,10-bis[2-(1-naphthyl)phenyl]anthracene, 2,3,6,7-tetramethyl-9,10-di(1-naphthyl)anthracene, 2,3,6,7-tetramethyl-9,10-di(2-naphthyl)anthracene, 9,9'-bianthracene, 10,10'-diphenyl-9,9'-bianthracene, 10,10'-bis(2-phenylphenyl)-9,9'-bianthracene, 10,10'-bis[(2,3,4,5,6-pentaphenyl)phenyl]-9,9'-bianthracene, anthracene, tetracene, rubrene, perylene, 2,5,8,11-tetra(tert-butyl)perylene, etc. In addition, pentacene, coronene, etc. can also be used. In particular, it is preferable to use a 1×10 -6 cm 2 An aromatic hydrocarbon having 14 to 42 carbon atoms and having a hole mobility of greater than / Vs.

[0757] Aromatic hydrocarbons that can be used in composite materials may also have a vinyl skeleton. Examples of aromatic hydrocarbons having a vinyl group include 4,4'-bis(2,2-diphenylvinyl)biphenyl (abbreviation: DPVBi) and 9,10-bis[4-(2,2-diphenylvinyl)phenyl]anthracene (abbreviation: DPVPA).

[0758] In addition, polymer compounds such as poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N'-[4-(4-diphenylamino)phenyl]phenyl-N'-phenylamino}phenyl)methacrylamide] (abbreviation: PTPDMA), and poly[N,N'-bis(4-butylphenyl)-N,N'-bis(phenyl)benzidine] (abbreviation: Poly-TPD) can also be used.

[0759] In addition, the composite material may include the compound having a structure described in Embodiment 1 in which a dibenzofuranyl group, a dibenzofuranyl group or a carbazole group, and a dibenzo[f,h]quinoxaline group are bonded via three or more arylene groups.

[0760] The hole transport layer 112 is a layer containing a substance having hole transport properties. As a substance having hole transport properties, the above-mentioned substance having hole transport properties that can be used for the composite material can be used. In addition, in order to avoid repetition, detailed description is omitted. See the description of the composite material. In addition, the hole transport layer may also include a compound having a structure described in Embodiment 1 having a dibenzofuranyl group, a dibenzofuranyl group or a carbazole group, and a dibenzo [f, h] quinoxaline group bonded by three or more arylene groups.

[0761] The light-emitting layer 113 is a layer containing a light-emitting substance. The light-emitting layer 113 may be composed of a film containing only a light-emitting substance, or may be composed of a film in which a light-emitting center substance is dispersed in a host material.

[0762] There is no particular limitation on the material that can be used as the luminescent substance or the luminescent center substance in the luminescent layer 113, and the light emitted by the material can be either fluorescence or phosphorescence. As the above-mentioned luminescent substance and luminescent center substance, for example, the following materials can be cited. As fluorescent luminescent substances, N,N'-diphenyl-N,N'-bis[4-(9-phenyl-9H-fluorene-9-yl)phenyl]pyrene-1,6-diamine (abbreviated as: 1,6FLPAPrn), N,N'-bis[4-(9H-carbazole-9-yl)phenyl]-N,N'-diphenylstilbene-4,4'-diamine (abbreviated as: YGA2S), 4-(9H-carbazole-9-yl)phenyl]pyrene-1,6-diamine (abbreviated as: 1,6FLPAPrn) can be cited. triphenylamine (abbreviated as: YGAPA), 4-(9H-carbazole-9-yl)-4'-(9,10-diphenyl-2-anthracenyl)triphenylamine (abbreviated as: 2YGAPPA), N,9-diphenyl-N-[4-(10-phenyl-9-anthracenyl)phenyl]-9H-carbazole-3-amine (abbreviated as: PCAPA), perylene, 2,5,8, 11-Tetra(tert-butyl)perylene (abbreviation: TBP), 4-(10-phenyl-9-anthracenyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviation: PCBAPA), N,N"-(2-tert-butylanthracene-9,10-diyldi-4,1-phenylene)bis[N,N',N'-triphenyl-1,4-phenylenediamine] (abbreviation: DPABPA), N,9-diphenyl-N-[4-(9,10-diphenyl-2-anthracenyl)phenyl]-9H-carbazole-3-amine (abbreviation: 2PCAPPA), N-[4-(9,10-diphenyl-2-anthracenyl)phenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPPA), N,N,N',N',N",N",N"',N"'-octaphenyldibenzo[g,p] (chrysene)-2,7,10,15-tetraamine (abbreviation: DBC1), coumarin 30, N-(9,10-diphenyl-2-anthracenyl)-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthracenyl]-N,9-diphenyl-9H-carbazole-3-amine (abbreviation: 2PCABPhA), N-(9,10-diphenyl-2-anthracenyl)-N,N',N'-triphenyl-1,4-phenylenediamine (abbreviation: 2DPAPA), N-[9,10-bis(1,1'-biphenyl-2-yl)-2-anthracenyl]-N,N',N'-triphenyl-1,4-phenylenediamine (Abbreviation: 2DPABPhA), 9,10-bis(1,1'-biphenyl-2-yl)-N-[4-(9H-carbazole-9-yl)phenyl]-N-phenylanthracen-2-amine (Abbreviation: 2YGABPhA), N,N,9-triphenylanthracen-9-amine (Abbreviation: DPhAPhA), coumarin 545T, N,N'-diphenylquinacridone (Abbreviation: DPQd), rubrene, 5,12-bis(1,1'-biphenyl-4-yl)-6,11-diphenylnaphthacene (Abbreviation: BPT), 2-(2-{2-[4-(dimethylamino)phenyl]vinyl}-6-methyl-4H-pyran-4-ylidene)malononitrile (Abbreviation: DCM1), 2-{2-methyl-6-[2 -(2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)vinyl]-4H-pyran-4-ylidene}malononitrile (abbreviation: DCM2), N,N,N',N'-tetrakis(4-methylphenyl)tetracene-5,11-diamine (abbreviation: p-mPhTD), 7,14-diphenyl-N,N,N',N'-tetrakis(4-methylphenyl)acenaphtho[1,2-a]fluoranthene-3,10-diamine (abbreviation: p-mPhAFD), 2-{2-isopropyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)vinyl]-4H-pyran-4-ylidene}malononitrile (abbreviation: DCM2), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)vinyl]-4H-pyran-4-ylidene}malononitrile (abbreviated as: DCJTI), 2-{2-tert-butyl-6-[2-(1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)vinyl]-4H-pyran-4-ylidene}malononitrile (abbreviated as: DCJTB), 2-(2,6-bis{2-[4-(dimethylamino)phenyl]vinyl}-4H-pyran-4-ylidene)malononitrile (abbreviated as: BisDCM), 2-{2,6-bis[2-(8-methoxy-1,1,7,7-tetramethyl-2,3,6,7-tetrahydro-1H,5H-benzo[ij]quinolizin-9-yl)vinyl]-4H-pyran-4-ylidene}malononitrile (abbreviated as: BisDCJTM), etc.As blue phosphorescent substances, there can be mentioned: organic metal iridium complexes having a 4H-triazole skeleton, such as tris{2-[5-(2-methylphenyl)-4-(2,6-dimethylphenyl)-4H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviated as Ir(mpptz-dmp)3), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviated as Ir(Mptz)3), tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviated as Ir(iPrptz-3b)3); tris[3-methyl-1-(2-methylphenyl)-5-phenyl-1H-1,2,4-triazol-3-yl-κN2]phenyl-κC}iridium(III) (abbreviated as Ir(mpptz-dmp)3), tris(5-methyl-3,4-diphenyl-4H-1,2,4-triazolato)iridium(III) (abbreviated as Ir(Mptz)3), and tris[4-(3-biphenyl)-5-isopropyl-3-phenyl-4H-1,2,4-triazolato]iridium(III) (abbreviated as Ir(iPrptz-3b)3); lato)]iridium (III) (abbreviated as: Ir(Mptz1-mp)3), tris(1-methyl-5-phenyl-3-propyl-1H-1,2,4-triazolato))iridium (III) (abbreviated as: Ir(Prptz1-Me)3), etc. having a 1H-triazole skeleton; fac-tris[1-(2,6-diisopropylphenyl)-2-phenyl-1H-imidazole]iridium (III) (abbreviated as: Ir(iPrpmi)3), tris[3-(2,6-dimethylphenyl)-7-methylimidazo[1,2-f]phenanthridinato]iridium (III) (abbreviated as: Ir(dmpimpt-Me)3), etc. having an imidazole skeleton; and bis[2-(4',6'-difluorophenyl)pyridinium-N,C. 2 '] iridium (III) tetrakis (1-pyrazolyl) borate (abbreviated as FIr6), bis [2-(4', 6'-difluorophenyl) pyridinium-N, C 2 '] iridium (III) picolinate (abbreviated as FIrpic), bis{2-[3',5'-bis(trifluoromethyl)phenyl]pyridinium-N,C 2 '}iridium(III) picolinate (abbreviated as: Ir(CF3ppy)2(pic)), bis[2-(4',6'-difluorophenyl)pyridinium-N,C 2'] Iridium (III) acetylacetonate (abbreviated as Fir (acac)) and other organometallic iridium complexes having a phenylpyridine compound having an electron withdrawing group as a ligand. Note that organometallic iridium complexes having a 4H-triazole skeleton are particularly preferred because of their high reliability and luminous efficiency. Examples of phosphorescent substances that emit green light include tris(4-methyl-6-phenylpyrimidinyl)iridium(III) (abbreviated as [Ir(mppm)3]), tris(4-tert-butyl-6-phenylpyrimidinyl)iridium(III) (abbreviated as [Ir(tBuppm)3]), (acetylacetonate)bis(6-methyl-4-phenylpyrimidinyl)iridium(III) (abbreviated as Ir(mppm)2(acac)), (acetylacetonate)bis(6-tert-butyl-4-phenylpyrimidinyl)iridium(III) (abbreviated as Ir(tBuppm)2(acac)), (acetylacetonate)bis(6-(2-norbornyl)-4-phenylpyrimidinyl)iridium(III) (abbreviated as Ir(nbppm)2(acac)), (acetylacetonate)bis[5-methyl-6- Organometallic iridium complexes having a pyrimidine skeleton, such as (2-methylphenyl)-4-phenylpyrimidinyl]iridium (III) (abbreviation: Ir(mpmppm)2(acac)), (acetylacetonate)bis(4,6-diphenylpyrimidinyl)iridium (III) (abbreviation: Ir(dppm)2(acac)); Organometallic iridium complexes having a pyrazine skeleton, such as (acetylacetonate)bis(3,5-dimethyl-2-phenylpyrazinyl)iridium (III) (abbreviation: Ir(mppr-Me)2(acac)), (acetylacetonate)bis(5-isopropyl-3-methyl-2-phenylpyrazinyl)iridium (III) (abbreviation: Ir(mppr-iPr)2(acac)); Organometallic iridium complexes having a pyrazine skeleton, such as tris(2-phenylpyridinyl)iridium (abbreviation: Ir(ppy)3), bis(2-phenylpyridinyl-N,C 2 ') iridium (III) acetylacetonate (abbreviated as Ir(ppy)2(acac)), bis(benzo[h]quinoline)iridium (III) acetylacetonate (abbreviated as Ir(bzq)2(acac)), tris(benzo[h]quinoline)iridium (III) (abbreviated as Ir(bzq)3), tris(2-phenylquinoline-N,C 2 '] iridium (III) (abbreviated as: Ir(pq)3), bis(2-phenylquinoline-N,C 2') iridium (III) acetylacetonate (abbreviated as: Ir (pq) 2 (acac)) and other organic metal iridium complexes having a pyridine skeleton; and tris (acetylacetonate) (monophenanthroline) terbium (III) (abbreviated as: Tb (acac) 3 (Phen)) and other rare earth metal complexes. In addition, organic metal iridium complexes having a pyrimidine skeleton are particularly preferred because of their very high reliability and luminous efficiency. Examples of phosphorescent materials that emit red light include: (diisobutyrylmethanato)bis[4,6-bis(3-methylphenyl)pyrimidinyl]iridium(III) (abbreviated as Ir(5mdppm)2(dibm)), bis[4,6-bis(3-methylphenyl)pyrimidinyl)(dipivaloylmethane)iridium(III) (abbreviated as Ir(5mdppm)2(dpm)), bis[4,6-di(naphthalene-1-yl)pyrimidinyl][dipivaloylmethane)iridium(III) (abbreviated as Ir(5mdppm)2(dpm)), )2(dpm)]) and other organic metal iridium complexes with a pyrimidine skeleton; (acetylacetonato)bis(2,3,5-triphenylpyrazine)iridium(III) (abbreviated as Ir(tppr)2(acac)), bis(2,3,5-triphenylpyrazine)(dipivaloylmethanone)iridium(III) (abbreviated as Ir(tppr)2(dpm)), (acetylacetonato)bis[2,3-bis(4-fluorophenyl)quinoxaline]iridium(III) (abbreviated as Ir(Fdpq)2(acac)) and other organic metal iridium complexes with a pyrazine skeleton; tris(1-phenylisoquinoline-N,C 2’ )iridium(III) (abbreviation: Ir(piq)3), bis(1-phenylisoquinoline-N,C 2’) iridium (III) acetylacetonate (abbreviation: Ir(piq)2(acac)) and other organometallic iridium complexes having a pyridine skeleton; platinum complexes such as 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum (II) (abbreviation: PtOEP); and rare earth metal complexes such as tris(1,3-diphenyl-1,3-propanedione)(monophenanthroline)europium (III) (abbreviation: Eu(DBM)3(Phen)), tris[1-(2-thenoyl)-3,3,3-trifluoroacetone](monophenanthroline)europium (III) (abbreviation: Eu(TTA)3(Phen)). Note that organometallic iridium complexes having a pyrazine skeleton are particularly preferred because they have very high reliability and luminous efficiency. In addition, since the organometallic iridium complex having a pyrazine skeleton can provide red light emission with good chromaticity, the color rendering of the white light emitting element can be improved by using the organometallic iridium complex in a white light emitting element. In addition, since the compound of one embodiment of the present invention having a structure in which a dibenzothiophenyl group, a dibenzofuranyl group or a carbazole group and a dibenzo[f,h]quinoxaline group are bonded through three or more arylene groups, it emits light and can be used as a luminescent center material.

[0763] As a material that can be used as a light-emitting substance, various substances can be selected in addition to the above-mentioned substances.

[0764] As a host material of the dispersed luminescent center substance, the heterocyclic compound of one embodiment of the present invention is preferably used.

[0765] Since the heterocyclic compound has a large band gap and a high triplet excitation energy level, the heterocyclic compound can be used as a main material for a luminescent center substance that not only disperses the fluorescence emitted in the visible region, but also disperses the luminescent center substance that presents high energy (such as a luminescent center substance that emits phosphorescence in the visible region, etc.). In particular, the compound can be used as a main material for a luminescent center substance that disperses the emission of blue phosphorescent light. Of course, the compound can also be used as a main material for a luminescent center substance that disperses the emission of fluorescence with a wavelength longer than that of blue light or a phosphorescent center substance that emits a wavelength longer than that of green light. Since the carrier transport property (especially electron transport property) of the compound is high, a light-emitting element with a low driving voltage can be realized.

[0766] When the heterocyclic compound is used as a host material, the guest material can be oriented due to its high orientation. Therefore, the light extraction efficiency is improved, which leads to an increase in external quantum efficiency. In addition, since the molecular weight of the heterocyclic compound is large, it has good thermal stability, which helps to prolong the service life of the light-emitting element.

[0767] In addition, it is also effective to use the compound as a material constituting a carrier transport layer (preferably an electron transport layer) adjacent to the light-emitting layer. Because the compound has a large band gap or a high triplet excitation energy level, even if the luminescent center material is a material that exhibits a large energy luminescence such as blue fluorescence or green to blue phosphorescence, the energy of the carriers recombined in the host material can be effectively moved to the luminescent center substance. Therefore, a light-emitting element with high luminescence efficiency can be manufactured. In addition, when the above-mentioned compound is used as a host material or a material constituting a carrier transport layer, as a luminescent center material, it is preferred to select a substance whose band gap between the HOMO energy level and the LUMO energy level is smaller than that of the compound or a substance whose singlet excitation energy level or triplet excitation energy level is lower than that of the compound, but is not limited thereto.

[0768] The following are examples of materials that can be used when the heterocyclic compound is not used as the host material.

[0769] Examples of materials having electron transport properties include metal complexes such as bis(10-hydroxybenzo[h]quinoline)beryllium(II) (abbreviated as BeBq2), bis(2-methyl-8-hydroxyquinoline)(4-phenylphenol)aluminum(III) (abbreviated as BAlq), bis(8-hydroxyquinoline)zinc(II) (abbreviated as Znq), bis[2-(2-benzoxazolyl)phenol]zinc(II) (abbreviated as ZnPBO), and bis[2-(2-benzothiazolyl)phenol]zinc(II) (abbreviated as ZnBTZ); and metal complexes such as 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated as PBD), and 3-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole. )-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (abbreviated as TAZ), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazol-2-yl]benzene (abbreviated as OXD-7), 9-[4-(5-phenyl-1,3,4-oxadiazol-2-yl)phenyl]-9H-carbazole (abbreviated as CO11), 2,2',2"-(1,3,5-benzenetriyl)tris(1-phenyl-1H-benzimidazole) (abbreviated as TPBI), 2-[3-(dibenzothiophen-4-yl)phenyl]-1-phenyl-1H-benzimidazole (abbreviated as mDBTBIm-II), etc.; 2- [3-(dibenzothiophene-4-yl)phenyl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTPDBq-II), 2-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II), 2-[3'-(9H-carbazole-9-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mCzBPDBq), 4,6-bis[3-(phenanthrene-9-yl)phenyl]pyrimidine (abbreviation: 4,6mPnP2Pm), 4,6-bis[3-(4-dibenzothiophene-1-yl)phenyl]pyrimidine (abbreviation: 4,6mDBTP2Pm-II) and the like Heterocyclic compounds having a diazine skeleton; and heterocyclic compounds having a pyridine skeleton, such as 3,5-bis[3-(9H-carbazole-9-yl)phenyl]pyridine (abbreviated as: 35DCzPPy), 1,3,5-tris[3-(3-pyridyl)phenyl]benzene (abbreviated as: TmPyPB). Among them, heterocyclic compounds having a diazine skeleton and heterocyclic compounds having a pyridine skeleton have high reliability, so they are preferred. In particular, heterocyclic compounds having a diazine (pyrimidine or pyrazine) skeleton have high electron transport properties, which helps to reduce the driving voltage. In addition, the compound having the above-mentioned benzothiophene pyrimidine skeleton is a material with relatively high electron transport properties and is classified as a material with electron transport properties.

[0770] Examples of materials having hole transport properties include 4,4'-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N'-bis(3-methylphenyl)-N,N'-diphenyl-[1,1'-biphenyl]-4,4'-diamine (abbreviation: TPD), 4,4'-bis[N-(spiro-9,9'-difluoren-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB), 4-phenyl-4'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: BPAFLP), 4-phenyl-3'-(9-phenylfluoren-9-yl)triphenylamine (abbreviation: mBPAFLP), 4-phenyl-4 '-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCBA1BP), 4,4'-diphenyl-4"-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCBBi1BP), 4-(1-naphthyl)-4'-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCBANB), 4,4'-di(1-naphthyl)-4"-(9-phenyl-9H-carbazole-3-yl)triphenylamine (abbreviated as: PCBNBB), 9,9-dimethyl-N-phenyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]fluorene-2-amine (abbreviated as: PCBAF), Compounds having an aromatic amine skeleton, such as N-phenyl-N-[4-(9-phenyl-9H-carbazol-3-yl)phenyl]spiro-9,9'-difluorene-2-amine (abbreviated as PCBASF); compounds having a carbazole skeleton, such as 1,3-bis(N-carbazolyl)benzene (abbreviated as mCP), 4,4'-di(N-carbazolyl)biphenyl (abbreviated as CBP), 3,6-bis(3,5-diphenylphenyl)-9-phenylcarbazole (abbreviated as CzTP), 3,3'-bis(9-phenyl-9H-carbazole) (abbreviated as PCCP); 4,4',4"-(benzene-1,3,5-triyl)tri(dibenzothiophene) (abbreviated as DBT3P- II), 2,8-diphenyl-4-[4-(9-phenyl-9H-fluorene-9-yl)phenyl]dibenzothiophene (abbreviated as: DBTFLP-III), 4-[4-(9-phenyl-9H-fluorene-9-yl)phenyl]-6-phenyldibenzothiophene (abbreviated as: DBTFLP-IV), and compounds having a thiophene skeleton; and 4,4',4"-(benzene-1,3,5-triyl)tri(dibenzofuran) (abbreviated as: DBF3P-II), 4-{3-[3-(9-phenyl-9H-fluorene-9-yl)phenyl]phenyl}dibenzofuran (abbreviated as: mmDBFFLBi-II), and the like. Among them, compounds having an aromatic amine skeleton and compounds having a carbazole skeleton are preferably used because these compounds have high reliability and high electron transport properties, which help to reduce the driving voltage.

[0771] In addition, when the luminescent center substance is a phosphorescent substance, it is preferred to select a substance whose triplet excitation energy level is higher than that of the phosphorescent substance as the host material, and when the luminescent center substance is a fluorescent substance, it is preferred to select a substance whose band gap is larger than that of the fluorescent substance as the host material. In addition to the host material and the phosphorescent substance, the luminescent layer may also contain a third substance. Note that this description does not exclude the case where the luminescent layer contains components other than the host material, the phosphorescent substance, and the third substance.

[0772] Here, in order to obtain a light-emitting element with higher luminous efficiency when using a phosphorescent material, energy transfer between the host material and the phosphorescent material is considered. Recombination of carriers occurs in both the host material and the phosphorescent material, so in order to improve the luminous efficiency, it is preferred to efficiently transfer energy from the host material to the phosphorescent material.

[0773] In this embodiment, a phosphorescent compound is used as a guest material. In the absorption spectrum of the phosphorescent compound, the absorption band that is considered to be most conducive to luminescence is located at and near the absorption wavelength corresponding to the direct transition from the ground state to the triplet excited state, which is on the longest wavelength side. Therefore, it is considered preferable that the emission spectrum (fluorescence spectrum and phosphorescence spectrum) of the host material overlaps with the absorption band on the longest wavelength side of the absorption spectrum of the phosphorescent compound.

[0774] For example, in most organometallic complexes, especially luminescent iridium complexes, a broad absorption band appears around 500nm to 600nm as the absorption band on the longest wavelength side. This absorption band is mainly derived from the triple MLCT (metal to ligand charge transfer) transition. However, it is believed that this absorption band also includes the triple π-π * The absorption of the transition and the single MLCT transition overlaps with each other to form a broad absorption band on the longest wavelength side of the absorption spectrum. Therefore, when an organometallic complex (especially an iridium complex) is used as a guest material, it is preferred that the broad absorption band on the longest wavelength side as described above overlaps most of the emission spectrum of the host material.

[0775] Here, energy transfer from the triplet excited state of the host material is first considered. According to the above discussion, in energy transfer from the triplet excited state, the phosphorescence spectrum of the host material and the absorption band on the longest wavelength side of the guest material are largely overlapped.

[0776] However, what becomes a problem at this time is the energy transfer from the singlet excited state of the host molecule. When the energy transfer from the singlet excited state is also efficiently performed in addition to the energy transfer from the triplet excited state, the host material is preferably designed in a manner that the fluorescence spectrum of the host material overlaps the absorption band on the longest wavelength side of the guest material in addition to the phosphorescence spectrum of the host material. In other words, when the host material is designed in a manner that the fluorescence spectrum of the host material is located at approximately the same position as the phosphorescence spectrum of the host material, energy transfer from both the singlet excited state and the triplet excited state of the host material can be efficiently performed.

[0777] However, in general, since the S1 energy level is very different from the T1 energy level (S1 energy level>T1 energy level), the emission wavelength of fluorescence is also very different from the emission wavelength of phosphorescence (emission wavelength of fluorescence<emission wavelength of phosphorescence). For example, in a light-emitting element using a phosphorescent compound, the commonly used 4,4'-di(N-carbazolyl)biphenyl (abbreviation: CBP) has a phosphorescence spectrum located near 500nm, while its fluorescence spectrum is located near 400nm, with a difference of about 100nm between the two. The above example also shows that it is extremely difficult to design a host material in such a way that the fluorescence spectrum of the host material is located at approximately the same position as the phosphorescence spectrum of the host material.

[0778] Furthermore, since fluorescence is light emitted at a higher energy level than phosphorescence, the T1 level of the host material at a fluorescence spectrum corresponding to a wavelength close to the absorption spectrum on the longest wavelength side of the guest material is lower than the T1 level of the guest material.

[0779] Therefore, when a phosphorescent substance is used as the luminescent center substance, the luminescent layer includes a third substance in addition to the host material and the luminescent center substance. The combination of the host material and the third substance forms an exciplex.

[0780] At this time, when the carriers (electrons and holes) recombine in the light-emitting layer, the host material and the third substance form an exciplex. The fluorescence spectrum of the exciplex is located on the longer wavelength side than the fluorescence spectrum of a single host material or the fluorescence spectrum of a single third substance. Therefore, in a state where the T1 energy level of the host material and the third substance remains higher than the T1 energy level of the guest material, the energy transfer from the singlet excited state can be maximized. In addition, because the T1 energy level and the S1 energy level of the exciplex are close to each other, the fluorescence spectrum and the phosphorescence spectrum are located at approximately the same position. As a result, both the fluorescence spectrum and the phosphorescence spectrum of the exciplex can overlap with the absorption equivalent to the migration of the guest molecule from the singlet ground state to the triplet excited state (the wide absorption band of the guest molecule located on the longest wavelength side in the absorption spectrum), thereby obtaining a light-emitting element with high energy transfer efficiency.

[0781] As the third substance, the above-mentioned materials that can be used as the main material or additive can be used. As long as they can form an exciplex, there is no particular limitation on the main material and the third substance, but a combination of a compound that easily receives electrons (a compound with electron transport properties) and a compound that easily receives holes (a compound with hole transport properties) is preferred.

[0782] In the case of using a compound with electron transport properties and a compound with hole transport properties to constitute the main material and the third substance, the carrier balance can be controlled by adjusting the mixing ratio of the compounds. Specifically, the ratio of the main material to the third substance (or additive) is preferably 1:9 to 9:1. Note that at this time, the light-emitting layer in which a luminescent center substance is dispersed can also be divided into two layers, and the mixing ratio of the main material and the third substance in the two layers can be different. By adopting the above structure, the carrier balance of the light-emitting element can be optimized, thereby improving the service life of the light-emitting element. In addition, one light-emitting layer can be used as a hole transport layer and the other light-emitting layer can be used as an electron transport layer.

[0783] When the light-emitting layer having the above structure is composed of a plurality of materials, it can be formed by co-deposition using a vacuum deposition method, an inkjet method using a solution of the materials, a spin coating method, a dip coating method, or the like.

[0784] The electron transport layer 114 is a layer containing a substance having electron transport properties. For example, the electron transport layer 114 is a layer composed of the following metal complexes having a quinoline skeleton or a benzoquinoline skeleton: tris(8-hydroxyquinoline)aluminum (abbreviated as: Alq), tris(4-methyl-8-hydroxyquinoline)aluminum (abbreviated as: Almq3), bis(10-hydroxybenzo[h]quinoline)beryllium (abbreviated as: BeBq2), bis(2-methyl-8-hydroxyquinoline)(4-phenylphenol)aluminum (abbreviated as: BAlq), etc. In addition, metal complexes having oxazole and thiazole ligands such as bis[2-(2-hydroxyphenyl)benzoxazole]zinc (abbreviated as: Zn(BOX)2) and bis[2-(2-hydroxyphenyl)benzothiazole]zinc (abbreviated as: Zn(BTZ)2) can also be used. In addition to metal complexes, 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (OXD-7), 3-(4-biphenyl)-4-phenyl-5-(4-tert-butylphenyl)-1,2,4-triazole (TAZ), bathophenanthroline (BPhen), bathocuproin (BCP), etc. can also be used. The substances described here are mainly those with an electron mobility of 10 -6 cm 2Note that any substance other than the above substances may be used as the electron transport layer as long as the substance has a higher electron transport property than a hole transport property.

[0785] In addition, the above heterocyclic compound can also be used as a material constituting the electron transport layer 114. Since the above heterocyclic compound has a large band gap and a high T1 energy level, it is possible to effectively prevent the excitation energy in the light-emitting layer from being transferred to the electron transport layer 114, and it is possible to suppress the reduction in luminous efficiency caused by the excitation energy transfer, thereby being able to obtain a light-emitting element with high luminous efficiency. In addition, the compound of one embodiment of the present invention has high carrier transport properties, and thus can provide a light-emitting element with a low driving voltage.

[0786] The electron transport layer may be a stack of two or more layers composed of any of the above-mentioned substances, and is not limited to a single layer.

[0787] In addition, a layer for controlling the movement of electron carriers may be provided between the electron transport layer and the light-emitting layer. This is a layer formed by adding a small amount of a substance with high electron capture properties to a material with high electron transport properties as described above, and the layer can adjust the carrier balance by suppressing the movement of electron carriers. This structure has a great effect on suppressing problems that occur when electrons pass through the light-emitting layer (for example, a reduction in the service life of the element).

[0788] The host material of the light-emitting layer and the material constituting the electron transport layer preferably have the same skeleton, which facilitates the movement of carriers and reduces the driving voltage. In addition, it is effective that the host material and the material constituting the electron transport layer are the same material.

[0789] In addition, an electron injection layer 115 can be provided between the electron transport layer 114 and the second electrode 102 in such a manner as to contact the second electrode 102. As the electron injection layer 115, lithium, calcium, lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF2), etc. can be used. In addition, a composite material of a substance having an electron transport property and a substance having an electron donating property to the substance (hereinafter referred to as an electron donating substance) can also be used. As the electron donating substance, for example, alkali metals, alkaline earth metals, their compounds and electron salts can be cited. As the electron salt, for example, an electron salt formed by adding electrons to calcium oxide-aluminum oxide at a high concentration can be cited. In addition, it is preferred to use such a composite material as the electron injection layer 115, so that electron injection from the second electrode 102 is efficiently performed. By adopting this structure, as a cathode, a conductive material can be used in addition to a material with a small work function.

[0790] As an electrode used as a cathode, any one of metals, alloys, conductive compounds, and mixtures thereof with a small work function (specifically, a work function of less than 3.8 eV) can be used. As specific examples of such cathode materials, elements belonging to Group 1 and Group 2 in the periodic table, namely lithium (Li), cesium (Cs), magnesium (Mg), calcium (Ca), and strontium (Sr), and alloys containing these metals (MgAg, AlLi), rare earth metals such as europium (Eu) and ytterbium (Yb), and alloys containing these rare earth metals, can be cited. However, by providing an electron injection layer between the second electrode 102 and the electron transport layer, various conductive materials such as Al, Ag, ITO, indium tin oxide containing silicon or silicon oxide, etc. can be used for the second electrode 102 regardless of the size of the work function. Films of these conductive materials can be formed by sputtering, inkjet, spin coating, etc.

[0791] As a method for forming the EL layer 103, various methods can be used regardless of whether it is a dry process or a wet process. For example, a vacuum evaporation method, an inkjet method, or a spin coating method can be used. In addition, a different film formation method can be used for each electrode or each layer.

[0792] The electrode may be formed by a wet method using a sol-gel method or a wet method using a paste of a metal material, or may be formed by a dry method such as a sputtering method or a vacuum deposition method.

[0793] Note that the structure of the EL layer provided between the first electrode 101 and the second electrode 102 is not limited to the above structure. However, it is preferable to provide a light-emitting region where holes and electrons recombine at a portion away from the first electrode 101 and the second electrode 102 in order to suppress quenching due to proximity of the light-emitting region to a metal used for an electrode or a carrier injection layer.

[0794] In addition, in order to suppress the energy transfer of excitons generated in the light-emitting layer, the hole transport layer and the electron transport layer directly in contact with the light-emitting layer, especially the carrier transport layer in contact with the side of the light-emitting region close to the light-emitting layer 113, are preferably composed of a material having a larger band gap than the light-emitting material constituting the light-emitting layer or the light-emitting center material contained in the light-emitting layer.

[0795] In the light-emitting element having such a structure, current flows due to the potential difference between the first electrode 101 and the second electrode 102, and holes and electrons recombine in the light-emitting layer 113 containing a highly luminescent substance to emit light. That is, a light-emitting region is formed in the light-emitting layer 113.

[0796] Light is extracted to the outside through one or both of the first electrode 101 and the second electrode 102. Therefore, one or both of the first electrode 101 and the second electrode 102 are light-transmitting electrodes. When only the first electrode 101 is a light-transmitting electrode, light is extracted from the substrate side through the first electrode 101. On the other hand, when only the second electrode 102 is a light-transmitting electrode, light is extracted from the side opposite to the substrate through the second electrode 102. When both the first electrode 101 and the second electrode 102 are light-transmitting electrodes, light is extracted from the substrate side and the side opposite to the substrate through the first electrode 101 and the second electrode 102.

[0797] Since the light-emitting element in this embodiment uses the compound of one embodiment of the present invention, the light-emitting element can have high external quantum efficiency. Since the heterocyclic compound of one embodiment of the present invention has high heat resistance, the light-emitting element has good thermal properties.

[0798] A substrate made of glass or plastic or the like can be used as a support to manufacture such a light-emitting element. By forming a plurality of such light-emitting elements on one substrate, a passive matrix light-emitting device can be manufactured. Alternatively, a transistor can be formed on a substrate made of glass or plastic or the like, and the light-emitting element can be manufactured on an electrode electrically connected to the transistor. Thus, an active matrix light-emitting device can be manufactured in which the transistor controls the driving of the light-emitting element. Note that there is no particular restriction on the structure of the transistor. Staggered TFTs or inversely staggered TFTs can be used. In addition, there is no particular restriction on the crystallinity of the semiconductor used for the TFT. In addition, the driving circuit formed in the TFT substrate can be formed by any one or both of an n-channel TFT and a p-channel TFT. As a material constituting the semiconductor layer of the TFT, any material can be used as long as it is a material exhibiting semiconductor properties, such as elements of Group 14 in the periodic table such as silicon (Si) and germanium (Ge), compounds such as gallium arsenide and indium phosphide, and oxides such as zinc oxide and tin oxide. As an oxide (oxide semiconductor) exhibiting semiconductor properties, a composite oxide of elements selected from indium, gallium, aluminum, zinc and tin can be used. For example, zinc oxide (ZnO), indium oxide containing zinc oxide (IZO: Indium Zinc Oxide), and an oxide composed of indium oxide, gallium oxide, and zinc oxide (IGZO: Indium Gallium Zinc Oxide) can be cited. In addition, an organic semiconductor can also be used. The structure of the semiconductor layer can be a crystalline structure or an amorphous structure. As specific examples of crystalline semiconductor layers, single crystal semiconductors, polycrystalline semiconductors, and microcrystalline semiconductors can be cited.

[0799] As described above, the heterocyclic compound of one embodiment of the present invention can be used for a light-emitting element.

[0800] This embodiment mode can be combined with any other embodiment mode as appropriate.

[0801] Implementation 4

[0802] In this embodiment, refer to Figure 1B One embodiment of a light-emitting element having a structure in which a plurality of light-emitting units are stacked (hereinafter also referred to as a stacked element) is described. The light-emitting element is a light-emitting element having a plurality of light-emitting units between a first electrode and a second electrode. Each light-emitting unit may have the same structure as the EL layer 103 described in Embodiment 2. That is, the light-emitting element described in Embodiment 2 is a light-emitting element having one light-emitting unit, whereas the light-emitting element described in this embodiment is a light-emitting element having a plurality of light-emitting units.

[0803] exist Figure 1B In the embodiment, a first light-emitting unit 511 and a second light-emitting unit 512 are stacked between the first electrode 501 and the second electrode 502, and a charge generation layer 513 is provided between the first light-emitting unit 511 and the second light-emitting unit 512. The first electrode 501 and the second electrode 502 correspond to the first electrode 101 and the second electrode 102 in Embodiment 2, respectively, and the materials described in Embodiment 2. In addition, the first light-emitting unit 511 and the second light-emitting unit 512 may be the same or different.

[0804] The charge generation layer 513 includes a composite material of an organic compound and a metal oxide. As the composite material of the organic compound and the metal oxide, the composite material that can be used for the hole injection layer shown in Embodiment 2 can be used. As the organic compound, any of various compounds such as aromatic amine compounds, carbazole compounds, aromatic hydrocarbons, and polymer compounds (oligomers, dendrimers, polymers, etc.) can be used. In addition, the organic compound preferably has 1×10 -6 cm 2 / Vs or more of the hole mobility. However, as long as the hole transport property is higher than the electron transport property, any substance other than these can be used. Because the composite material of the organic compound and the metal oxide has high carrier injection and carrier transport properties, low voltage drive and low current drive can be achieved. Note that in the light-emitting unit where the interface on the anode side contacts the charge generation layer, the charge generation layer can also have the function of a hole transport layer, so the hole transport layer may not be provided.

[0805] The charge generation layer 513 may also have a laminated structure of a layer containing a composite material of an organic compound and a metal oxide and a layer containing other materials. For example, a layer containing a composite material of an organic compound and a metal oxide and a layer containing a compound selected from electron-donating substances and a compound having high electron transport properties may be combined. In addition, a layer containing a composite material of an organic compound and a metal oxide may be combined with a transparent conductive film.

[0806] The charge generation layer 513 sandwiched between the first light-emitting unit 511 and the second light-emitting unit 512 may have any structure as long as it injects electrons into the light-emitting unit on one side and injects holes into the light-emitting unit on the other side when voltage is applied between the first electrode 501 and the second electrode 502. Figure 1B The charge generation layer 513 may be any layer that injects electrons into the first light-emitting unit 511 and injects holes into the second light-emitting unit 512 when a voltage is applied so that the potential of the first electrode is higher than the potential of the second electrode.

[0807] Although a light-emitting element having two light-emitting units is described in this embodiment, the present invention can be similarly applied to a light-emitting element having three or more light-emitting units stacked. As in the light-emitting element according to this embodiment, by separating a plurality of light-emitting units between a pair of electrodes by a charge generation layer, the light-emitting element can emit light at high brightness while maintaining a low current density, thereby realizing a light-emitting element with a longer service life. In addition, a light-emitting device that can be driven at a low voltage and has low power consumption can also be realized.

[0808] By making the emission colors of each light-emitting unit different from each other, the entire light-emitting element can emit light of a desired color. For example, by forming a light-emitting element having two light-emitting units in such a way that the emission colors of the first light-emitting unit and the emission colors of the second light-emitting unit are in a complementary color relationship, a light-emitting element that emits white light from the entire light-emitting element can be realized. Note that the term "complementary colors" refers to a color relationship in which achromatic colors are obtained when colors are mixed. That is, when light is obtained from a substance that emits light of colors in a complementary color relationship, white light emission can be obtained. In addition, the same is true for a light-emitting element having three light-emitting units. For example, when the emission color of the first light-emitting unit is red, the emission color of the second light-emitting unit is green, and the emission color of the third light-emitting unit is blue, white light can be emitted from the entire light-emitting element. In addition, by using a phosphorescent emission center substance in the emission layer of one light-emitting unit and a fluorescent emission center substance in the emission layer of another light-emitting unit, both fluorescence and phosphorescence can be efficiently emitted in one light-emitting element. For example, by obtaining red and green phosphorescence from one light-emitting unit and blue fluorescence from another light-emitting unit, white light with high luminous efficiency can be obtained.

[0809] Since the light-emitting element of this embodiment includes a compound having a structure in which a dibenzothiophenyl group, a dibenzofuranyl group or a carbazole group and a dibenzo[f,h]quinoxaline group are bonded through three or more arylene groups, the light-emitting element can have high luminous efficiency or low driving voltage. In addition, since light with high color purity derived from the luminescent center substance can be obtained from the light-emitting unit including the heterocyclic compound, it is easy to adjust the color of the entire light-emitting element.

[0810] This embodiment mode can be combined with any other embodiment mode as appropriate.

[0811] Implementation method 5

[0812] In this embodiment, a light-emitting device using a light-emitting element including a compound having a structure in which a dibenzothiophenyl group, a dibenzofuranyl group, or a carbazolyl group, and a dibenzo[f,h]quinoxaline group are bonded through three or more arylene groups is described.

[0813] In this embodiment, refer to Figure 2A and Figure 2B An example of a light-emitting device manufactured using a light-emitting element having a structure in which a dibenzothiophenyl group, a dibenzofuranyl group or a carbazole group and a dibenzo[f,h]quinoxaline group are bonded via three or more arylene groups is described. Figure 2A is a top view showing a light emitting device, Figure 2B is along Figure 2A 604 is a sealing substrate; 625 is a desiccant; 605 is a sealant; and 607 is a space surrounded by the sealant 605.

[0814] The guide wiring 608 is used to transmit the signal input to the source side driving circuit 601 and the gate side driving circuit 603, and receives the video signal, clock signal, start signal, reset signal, etc. from the FPC (flexible printed circuit) 609 used as an external input terminal. Although only the FPC is shown here, the FPC can also be installed with a printed wiring board (PWB). The light-emitting device in this specification includes not only the light-emitting device body, but also the light-emitting device installed with the FPC or PWB.

[0815] Next, refer to Figure 2B A cross-sectional structure is described. A driver circuit portion and a pixel portion are formed over an element substrate 610 , and a source-side driver circuit 601 as a driver circuit portion and one pixel in a pixel portion 602 are shown here.

[0816] As the source side driving circuit 601, a CMOS circuit combining an n-channel TFT 623 and a p-channel TFT 624 is formed. In addition, the driving circuit can also be formed using any of various circuits such as a CMOS circuit, a PMOS circuit, and an NMOS circuit. In this embodiment, although a driver-integrated type in which the driving circuit is formed on the substrate is shown, the driving circuit does not necessarily need to be formed on the substrate, and the driving circuit can also be formed outside instead of being formed on the substrate.

[0817] The pixel portion 602 is formed of a plurality of pixels including a switching TFT 611, a current control TFT 612, and a first electrode 613 electrically connected to the drain of the current control TFT 612. An insulator 614 is formed to cover the end of the first electrode 613, and a positive photosensitive resin film is used here.

[0818] In order to improve the coverage of the film formed on the insulator 614, the upper end or the lower end of the insulator 614 is formed into a curved surface having a curvature. For example, when a positive photosensitive acrylic resin is used as the material of the insulator 614, it is preferred that only the upper end of the insulator 614 includes a curved surface having a curvature radius (0.2 μm or more and 3 μm or less). As the insulator 614, either a negative photosensitive material or a positive photosensitive material can be used.

[0819] An EL layer 616 and a second electrode 617 are formed on the first electrode 613. As the material of the first electrode 613 serving as an anode, a material having a large work function is preferably used. For example, a single layer of an ITO film, an indium tin oxide film containing silicon, an indium oxide film containing 2 wt% or more and 20 wt% or less of zinc oxide, a titanium nitride film, a chromium film, a tungsten film, a Zn film, a Pt film, or the like, a stacked layer consisting of a titanium nitride film and a film containing aluminum as a main component, or a stacked layer consisting of three layers of a titanium nitride film, a film containing aluminum as a main component, and a titanium nitride film, etc. can be used. When a stacked layer structure is used, low wiring resistance, good ohmic contact, and a function as an anode can be obtained.

[0820] The EL layer 616 is formed by any of various methods such as a vapor deposition method using a vapor deposition mask, an inkjet method, and a spin coating method. The EL layer 616 includes a compound having a structure in which a dibenzothiophenyl group, a dibenzofuranyl group, or a carbazole group, and a dibenzo[f,h]quinoxaline group are bonded through three or more arylene groups. In addition, as other materials constituting the EL layer 616, low molecular weight compounds and high molecular weight compounds (including oligomers and dendrimers) can also be used.

[0821] As a material of the second electrode 617 formed on the EL layer 616 and serving as a cathode, a material having a small work function (Al, Mg, Li, Ca, or an alloy or compound thereof such as MgAg, MgIn, AlLi, etc.) is preferably used. When light generated in the EL layer 616 is transmitted through the second electrode 617, a stacked layer composed of a metal thin film and a transparent conductive film (ITO, indium oxide containing 2 wt% or more and 20 wt% or less of zinc oxide, indium tin oxide containing silicon, zinc oxide (ZnO), etc.) is preferably used as the second electrode 617.

[0822] In addition, a light-emitting element is formed by the first electrode 613, the EL layer 616, and the second electrode 617. The light-emitting element has the structure described in Embodiment 3. In the light-emitting device of this embodiment, the pixel portion is composed of a plurality of light-emitting elements, and may include both the light-emitting element having the structure described in Embodiment 3 and the light-emitting element having another structure.

[0823] The sealing substrate 604 and the element substrate 610 are bonded together by the sealant 605, and a light emitting element 618 is provided in a space 607 surrounded by the element substrate 610, the sealing substrate 604, and the sealant 605. The space 607 is filled with a filler. The filler may also be an inert gas (nitrogen, argon, etc.) or a resin and / or a dry material.

[0824] As the sealant 605, epoxy resin or glass powder is preferably used. These materials are preferably materials that do not allow moisture and oxygen to pass through as much as possible. As the sealing substrate 604, a glass substrate, a quartz substrate, a plastic substrate composed of fiber reinforced plastics (Fiber Reinforced Plastics: FRP), polyvinyl fluoride (PVF), polyester, or acrylic resin can be used.

[0825] As described above, a light-emitting device produced using a light-emitting element including a compound having a structure in which a dibenzothiophenyl group, a dibenzofuranyl group or a carbazolyl group and a dibenzo[f,h]quinoxaline group are bonded via three or more arylene groups can be obtained.

[0826] Figure 3A and Figure 3B An example of a light-emitting device that realizes full-color display by forming a light-emitting element that emits white light and providing a coloring layer (color filter) and the like is shown. Figure 3AShown are a substrate 1001, a base insulating film 1002, a gate insulating film 1003, gate electrodes 1006, 1007, 1008, a first interlayer insulating film 1020, a second interlayer insulating film 1021, a peripheral portion 1042, a pixel portion 1040, a driving circuit portion 1041, a first electrode 1024W, 1024R, 1024G, 1024B of the light-emitting element, a partition wall 1025, an EL layer 1028, a second electrode 1029 of the light-emitting element, a sealing substrate 1031, a sealant 1032, and the like.

[0827] exist Figure 3A In the embodiment, the coloring layers (red coloring layer 1034R, green coloring layer 1034G, blue coloring layer 1034B) are provided on the transparent substrate 1033. In addition, a black layer (black matrix) 1035 may be provided. The transparent substrate 1033 provided with the coloring layers and the black layer is aligned and fixed on the substrate 1001. In addition, the coloring layers and the black layer are covered by the covering layer 1036. Figure 3A In the embodiment, light emitted from some light-emitting layers does not pass through the coloring layers, while light emitted from other light-emitting layers passes through the coloring layers. Light that does not pass through the coloring layers becomes white light, and light that passes through any of the coloring layers becomes red light, blue light, and green light, so that an image can be displayed with pixels of four colors.

[0828] Figure 3B An example is shown in which a coloring layer (a red coloring layer 1034R, a green coloring layer 1034G, and a blue coloring layer 1034B) is formed between the gate insulating film 1003 and the first interlayer insulating film 1020. Figure 3B As shown, a coloring layer may be provided between the substrate 1001 and the sealing substrate 1031.

[0829] Although the light-emitting device has a structure in which light is extracted from the substrate 1001 side where the TFT is formed (bottom emission structure) described above, it may also have a structure in which light is extracted from the sealing substrate 1031 side (top emission structure). Figure 4 1001 is a cross-sectional view of a light-emitting device having a top emission structure. In this case, a substrate that does not transmit light can be used as the substrate 1001. The process until the connection electrode for connecting the TFT and the anode of the light-emitting element is formed is performed in the same manner as the process of the light-emitting device having a bottom emission structure. Then, a third interlayer insulating film 1037 is formed in a manner covering the electrode 1022. The insulating film may also have a planarization function. The third interlayer insulating film 1037 may be formed using the same material as the second interlayer insulating film, and may be formed using any other various materials.

[0830] Here, the first electrodes 1024W, 1024R, 1024G, and 1024B of the light-emitting elements are all used as anodes, but they can also be used as cathodes. Figure 4 In the case of a light-emitting device having a top emission structure shown in the figure, the first electrode is preferably a reflective electrode. The EL layer 1028 is formed to have the same structure as that described in Embodiment 2, and white light emission can be obtained.

[0831] exist Figure 3A and Figure 3B as well as Figure 4 In the embodiment of the present invention, a structure of an EL layer providing white light emission can be realized by using a plurality of light emitting layers or using a plurality of light emitting units, etc. Note that the structure providing white light emission is not limited to this.

[0832] In adopting Figure 4 In the case of the top emission structure shown, a sealing substrate 1031 provided with a coloring layer (red coloring layer 1034R, green coloring layer 1034G, blue coloring layer 1034B) can be used for sealing. The sealing substrate 1031 can also be provided with a black layer (black matrix) 1030 located between pixels. The coloring layer (red coloring layer 1034R, green coloring layer 1034G, blue coloring layer 1034B) and the black layer (black matrix) can also be covered by a cover layer. In addition, a light-transmitting substrate is used as the sealing substrate 1031.

[0833] Although an example of full-color display using four colors of red, green, blue, and white is shown here, it is not limited to this, and full-color display may be performed using three colors of red, green, and blue or four colors of red, green, blue, and yellow.

[0834] The light-emitting device in this embodiment uses the light-emitting element described in Embodiment 3 (a light-emitting element comprising a compound having a structure in which a dibenzothiophenyl group, a dibenzofuranyl group or a carbazolyl group, and a dibenzo[f,h]quinoxaline group are bonded via three or more arylene groups), so the light-emitting device can have good characteristics. Specifically, the compound having a structure in which a dibenzothiophenyl group, a dibenzofuranyl group or a carbazolyl group, and a dibenzo[f,h]quinoxaline group are bonded via three or more arylene groups has a large band gap and a high triplet excitation energy level, and can suppress energy transfer from the light-emitting substance, so that a light-emitting element having high luminous efficiency in a wide range of luminescent colors can be provided, and thus a light-emitting device having reduced power consumption and good color rendering can be realized. In addition, the compound having a structure in which a dibenzothiophenyl group, a dibenzofuranyl group or a carbazolyl group, and a dibenzo[f,h]quinoxaline group are bonded via three or more arylene groups has high carrier transport properties, and a light-emitting element with a low driving voltage can be obtained, thereby obtaining a light-emitting device with a low driving voltage. A compound having a structure in which a dibenzothiophenyl group, a dibenzofuranyl group or a carbazole group and a dibenzo[f,h]quinoxaline group are bonded via three or more arylene groups has good thermal properties and can thus realize a light-emitting device with high heat resistance.

[0835] The active matrix light emitting device has been described above, and the passive matrix light emitting device will be described below. Figure 5A and Figure 5B A passive matrix light-emitting device manufactured by applying one embodiment of the present invention is shown. Figure 5A is a perspective view showing a light emitting device, and Figure 5B is along Figure 5A The cross-sectional view of the line XY in the figure. Figure 5A and Figure 5BIn the embodiment, an EL layer 955 is provided between an electrode 952 and an electrode 956 on a substrate 951. The end of the electrode 952 is covered by an insulating layer 953. A partition wall layer 954 is provided on the insulating layer 953. The side walls of the partition wall layer 954 are inclined in such a manner that the interval between the two side walls gradually narrows toward the substrate surface. That is, the cross section of the partition wall layer 954 in the short side direction is a trapezoid, and the bottom side (the side facing the same direction as the surface direction of the insulating layer 953 and in contact with the insulating layer 953) is shorter than the top side (the side facing the same direction as the surface direction of the insulating layer 953 and not in contact with the insulating layer 953). By providing the partition wall layer 954 in this way, defects of the light-emitting element caused by static electricity or the like can be prevented. In the passive matrix light-emitting device, by using the light-emitting element described in Embodiment 3 driven at a low voltage (a light-emitting element comprising a compound having a structure in which a dibenzothiophenyl group, a dibenzofuranyl group or a carbazolyl group, and a dibenzo[f,h]quinoxaline group are bonded through three or more arylene groups), it is possible to drive with low power consumption. In addition, since the light-emitting element comprises a compound having a structure in which a dibenzothiophenyl group, a dibenzofuranyl group or a carbazolyl group, and a dibenzo[f,h]quinoxaline group are bonded through three or more arylene groups, the light-emitting device can have high heat resistance and luminous efficiency by including a light-emitting element having high heat resistance and luminous efficiency (the light-emitting element described in Embodiment 3).

[0836] Note that in this specification, etc., any substrate can be used to form a transistor or a light-emitting element. The type of substrate is not limited to a specific type. As an example of the substrate, a semiconductor substrate (for example, a single crystal substrate or a silicon substrate), an SOI substrate, a glass substrate, a quartz substrate, a plastic substrate, a metal substrate, a stainless steel substrate, a substrate with a stainless steel foil, a tungsten substrate, a substrate with a tungsten foil, a flexible substrate, a bonding film, a paper containing a fibrous material, or a substrate film can be used. As an example of a glass substrate, there are barium borosilicate glass, aluminoborosilicate glass, soda-lime glass, etc. As examples of flexible substrates, bonding films, substrate films, etc., plastic substrates represented by polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyether sulfone (PES), and polytetrafluoroethylene (PTFE) can be cited. In addition, for example, synthetic resins such as acrylic resins can be cited. In addition, polypropylene, polyester, polyvinyl fluoride, or polyvinyl chloride can be cited. In addition, polyamide, polyimide, aramid, epoxy resin, inorganic vapor-deposited film, paper, etc. can be cited. In particular, by using a semiconductor substrate, a single crystal substrate, or an SOI substrate, etc., it is possible to manufacture transistors with small deviations in characteristics, size, or shape, high current capacity, and small size. When the above transistors are used to form a circuit, low power consumption of the circuit or high integration of the circuit can be achieved.

[0837] In addition, a flexible substrate may be used as a substrate, and a transistor or a light-emitting element may be directly formed on the flexible substrate. Alternatively, a peeling layer may be provided between the substrate and the transistor. The peeling layer may be used when a part or all of a semiconductor device manufactured on the peeling layer is separated from the substrate and transferred to another substrate. In this case, the transistor may also be transferred to a substrate with low heat resistance or a flexible substrate. As the above-mentioned peeling layer, for example, a laminate of an inorganic film of a tungsten film and a silicon oxide film or an organic resin film such as polyimide formed on the substrate may be used.

[0838] That is, a transistor or a light-emitting element may be formed using one substrate, and then the transistor or light-emitting element may be transferred to another substrate. As the substrate to which the transistor or light-emitting element is transferred, not only the above-mentioned substrates that can form transistors may be used, but also paper substrates, cellophane substrates, aramid film substrates, polyimide film substrates, stone substrates, wood substrates, cloth substrates (including natural fibers (silk, cotton, linen), synthetic fibers (nylon, polyurethane, polyester), regenerated fibers (acetate, cuprammonium, rayon, regenerated polyester), etc.), leather substrates, and rubber substrates may be used. By using the above-mentioned substrates, transistors with good characteristics or transistors with low power consumption may be formed, devices that are not easily damaged or devices with high heat resistance may be manufactured, or lightweight or thinning may be achieved.

[0839] The above-mentioned light-emitting devices are capable of controlling each of a plurality of tiny light-emitting elements arranged in a matrix, so the light-emitting devices can be suitably used in display devices that display images.

[0840] This embodiment mode can be combined with any other embodiment mode as appropriate.

[0841] Implementation 6

[0842] In this embodiment, electronic devices including the light-emitting elements shown in Embodiment 3 are described. The light-emitting element described in Embodiment 3 includes a compound of one embodiment of the present invention having a structure in which a dibenzothiophenyl group, a dibenzofuranyl group or a carbazole group, and a dibenzo[f,h]quinoxaline group are bonded by three or more arylene groups, and is therefore a light-emitting element with reduced power consumption. As a result, the electronic devices described in this embodiment can be electronic devices including a display unit with reduced power consumption. In addition, since the light-emitting element described in Embodiment 3 is a light-emitting element with a lower driving voltage, an electronic device with a lower driving voltage can be realized. In addition, since the light-emitting element described in Embodiment 3 is a light-emitting element with good thermal properties, an electronic device with high heat resistance can be realized.

[0843] As electronic devices to which the above-mentioned light-emitting elements are applicable, for example, television devices (also referred to as television sets or television receivers), displays for computers, etc., cameras such as digital cameras and digital imagers, digital photo frames, mobile phones (also referred to as mobile phones, mobile phone devices), portable game consoles, portable information terminals, sound reproduction devices, large-scale game consoles such as pinball machines, etc., can be cited. Specific examples of these electronic devices are shown below.

[0844] Fig. 6A An example of a television device is shown. In the television device, a display unit 7103 is assembled in a frame 7101. In addition, the frame 7101 is supported by a bracket 7105. The display unit 7103 can display an image including light-emitting elements arranged in a matrix, which are the same as the light-emitting elements shown in Embodiment 3. Because the light-emitting elements all include compounds having a structure in which a dibenzothiophenyl group, a dibenzofuranyl group or a carbazole group, and a dibenzo[f,h]quinoxaline group are bonded through three or more arylene groups, they can have high luminous efficiency and low driving voltage. Therefore, the television device including the display unit 7103 composed of the light-emitting elements can have reduced power consumption and low driving voltage.

[0845] The television device can be operated by using an operation switch provided in the housing 7101 or a remote controller 7110 provided separately. Channels and volume can be controlled by using operation keys 7109 provided in the remote controller 7110, thereby controlling an image displayed on the display portion 7103. The remote controller 7110 may be provided with a display portion 7107 for displaying data output from the remote controller 7110.

[0846] In addition, the television device is equipped with a receiver, a modem, etc. General television broadcasts can be received by using the receiver. Furthermore, by connecting the television device to a wired or wireless communication network via a modem, one-way (from a sender to a receiver) or two-way (between a sender and a receiver or between receivers, etc.) information communication can be performed.

[0847] Figure 6B A computer is shown, which includes a main body 7201, a frame 7202, a display portion 7203, a keyboard 7204, an external connection port 7205, a pointing device 7206, and the like. In addition, the computer is manufactured by using the same light-emitting elements arranged in a matrix and used for the display portion 7203 as the light-emitting elements shown in Embodiment 3. Since the light-emitting elements each contain a compound of one embodiment of the present invention, they can have high luminous efficiency and low driving voltage. Therefore, a computer including a display portion 7203 composed of the light-emitting elements can have reduced power consumption and low driving voltage.

[0848] Figure 6CA portable game console is shown, which is composed of two housings, housing 7301 and housing 7302, and is connected to a connection portion 7303 in a manner that allows opening and closing. A display portion 7304 including light-emitting elements arranged in a matrix as in Embodiment 3 is incorporated in housing 7301, and a display portion 7305 is incorporated in housing 7302. Figure 6C The portable game console shown also includes a speaker portion 7306, a recording medium insertion portion 7307, an LED lamp 7308, an input unit (operation keys 7309, a connection terminal 7310, a sensor 7311 (a sensor having a function of measuring the following factors: force, displacement, position, speed, acceleration, angular velocity, number of rotations, distance, light, liquid, magnetism, temperature, chemical substance, sound, time, hardness, electric field, current, voltage, electricity, radiation, flow, humidity, slope, vibration, smell or infrared), a microphone 7312), etc. Of course, the structure of the portable game console is not limited to the above structure, as long as at least one or both of the display portion 7304 and the display portion 7305 uses a display portion including light-emitting elements arranged in a matrix as in embodiment 3, and a structure in which other auxiliary devices are appropriately provided can be adopted. Figure 6C The portable game machine shown has the functions of reading out a program or data stored in a recording medium to display it on a display unit and sharing information by wirelessly communicating with other portable game machines. Figure 6C The functions of the portable game console shown are not limited thereto, and various functions may be provided. Since the light-emitting element used in the display portion 7304 includes a compound of one embodiment of the present invention having a structure in which a dibenzothiophenyl group, a dibenzofuranyl group, or a carbazole group, and a dibenzo[f,h]quinoxaline group are bonded through three or more arylene groups, it can have high luminous efficiency, and thus the portable game console including the above-mentioned display portion 7304 can be a portable game console with reduced power consumption. Since the light-emitting elements used in the display portion 7304 each include a compound of one embodiment of the present invention and can be driven at a lower driving voltage, the portable game console can also be a portable game console with a low driving voltage.

[0849] Fig.6D An example of a mobile phone is shown. The mobile phone has a display portion 7402, an operation button 7403, an external connection port 7404, a speaker 7405, a microphone 7406, etc., which are assembled in a frame 7401. In addition, the mobile phone has a display portion 7402 including light-emitting elements arranged in a matrix shape, which are the same as the light-emitting elements shown in Embodiment 3. Since each of the light-emitting elements includes a compound of one embodiment of the present invention, it can have high luminous efficiency and low driving voltage. Therefore, the mobile phone including the display portion 7402 composed of the light-emitting element can have reduced power consumption and low driving voltage.

[0850] You can touch it with your finger etc. Fig.6D The user can input data into the mobile phone by touching the display portion 7402 of the mobile phone shown in the figure. In this case, operations such as making a call and writing an e-mail can be performed by touching the display portion 7402 with a finger or the like.

[0851] The display unit 7402 mainly has three screen modes. The first mode is a display mode mainly for displaying images. The second mode is an input mode mainly for inputting information such as text. The third mode is a display input mode that combines the two modes of display mode and input mode.

[0852] For example, when making a phone call or writing an e-mail, the text displayed on the screen can be input in a text input mode in which the display portion 7402 is mainly used to input text. In this case, it is preferred that a keyboard or number buttons are displayed on most of the screen of the display portion 7402.

[0853] By providing a detection device having a sensor for detecting inclination such as a gyroscope or an acceleration sensor inside the mobile phone, the orientation of the mobile phone (whether the mobile phone is placed vertically or horizontally for landscape mode or portrait mode) can be determined and the screen display of the display unit 7402 can be automatically switched.

[0854] The screen mode is switched by touching the display portion 7402 or operating the operation button 7403 of the frame body 7401. The screen mode can be switched according to the type of image displayed on the display portion 7402. For example, when the signal of the image displayed on the display portion is a signal of dynamic image data, the screen mode is switched to the display mode. When the signal is a signal of text data, the screen mode is switched to the input mode.

[0855] Furthermore, when no touch input is performed on the display portion 7402 for a certain period of time by detecting a signal detected by a light sensor of the display portion 7402 in the input mode, the screen mode may be controlled so as to switch from the input mode to the display mode.

[0856] The display portion 7402 can also be used as an image sensor. For example, by touching the display portion 7402 with a palm or a finger, an image of a palm print, a fingerprint, etc. can be captured, thereby enabling personal identification. In addition, by using a backlight or a sensing light source that emits near-infrared light in the display portion, images of finger veins, palm veins, etc. can also be captured.

[0857] Note that the structure described in this embodiment can be combined with any of the structures described in Embodiments 1 to 4 as appropriate.

[0858] As described above, the light-emitting device including the light-emitting element of the compound of one embodiment of the present invention described in Embodiment 3 has a wide range of applications, and thus the light-emitting device can be applied to electronic devices in various fields. By using this compound, electronic devices with reduced power consumption and low driving voltage can be obtained.

[0859] In addition, a light-emitting device including the compound of one embodiment of the present invention can be used in a light source device. Figure 7 One embodiment is described. Note that the light source device includes a light emitting element including a compound of one embodiment of the present invention as a light irradiation unit and includes at least an input / output terminal portion for supplying current to the light emitting element. In addition, the light emitting element is preferably isolated from the external atmosphere by sealing.

[0860] Figure 7 An example of a liquid crystal display device in which a light-emitting element including a compound of one embodiment of the present invention is used as a backlight is described. Figure 7 The liquid crystal display device shown includes a frame 901, a liquid crystal layer 902, a backlight 903, and a frame 904. The liquid crystal layer 902 is connected to a driver IC 905. The backlight 903 uses a light-emitting element containing the above compound, and current is supplied to the backlight 903 through a terminal 906.

[0861] By using the light-emitting element containing the above-mentioned compound in the backlight source of the liquid crystal display device, a backlight source with reduced power consumption can be obtained. In addition, by using the light-emitting element containing the above-mentioned compound, a surface-emitting lighting device can be manufactured, and a large-area surface-emitting lighting device can also be manufactured, so that the backlight source can be a large-area backlight source, and the liquid crystal display device can also be a large-area device. Furthermore, by using the backlight source of the light-emitting element containing the above-mentioned compound, the thickness of the light-emitting device can be made smaller than that of the existing light-emitting device, so the display device can also be made thinner.

[0862] Figure 8 An example in which a light-emitting element including a compound of one embodiment of the present invention is used in a desk lamp as a lighting device is described. Figure 8 The desk lamp shown includes a housing 2001 and a light source 2002 , and a light-emitting element including the above-mentioned heterocyclic compound is used as the light source 2002 .

[0863] Fig. 9An example of using a light-emitting element containing a compound of one embodiment of the present invention in an indoor lighting device 3001 is shown. The light-emitting element containing the above compound is a light-emitting element with reduced power consumption, so that a lighting device with reduced power consumption can be realized. In addition, because the light-emitting element containing the above compound can be large-area, the light-emitting element can be used in a lighting device with a large area. In addition, because the thickness of the light-emitting element containing the above compound is small, a thin lighting device can be manufactured. In addition, Fig. 9 An example in which a light-emitting element including a compound of one embodiment of the present invention is used in a display device 3002 is shown.

[0864] A light-emitting element including the compound of one embodiment of the present invention may be mounted on a windshield or an instrument panel of a car. Fig.10 One embodiment of using the light-emitting element containing the above heterocyclic compound for a windshield and an instrument panel of a car is shown. Display area 5000 to display area 5005 are all provided using the light-emitting element containing the above heterocyclic compound.

[0865] Display area 5000 and display area 5001 are display devices provided in the windshield of a car and equipped with a light-emitting element comprising the above-mentioned heterocyclic compound. By using a light-transmitting electrode to form a first electrode and a second electrode, the light-emitting element comprising the above-mentioned heterocyclic compound can be formed into a so-called perspective display device that can see the opposite side. Even if the perspective display device is provided in the windshield of a car, the field of view is not obstructed. In addition, in the case of providing a transistor for driving the light-emitting element, it is preferred to use a light-transmitting transistor, such as an organic transistor using an organic semiconductor material or a transistor using an oxide semiconductor.

[0866] The display area 5002 is a display device provided in the column part and equipped with a light-emitting element containing the above-mentioned heterocyclic compound. By displaying the image captured by the imaging unit provided in the vehicle body on the display area 5002, the field of view partially blocked by the column can be supplemented. Similarly, the display area 5003 provided in the instrument panel part can compensate for the field of view blocked by the vehicle body by displaying the image captured by the imaging unit provided outside the vehicle, thereby eliminating blind spots and improving safety. By displaying images to compensate for the parts that the driver cannot see, the driver can confirm safety more simply and comfortably.

[0867] Display area 5004 and display area 5005 can provide various information such as navigation data, speedometer, tachometer, driving distance, fueling amount, gear status, and air conditioning settings. The user can appropriately change the displayed content or layout. In addition, this information can also be displayed on display area 5000 to display area 5003. In addition, display area 5000 to display area 5005 can also be used as a lighting device.

[0868] By using a light-emitting element containing a compound having a structure in which a dibenzothiophenyl group, a dibenzofuranyl group or a carbazole group and a dibenzo[f,h]quinoxaline group are bonded through three or more arylene groups, a light-emitting device with good thermal properties can be realized. Therefore, even if the light-emitting device is placed in a high-temperature environment, the light-emitting device can be used thereafter, so the light-emitting device and the lighting device using the light-emitting element containing the above compound can be applied to a vehicle-mounted light-emitting device or a lighting device.

[0869] The compound of one embodiment of the present invention can be used in electronic devices such as organic thin-film solar cells. Specifically, since the compound has carrier transport properties, it can be used in a carrier transport layer or a carrier injection layer. The compound can be photoexcited, so it can be used in a power generation layer.

[0870] Example 1

[0871] "Synthesis Example 1"

[0872] In this synthesis example, a method for synthesizing the heterocyclic compound 2-[3″-(dibenzothiophene-4-yl)-3,1′:3′,1″-terphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBtTPDBq-II) (structural formula (2001)) described in Embodiment 1 and Embodiment 2 is described. The structural formula of 2mDBtTPDBq-II is shown below.

[0873] [Chemical formula 230]

[0874]

[0875] <Synthesis of 2-[3"-(dibenzothiophene-4-yl)-3,1':3',1"-terphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviated as: 2mDBtTPDBq-II)>

[0876] 1.5 g (3.3 mmol) of 2-(3'-bromo-3,1'-biphenyl-1-yl)dibenzo[f,h]quinoxaline, 1.1 g (3.5 mmol) of 3-(dibenzothiophene-4-yl)phenylboronic acid, 20 mg (65 μmol) of tri(2-methylphenyl)phosphine, 20 mL of toluene, 5 mL of ethanol, and 5 mL of potassium carbonate aqueous solution (2 mol / L) were poured into a 100 mL three-necked flask. The mixture in the flask was degassed under reduced pressure, and nitrogen was continuously passed through the system, and the mixture was heated to 80°C. After heating, 7.0 mg (30 μmol) of palladium (II) acetate was added, and the mixture was stirred at the same temperature for 12 hours. After stirring, the precipitated solid was collected by suction filtration, and the obtained solid was washed with water and ethanol, thereby obtaining 1.6 g of the target powder with a yield of 78%. The following formula (A-1) shows the synthesis scheme of this step.

[0877] [Chemical formula 231]

[0878]

[0879] The obtained solid was subjected to nuclear magnetic resonance spectroscopy ( 1 H NMR), and the analysis results are shown below.

[0880] 1 H NMR (chloroform-d, 500 MHz): δ = 7.38-7.45 (m, 2H), 7.59 (d, J = 4.5 Hz, 2H), 7.64-7.85 (m, 13H), 8.07 (s, 1H), 8.13 (s, 1H), 8.17-8.20 (m, 2H), 8.34 (d, J = 8.0 Hz, 1H), 8.64-8.67 (m, 3H), 9.24 (d, J = 8.0 Hz, 1H), 9.41 (d, J = 8.0 Hz, 1H), 9.47 (s, 1H)

[0881] Fig.11A and Fig. 11B Show 1 H NMR spectrum. Note that Fig. 11B yes Fig.11A The enlarged view of the range from 7.4 ppm to 9.6 ppm in FIG. 2 was obtained by confirming the target compound 2mDBtTPDBq-II from the measurement results.

[0882] 1.6 g of the obtained solid was purified by gradient sublimation method. In the sublimation purification, the solid was heated at 340° C. for 15 hours under the conditions of a pressure of 2.9 Pa and an argon flow rate of 15 mL / min, thereby obtaining 1.1 g of a solid with a recovery rate of 64%.

[0883] 《Physical properties of 2-[3"-(dibenzothiophene-4-yl)-3,1':3',1"-terphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBtTPDBq-II)》

[0884] Fig.12 and Fig.13 The absorption spectrum and emission spectrum of the toluene solution of 2mDBtTPDBq-II are shown respectively. Fig.14 and Fig.15 The absorption spectrum and emission spectrum of the thin film of 2mDBtTPDBq-II are shown respectively. The absorption spectrum is measured using an ultraviolet-visible spectrophotometer (manufactured by JASCO Corporation, Model V550). The emission spectrum is measured using a fluorescence spectrophotometer (manufactured by Hamamatsu Photonics Co., Ltd., Japan, FS920). The spectrum of the toluene solution is measured by placing a toluene solution of 2mDBtTPDBq-II in a quartz dish. The spectrum of the thin film of 2mDBtTPDBq-II is measured by manufacturing a sample by evaporating 2mDBtTPDBq-II and depositing it on a quartz substrate. Note that the absorption spectrum of the toluene solution shown in the figure is the absorption spectrum obtained by subtracting the absorption spectrum of the quartz dish and toluene from the measured spectrum, and the absorption spectrum of the thin film shown in the figure is the absorption spectrum obtained by subtracting the absorption spectrum of the quartz substrate from the measured spectrum.

[0885] Depend on Fig.12 It can be seen that the toluene solution of 2mDBtTPDBq-II exhibits absorption peaks near 374nm, 362nm, 333nm, and 321nm. Fig.13 It can be seen that the peak emission wavelengths are at 384nm and 403nm (excitation wavelength: 378nm). Fig.14 It can be seen that the film of 2mDBtTPDBq-II shows absorption peaks near 252nm, 294nm, 323nm, 338nm, 368nm and 384nm. Fig.15 It is known that the peak of the emission wavelength is around 421 nm (excitation wavelength: 321 nm). 2mDBtTPDBq-II was confirmed to emit blue-violet light. The compound of one embodiment of the present invention can be used as a host material of a light-emitting substance or a host material of a fluorescent substance in the visible region.

[0886] The phosphorescence of 2mDBtTPDBq-II was measured. In this measurement, a microscopic PL device LabRAM HR-PL (manufactured by Horiba, Ltd., Japan) was used, a He-Cd laser (325 nm) was used as the excitation light, a CCD detector was used as the detector, and the measurement temperature was set to 10 K. For the measurement, a thin film of the sample with a thickness of about 50 nm was formed on a quartz substrate, and another quartz substrate was bonded to the deposition surface of the quartz substrate in a nitrogen atmosphere. Fig.16 The obtained phosphorescence spectrum is shown. From this result, it can be seen that the peak on the shortest wavelength side in the phosphorescence spectrum of 2mDBtTPDBq-II exists at 514nm, which means that 2mDBtTPDBq-II has a high T1 level. It can be seen that the thin film of 2mDBtTPDBq-II is not easy to agglomerate in the atmosphere, has little morphological change, and has good film quality.

[0887] The redox reaction characteristics were investigated by cyclic voltammetry (CV) measurement. In the measurement, an electrochemical analyzer (manufactured by BAS Co., Ltd., model: ALS type 600A or 600C) was used. In the measurement solution, a solvent of dehydrated dimethylformamide (DMF) was used, and tetra-n-butylammonium perchlorate (n-Bu4NClO4) as a supporting electrolyte was dissolved at a concentration of 100 mmol / L, and the measurement object was also dissolved at a concentration of 2 mmol / L. In addition, a platinum electrode (manufactured by BAS Co., Ltd., PTE platinum electrode) was used as a working electrode, a platinum electrode (manufactured by BAS Co., Ltd., Pt counter electrode (5 cm) for VC-3) was used as an auxiliary electrode, and Ag / Ag was used as a reference electrode. + Electrode (manufactured by BAS Co., Ltd., RE7 non-aqueous solvent type reference electrode). The scanning speed was set to 0.1 V / sec in all measurements. As a result, the oxidation potential was -6.19 eV and the reduction potential was -2.94 eV. When the oxidation potential is regarded as the HOMO energy level and the reduction potential is regarded as the LUMO energy level, the band gap between the HOMO energy level and the LUMO energy level is estimated to be 3.25 eV, which means that 2mDBtTPDBq-II has a wider band gap.

[0888] Example 2

[0889] "Synthesis Example 2"

[0890] In this synthesis example, a method for synthesizing the heterocyclic compound 2-[3″-(dibenzothiophene-4-yl)-3,1′:4′,1″-terphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2DBtTPDBq) (structural formula (2002)) described in Embodiment 1 and Embodiment 2 is described. The structural formula of 2DBtTPDBq is shown below.

[0891] [Chemical formula 232]

[0892]

[0893] <Synthesis of 4-(4'-bromo-3,1'-biphenyl-1-yl)dibenzothiophene>

[0894] 3.0 g (9.8 mmol) of 3-(dibenzothiophene-4-yl)phenylboronic acid, 2.8 g (2.8 mmol) of 4-bromoiodobenzene, 0.15 g (0.49 mmol) of tri(2-methylphenyl)phosphine, 50 mL of toluene, 5 mL of ethanol, and 15 mL of potassium carbonate aqueous solution (2 mol / L) were poured into a 200 mL three-necked flask. The mixture was degassed under reduced pressure, and nitrogen was continuously flowed through the system. The mixture was heated to 80°C. Thereafter, 40 mg (0.18 mmol) of palladium (II) acetate was added and stirred at the same temperature for 10 hours. After stirring, the aqueous layer of the mixture was extracted three times with toluene, the extract and the organic layer were mixed, the mixture was washed with saturated brine, and dried with anhydrous magnesium sulfate. The obtained mixture was gravity filtered, and the obtained filtrate was concentrated to obtain a brown oil. The obtained oily substance was purified by silica gel column chromatography (developing solvent: hexane) and recrystallized from chloroform / hexane to obtain 2.5 g of the target substance as a white powder in a yield of 60%. The following (B-1) shows the synthesis scheme of this step.

[0895] [Chemical formula 233]

[0896]

[0897] <Synthesis of 3'-(dibenzothiophene-4-yl)-4,1'-biphenylboronic acid>

[0898] 2.8 g (6.7 mmol) of 4-(4'-bromo-3,1'-biphenyl-1-yl)dibenzothiophene synthesized by the steps shown in the above formula (B-1) was poured into a 300 mL three-necked flask. Nitrogen was continuously flowed through the system, and then 70 mL of dehydrated tetrahydrofuran was added. The solution was cooled to -78°C, and 5 mL (8.0 mmol) of n-butyl lithium hexane solution (1.6 mol / L) was dropped using a syringe, and after dropping, it was stirred at the same temperature for 1.5 hours. After stirring, 1 mL (8.9 mmol) of trimethyl borate was added at the same temperature, and the resulting solution was stirred at room temperature for 19 hours. After stirring, 30 mL of hydrochloric acid (1 mol / L) was added, and the aqueous layer of the mixture was extracted with ethyl acetate. The obtained extract and organic layer were mixed, the mixture was washed with sodium bicarbonate aqueous solution and saturated brine, and dried with anhydrous magnesium sulfate. The obtained mixture was gravity filtered, and the obtained filtrate was concentrated to obtain a light yellow solid. The obtained solid was washed with chloroform / hexane to obtain 1.9 g of a powder of the target compound at a yield of 75%. The following (B-2) shows the synthesis scheme of this step.

[0899] [Chemical formula 234]

[0900]

[0901] <Synthesis of 2-[3"-(dibenzothiophene-4-yl)-3,1':4',1"-terphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviated as: 2DBtTPDBq)>

[0902] 1.7 g (5.0 mmol) of 2-(3-chlorophenyl)dibenzo[f,h]quinoxaline, 1.9 g (5.0 mmol) of 3'-(dibenzothiophene-4-yl)-4,1'-biphenylboronic acid synthesized by the step shown in the above formula (B-2), 3.2 g (15 mmol) of tripotassium phosphate, 0.10 g (0.28 mmol) of di(1-adamantane)-n-butylphosphine, 2 mL of tert-butyl alcohol, and 25 mL of diethylene glycol dimethyl ether were poured into a 100 mL three-necked flask. The mixture was degassed under reduced pressure, and then nitrogen was continuously passed through the system. After the mixture was heated to 140°C, 30 mg (40 μmol) of [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) was added, and the mixture was stirred at the same temperature for 3.5 hours. After stirring, the precipitated solid was collected by suction filtration, and the obtained solid was washed with ethanol and water. The obtained solid was hot filtered with chloroform and the filtrate was concentrated to obtain 2.0 g of the target solid with a yield of 63%. The following (B-3) shows the synthesis scheme of this step.

[0903] [Chemical formula 235]

[0904]

[0905] The obtained solid was subjected to nuclear magnetic resonance spectroscopy ( 1 H NMR), and the analysis results are shown below.

[0906] 1 H NMR (tetrachloroethane-d2, 500 MHz): δ = 7.53-7.55 (m, 2H), 7.65-7.66 (m, 2H), 7.69 (t, J = 8.0 Hz, 1H), 7.76 (t, J = 8.0 Hz, 1H), 7.80-7.93 (m, 12H), 8.14 (s, 1H), 8.23-8.27 (m, 2H), 8.38 (d, J = 8.0 Hz, 1H), 8.70-8.72 (m, 3H), 9.33 (d, J = 8.0 Hz, 1H), 9.49 (d, J = 8.0 Hz, 1H), 9.53 (s, 1H)

[0907] Fig.17A and Fig. 17B Show1 H NMR spectrum. Note that Fig. 17B yes Fig.17A This is an enlarged view of the range from 7.4 ppm to 9.6 ppm in FIG. 2. The target substance 2DBtTPDBq was confirmed to be obtained from the measurement results.

[0908] 2.0 g of the obtained solid was purified by gradient sublimation. In the sublimation purification, the solid was heated at 340° C. for 14 hours under the conditions of a pressure of 2.9 Pa and an argon flow rate of 15 mL / min. After purification, 1.2 g of the target powder was obtained with a recovery rate of 60%.

[0909] 《Physical properties of 2-[3"-(dibenzothiophene-4-yl)-3,1':4',1"-terphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2DBtTPDBq)》

[0910] Fig.18 and Fig.19 The absorption spectrum and emission spectrum of a toluene solution of 2DBtTPDBq measured by the same measurement method as that of 2mDBtTPDBq-II are respectively shown. Fig. 20 and Fig.21 The absorption spectrum and emission spectrum of the thin film of 2DBtTPDBq measured by the same measurement method as that of 2mDBtTPDBq-II are respectively shown.

[0911] Depend on Fig.18 It can be seen that the toluene solution of 2DBtTPDBq exhibits absorption peaks near 361nm, 332nm and 282nm. Fig.19 It can be seen that the peak emission wavelengths are at 385nm and 405nm (excitation wavelength: 357nm). Fig. 20 It can be seen that the film of 2DBtTPDBq shows absorption peaks near 210nm, 249nm, 269nm, 293nm, 319nm, 339nm, 368nm and 384nm. Fig.21 It is known that the peak of the emission wavelength is around 423 nm (excitation wavelength: 385 nm). 2DBtTPDBq was confirmed to emit blue-violet light. The compound of one embodiment of the present invention can be used as a host material of a light-emitting substance or a host material of a fluorescent substance in the visible region.

[0912] The phosphorescence of 2DBtTPDBq was measured by the same method as 2mDBtTPDBq-II. Fig. 22The obtained phosphorescence spectrum is shown. From this result, it can be seen that the peak on the shortest wavelength side in the phosphorescence spectrum of 2DBtTPDBq exists at 517nm, which means that 2DBtTPDBq has a high T1 level. It can be seen that the thin film of 2DBtTPDBq is not easy to agglomerate in the atmosphere, has little morphological change, and has good film quality.

[0913] The redox reaction characteristics were investigated by cyclic voltammetry (CV) measurement. The measurement was performed by the same measurement method as 2mDBtTPDBq-II. As a result, no oxidation potential was observed, and the reduction potential was -2.99 eV.

[0914] Example 3

[0915] "Synthesis Example 3"

[0916] In this synthesis example, a method for synthesizing the heterocyclic compound 2-[4"-(dibenzothiophene-4-yl)-3,1':4',1"-terphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2DBtTPDBq-03) (structural formula (2003)) described in Embodiment 1 and Embodiment 2 is described. The structural formula of 2DBtTPDBq-03 is shown below.

[0917] [Chemical formula 236]

[0918]

[0919] <Synthesis of 4-(4-bromophenyl)dibenzothiophene>

[0920] 5.0 g (22 mmol) of dibenzothiophene-4-ylboronic acid, 6.2 g (22 mmol) of 4-bromoiodobenzene, 0.31 g (1.0 mmol) of tri(2-methylphenyl)phosphine, 110 mL of toluene, 10 mL of ethanol, and 30 mL of potassium carbonate aqueous solution (2 mol / L) were poured into a 300 mL three-necked flask. The mixture was degassed under reduced pressure, and then nitrogen was continuously flowed through the system. The resulting mixture was heated to 80°C. Then, 100 mg (0.44 mmol) of palladium (II) acetate was added and stirred for 11 hours. After stirring, the aqueous layer of the mixture was extracted with toluene, the extract and the organic layer were mixed, the mixture was washed with saturated brine, and dried with anhydrous magnesium sulfate. The mixture was gravity filtered, and the filtrate was concentrated to obtain a brown solid. The obtained solid was purified by silica gel column chromatography (developing solvent: hexane) and then recrystallized from hexane / chloroform to obtain 5.5 g of the target substance as a white solid in a yield of 74%. The following (C-1) shows the synthesis scheme of this step.

[0921] [Chemical formula 237]

[0922]

[0923] <Synthesis of 4-(dibenzothiophen-4-yl)phenylboronic acid>

[0924] 6.7 g (20 mmol) of 4-(4-bromophenyl)dibenzothiophene synthesized by the steps shown in the above formula (C-1) was poured into a 300 mL three-necked flask. Nitrogen was continuously flowed through the system, and then 200 mL of dehydrated tetrahydrofuran was added. The solution was cooled to -78 ° C, and 15 mL (24.0 mmol) of n-butyl lithium hexane solution (1.6 mol / L) was dropped using a syringe, and after dropping, it was stirred at the same temperature for 1.5 hours. After stirring, 3 mL (26.8 mmol) of trimethyl borate was added at the same temperature, and the resulting solution was stirred at room temperature for 20 hours. After stirring, 90 mL of hydrochloric acid (1 mol / L) was added, and the aqueous layer of the mixture was extracted with ethyl acetate. The obtained extract and the organic layer were mixed, and the mixture was washed with sodium bicarbonate aqueous solution and saturated brine, and dried with anhydrous magnesium sulfate. The obtained mixture was gravity filtered, and the obtained filtrate was concentrated to obtain a light yellow solid. The obtained solid was washed with chloroform / hexane to obtain 4.0 g of the target substance as a white solid at a yield of 77%. The following (C-2) shows the synthesis scheme of this step.

[0925] [Chemical formula 238]

[0926]

[0927] <Synthesis of 4-(4'-bromo-4,1'-biphenyl-1-yl)dibenzothiophene>

[0928] 3.7 g (12 mmol) of 4-(dibenzothiophene-4-yl)phenylboronic acid, 3.4 g (12 mmol) of 4-bromoiodobenzene, 0.20 g (0.65 mmol) of tri(2-methylphenyl)phosphine, 20 mL of potassium carbonate aqueous solution (2 mol / L), 60 mL of toluene, and 6 mL of ethanol synthesized by the steps shown in the above formula (C-1) were poured into a 200 mL three-necked flask. The mixture was degassed under reduced pressure, and then nitrogen was continuously flowed through the system. The resulting mixture was heated to 80°C, 30 mg (0.13 mmol) of palladium (II) acetate was added, and stirred at the same temperature for 7 hours. After stirring, the aqueous layer of the mixture was extracted with chloroform, the extract and the organic layer were mixed, the mixture was washed with saturated brine, and dried with anhydrous magnesium sulfate. The resulting mixture was gravity filtered, and the filtrate was concentrated to obtain a solid. The obtained solid was purified by silica gel column chromatography (developing solvent: chloroform) and then recrystallized from chloroform / hexane to obtain 3.3 g of the target solid in a yield of 66%. The following (C-3) shows the synthesis scheme of this step.

[0929] [Chemical formula 239]

[0930]

[0931] <Synthesis of 4'-(dibenzothiophene-4-yl)-4,1'-biphenylboronic acid>

[0932] 3.3 g (7.9 mmol) of 4-(4'-bromo-4,1'-biphenyl-1-yl) dibenzothiophene synthesized by the steps shown in the above formula (C-3) was poured into a 200 mL three-necked flask. Nitrogen was continuously flowed through the system, and then 80 mL of dehydrated tetrahydrofuran was added. The solution was cooled to -78°C, and 5.5 mL (8.8 mmol) of n-butyl lithium hexane solution (1.6 mol / L) was dropped using a syringe, and after dropping, it was stirred at the same temperature for 1.5 hours. After stirring, 1.1 mL (9.8 mmol) of trimethyl borate was added at the same temperature, and the resulting solution was stirred at room temperature for 20 hours. After stirring, 30 mL of hydrochloric acid (1 mol / L) was added, and the aqueous layer of the mixture was extracted with ethyl acetate. The obtained extract and the organic layer were mixed, the mixture was washed with sodium bicarbonate aqueous solution and saturated brine, and dried with anhydrous magnesium sulfate. The obtained mixture was gravity filtered, and the obtained filtrate was concentrated to obtain a pale yellow solid. The obtained solid was washed with chloroform / hexane to obtain 2.5 g of the target white solid at a yield of 83%. The following (C-4) shows the synthesis scheme of this step.

[0933] [Chemical formula 240]

[0934]

[0935] <Synthesis of 2-[4"-(dibenzothiophene-4-yl)-3,1':4',1"-terphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviated as: 2DBtTPDBq-03)>

[0936] 2.3 g (6.7 mmol) of 2-(3-chlorophenyl)dibenzo[f,h]quinoxaline, 2.5 g (6.5 mmol) of 4'-(dibenzothiophene-4-yl)-4,1'-biphenylboronic acid synthesized by the steps shown in the above formula (C-4), 4.1 g (20 mmol) of tripotassium phosphate, 0.12 g (0.34 mmol) of di(1-adamantane)-n-butylphosphine, 2 mL of tert-butyl alcohol, and 30 mL of diethylene glycol dimethyl ether were poured into a 200 mL three-necked flask. The mixture was degassed under reduced pressure, and then nitrogen was continuously flowed through the flask. After the mixture was heated to 140°C, 10 mg (65 μmol) of palladium (II) acetate was added and stirred at the same temperature for 5 hours. After stirring, the precipitated solid was collected by suction filtration, and the obtained solid was washed with water and ethanol. After washing, the obtained solid was filtered with chloroform while hot, and the filtrate was concentrated to obtain 2.0 g of a light black solid. The following (C-5) shows the synthesis scheme of this step.

[0937] [Chemical formula 241]

[0938]

[0939] The obtained solid was subjected to nuclear magnetic resonance spectroscopy ( 1 H NMR), and the analysis results are shown below.

[0940] 1 H NMR (chloroform-d, 500MHz): δ=7.49-7.51(m,2H), 7.57-7.63(m,2H), 7.73(t,J=8.0Hz,1H), 7.78-7.91(m,14H), 8.19-8 .23(m,2H), 8.35(d,J=8.0Hz,1H), 8.67-8.69(m,3H), 9.27(d,J=8.0Hz,1H), 9.47(d,J=8.0Hz,1H), 9.49(s,1H)

[0941] Fig.23A and Fig. 23B Show 1 H NMR spectrum. Note that Fig. 23B yes Fig.23AThe enlarged view of the range from 7.4ppm to 9.6ppm in FIG. 2 was obtained by confirming the target compound 2DBtTPDBq-03 from the measurement results.

[0942] 2.0 g of the obtained solid was purified by using a gradient sublimation method. In the sublimation purification, the solid was heated at 365° C. for 14.5 hours under the conditions of a pressure of 3.4 Pa and an argon flow rate of 15 mL / min. After purification, 1.4 g of powder was obtained with a recovery rate of 71%.

[0943] 《Physical properties of 2-[4"-(dibenzothiophene-4-yl)-3,1':4',1"-terphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2DBtTPDBq-03)》

[0944] Fig.24 and Fig.25 The absorption spectrum and emission spectrum of the toluene solution of 2DBtTPDBq-03 measured by the same measurement method as that of 2mDBtTPDBq-II are respectively shown. Fig.26 and Fig. 27 The absorption spectrum and emission spectrum of the thin film of 2DBtTPDBq-03 measured by the same measurement method as that of 2mDBtTPDBq-II are respectively shown.

[0945] Depend on Fig.24 It can be seen that the toluene solution of 2DBtTPDBq-03 exhibits absorption peaks near 294nm, 304nm, 361nm and 374nm. Fig.25 It can be seen that the peak emission wavelengths are at 378nm and 405nm (excitation wavelength: 360nm). Fig.26 It can be seen that the film of 2DBtTPDBq-03 exhibits absorption peaks near 242nm, 266nm, 299nm, 314nm, 346nm, 368nm and 383nm. Fig. 27 It is known that the peak of the emission wavelength is around 436 nm (excitation wavelength: 383 nm). 2DBtTPDBq-03 was confirmed to emit blue-violet light. The compound of one embodiment of the present invention can be used as a host material of a light-emitting substance or a host material of a fluorescent substance in the visible region.

[0946] The phosphorescence of 2DBtTPDBq-03 was measured using the same method as 2mDBtTPDBq-II. Fig.28The obtained phosphorescence spectrum is shown. From the results, it can be seen that the peak on the shortest wavelength side in the phosphorescence spectrum of 2DBtTPDBq-03 exists at 545nm, which means that 2DBtTPDBq-03 has a high T1 level. It can be seen that the thin film of 2DBtTPDBq-03 is not easy to agglomerate in the atmosphere, has little morphological change, and has good film quality.

[0947] The redox reaction characteristics were investigated by cyclic voltammetry (CV) measurement. The measurement was performed using the same measurement method as 2mDBtTPDBq-II. As a result, the oxidation potential was -6.15 eV and the reduction potential was -2.95 eV. When the oxidation potential is regarded as the HOMO energy level and the reduction potential is regarded as the LUMO energy level, the band gap between the HOMO energy level and the LUMO energy level is estimated to be 3.20 eV, which means that 2DBtTPDBq-03 has a wider band gap.

[0948] Example 4

[0949] "Synthesis Example 4"

[0950] In this synthesis example, a method for synthesizing the heterocyclic compound 2-[4"-(dibenzothiophene-4-yl)-4,1':3',1"-terphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2DBtTPDBq-02) (structural formula (2004)) described in Embodiment 1 and Embodiment 2 is described. The structural formula of 2DBtTPDBq-02 is shown below.

[0951] [Chemical formula 242]

[0952]

[0953] <Synthesis of 2-[4"-(dibenzothiophene-4-yl)-4,1':3',1"-terphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviated as: 2DBtTPDBq-02)>

[0954] 1.2 g (3.5 mmol) of 2-(4-chlorophenyl)dibenzo[f,h]quinoxaline, 1.1 g (3.4 mmol) of 4'-(dibenzothiophene-4-yl)-4,1'-biphenylboronic acid, the synthesis method of which is described in the above example, 2.1 g (9.9 mmol) of tripotassium phosphate, 80 mg (0.22 mmol) of di(1-adamantane)-n-butylphosphine, 1 mL of tert-butyl alcohol, and 15 mL of diethylene glycol dimethyl ether were poured into a 200 mL three-necked flask. The mixture was degassed under reduced pressure, and then nitrogen was continuously passed through the system. Then, the mixture was heated to 140°C, 20 mg (80 μmol) of palladium (II) acetate was added, and then stirred for 7 hours. After stirring, the mixture was cooled to room temperature, and then 10 mL of diethylene glycol dimethyl ether was added. Then, 30 mg (40 μmol) of [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium (II) was added, and the mixture was stirred at 140°C for 5.5 hours. After stirring, the precipitated solid was collected by suction filtration and washed with water and ethanol. The obtained solid was hot filtered using chloroform and the filtrate was concentrated to obtain 1.3 g of the target solid with a yield of 58%. The following (D-1) shows the synthesis scheme of this step.

[0955] [Chemical formula 243]

[0956]

[0957] The obtained solid was subjected to nuclear magnetic resonance spectroscopy ( 1 H NMR), and the analysis results are shown below.

[0958] 1 H NMR (tetrachloroethane-d2, 500 MHz): δ = 7.50-7.54 (m, 2H), 7.61-7.68 (m, 3H), 7.77-7.93 (m, 11H), 7.99 (d, J = 8.0 Hz, 2H), 8.06 (s, 1H), 8.21-8.25 (m, 2H), 8.52 (d, J = 8.0 Hz, 2H), 8.70 (d, J = 8.0 Hz, 2H), 9.26 (d, J = 8.0 Hz, 1H), 9.47 (d, J = 8.0 Hz, 1H), 9.50 (s, 1H)

[0959] Fig.29A and Fig.29B Show 1 H NMR spectrum. Fig.29B yes Fig.29A The enlarged view of the range from 7.4ppm to 9.6ppm in FIG. 2 was obtained by confirming the target compound 2DBtTPDBq-02 from the measurement results.

[0960] The obtained solid of 1.3 g was purified by gradient sublimation method. In the sublimation purification, the solid was heated at 350° C. for 14.5 hours under the conditions of pressure of 2.9 Pa and argon flow rate of 15 mL / min. After purification, 0.75 g of the target solid was obtained with a recovery rate of 60%.

[0961] 《Physical properties of 2-[4"-(dibenzothiophene-4-yl)-4,1':3',1"-terphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2DBtTPDBq-02)》

[0962] Fig.30 and Fig.31 The absorption spectrum and emission spectrum of the toluene solution of 2DBtTPDBq-02 measured by the same measurement method as that of 2mDBtTPDBq-II are respectively shown. Fig.32 and Fig.33 The absorption spectrum and emission spectrum of the thin film of 2DBtTPDBq-02 measured by the same measurement method as that of 2mDBtTPDBq-II are respectively shown.

[0963] Depend on Fig.30 It can be seen that the toluene solution of 2DBtTPDBq-02 exhibits absorption peaks near 281nm, 311nm, 368nm, and 378nm. Fig.31 It can be seen that the peak emission wavelengths are at 386nm and 405nm (excitation wavelength: 360nm). Fig.32 It can be seen that the film of 2DBtTPDBq-02 shows absorption peaks near 209nm, 242nm, 263nm, 272nm, 316nm, 338nm, 377nm and 389nm. Fig.33 It is known that the peaks of the emission wavelength are around 450 nm and 439 nm (excitation wavelength: 439 nm). 2DBtTPDBq-02 was confirmed to emit blue light. The compound of one embodiment of the present invention can be used as a host material of a luminescent substance or a host material of a fluorescent substance in the visible region.

[0964] The phosphorescence of 2DBtTPDBq-02 was measured using the same method as 2mDBtTPDBq-II. Fig.34 The obtained phosphorescence spectrum is shown. From this result, it can be seen that the peak on the shortest wavelength side in the phosphorescence spectrum of 2DBtTPDBq-02 exists at 545nm, which means that 2DBtTPDBq-02 has a high T1 level. It can be seen that the thin film of 2DBtTPDBq-02 is not easy to agglomerate in the atmosphere, has little morphological change, and has good film quality.

[0965] The redox reaction characteristics were investigated by cyclic voltammetry (CV) measurement. The measurement was performed using the same measurement method as 2mDBtTPDBq-II. As a result, the oxidation potential was -6.15 eV and the reduction potential was -2.94 eV. When the oxidation potential is regarded as the HOMO energy level and the reduction potential is regarded as the LUMO energy level, the band gap between the HOMO energy level and the LUMO energy level is estimated to be 3.19 eV, which means that 2DBtTPDBq-02 has a wider band gap.

[0966] Example 5

[0967] "Synthesis Example 5"

[0968] In this synthesis example, a method for synthesizing the heterocyclic compound 2-[4"-(dibenzothiophene-4-yl)-3,1':3',1"-terphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2DBtTPDBq-04) (structural formula (2005)) described in Embodiment 1 and Embodiment 2 is described. The structural formula of 2DBtTPDBq-04 is shown below.

[0969] [Chemical formula 244]

[0970]

[0971] <Synthesis of 4-(3'-bromo-4,1'-biphenyl-1-yl)dibenzothiophene>

[0972] 3.9 g (13 mmol) of 4-(dibenzothiophene-4-yl)phenylboronic acid, the synthesis method of which is described in the above example, 3.6 g (13 mmol) of 3-bromoiodobenzene, 0.20 g (0.65 mmol) of tri(2-methylphenyl)phosphine, 20 mL of potassium carbonate aqueous solution (2 mol / L), 64 mL of toluene, and 6 mL of ethanol were poured into a 200 mL three-necked flask. The mixture was degassed under reduced pressure, and then nitrogen was continuously passed through the system. The resulting mixture was heated to 80°C. Thereafter, 30 mg (0.13 mmol) of palladium (II) acetate was added and stirred at the same temperature for 6 hours. After stirring, the aqueous layer of the mixture was extracted with chloroform, the extract and the organic layer were mixed, the mixture was washed with saturated brine, and dried with anhydrous magnesium sulfate. The resulting mixture was gravity filtered, and the filtrate was concentrated to obtain a solid. The obtained solid was purified by silica gel column chromatography (developing solvent: chloroform) and then recrystallized from chloroform / hexane to obtain 3.8 g of the target solid in a yield of 71%. The following (E-1) shows the synthesis scheme of this step.

[0973] [Chemical formula 245]

[0974]

[0975] <Synthesis of 4'-(dibenzothiophene-4-yl)-3,1'-biphenylboronic acid>

[0976] 3.7 g (8.9 mmol) of 4-(3'-bromo-4,1'-biphenyl-1-yl) dibenzothiophene synthesized by the steps shown in the above formula (E-1) was poured into a 200 mL three-necked flask. Nitrogen was continuously flowed through the system, and then 90 mL of dehydrated tetrahydrofuran was added. The solution was cooled to -78°C, and 6.1 mL (8.9 mmol) of n-butyl lithium hexane solution (1.6 mol / L) was dropped using a syringe, and after dropping, it was stirred at the same temperature for 1.5 hours. After stirring, 1.2 mL (11 mmol) of trimethyl borate was added at the same temperature, and the resulting solution was stirred at room temperature for 20 hours. After stirring, 30 mL of hydrochloric acid (1 mol / L) was added, and the aqueous layer of the mixture was extracted with ethyl acetate. The obtained extract and organic layer were mixed, the mixture was washed with sodium bicarbonate aqueous solution and saturated brine, and dried with anhydrous magnesium sulfate. The obtained mixture was gravity filtered, and the obtained filtrate was concentrated to obtain a pale yellow solid. The obtained solid was washed with chloroform / hexane to obtain 2.6 g of the target substance as a white solid in a yield of 78%. The following (E-2) shows the synthesis scheme of this step.

[0977] [Chemical formula 246]

[0978]

[0979] <Synthesis of 2-[4"-(dibenzothiophene-4-yl)-3,1':3',1"-terphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviated as: 2DBtTPDBq-04)>

[0980] 1.2 g (3.5 mmol) of 2-(3-chlorophenyl)dibenzo[f,h]quinoxaline, 1.1 g (3.4 mmol) of 4'-(dibenzothiophene-4-yl)-3,1'-biphenylboronic acid synthesized by the step shown in the above formula (E-2), 2.1 g (9.9 mmol) of tripotassium phosphate, 70 mg (0.20 mmol) of di(1-adamantane)-n-butylphosphine, 1 mL (11 mmol) of tert-butyl alcohol, and 15 mL of diethylene glycol dimethyl ether were poured into a 200 mL three-necked flask. The mixture was degassed under reduced pressure, and then nitrogen was continuously passed through the system. Then, 30 mg (40 μmol) of [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium(II) was added to the mixture, and the mixture was stirred at 140°C for 4.5 hours. After stirring, the precipitated solid was collected by suction filtration and washed with water and ethanol to obtain a solid. The obtained solid was hot filtered using chloroform and the filtrate was concentrated to obtain 1.3 g of the target solid with a yield of 59%. The following (E-3) shows the synthesis scheme of this step.

[0981] [Chemical formula 247]

[0982]

[0983] The obtained solid was subjected to nuclear magnetic resonance spectroscopy ( 1 H NMR), and the analysis results are shown below.

[0984] 1 H NMR (chloroform-d, 500MHz): δ=7.47-7.49(m,2H), 7.56-7.61(m,2H), 7.66(t,J=8.0Hz,1H), 7.72-7.88(m,13H), 8.05(s,1H), 8.18-8.22(m,2H), 8.37(d,J=8.0Hz,1H), 8.66-8.68(m,3H), 9.27(d,J=8.0Hz,1H), 9.46(d,J=8.0Hz,1H), 9.49(s,1H)

[0985] Fig.35A and Fig.35B Show 1 H NMR spectrum. Note that Fig.35B yes Fig.35A The enlarged view of the range from 7.4ppm to 9.6ppm in FIG. 2 was obtained, and the target compound 2DBtTPDBq-04 was confirmed from the measurement results.

[0986] The obtained solid of 1.3 g was purified by gradient sublimation method. In the sublimation purification, the solid was heated at 335° C. for 14.5 hours under the conditions of pressure of 2.9 Pa and argon flow rate of 15 mL / min. After purification, 0.96 g of the target solid was obtained with a recovery rate of 74%.

[0987] 《Physical properties of 2-[4"-(dibenzothiophene-4-yl)-3,1':3',1"-terphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2DBtTPDBq-04)》

[0988] Fig.36 and Fig.37 The absorption spectrum and emission spectrum of the toluene solution of 2DBtTPDBq-04 measured by the same measurement method as that of 2mDBtTPDBq-II are respectively shown. Fig.38 and Fig.39 The absorption spectrum and emission spectrum of the thin film of 2DBtTPDBq-04 measured by the same measurement method as that of 2mDBtTPDBq-II are respectively shown.

[0989] Depend on Fig.36 It can be seen that the toluene solution of 2DBtTPDBq-04 exhibits absorption peaks near 280nm, 332nm, 361nm and 375nm. Fig.37 It can be seen that the peak emission wavelengths are at 385nm and 404nm (excitation wavelength: 360nm). Fig.38 It can be seen that the 2DBtTPDBq-04 film shows absorption peaks near 210nm, 262nm, 296nm, 315nm, 341nm, 368nm and 384nm. Fig.39 It is known that the peaks of the emission wavelength are around 429 nm and 446 nm (excitation wavelength: 385 nm). 2DBtTPDBq-04 was confirmed to emit blue-violet light. The compound of one embodiment of the present invention can be used as a host material of a luminescent substance or a host material of a fluorescent substance in the visible region.

[0990] The phosphorescence of 2DBtTPDBq-04 was measured using the same method as 2mDBtTPDBq-II. Fig.40 The obtained phosphorescence spectrum is shown. From this result, it can be seen that the peak on the shortest wavelength side in the phosphorescence spectrum of 2DBtTPDBq-04 exists at 518nm, which means that 2DBtTPDBq-04 has a high T1 level. It can be seen that the thin film of 2DBtTPDBq-04 is not easy to agglomerate in the atmosphere, has little morphological change, and has good film quality.

[0991] The redox reaction characteristics were investigated by cyclic voltammetry (CV) measurement. The measurement was performed by the same measurement method as 2mDBtTPDBq-II. As a result, the oxidation potential was -6.16 eV and the reduction potential was -2.94 eV. When the oxidation potential is regarded as the HOMO energy level and the reduction potential is regarded as the LUMO energy level, the band gap between the HOMO energy level and the LUMO energy level is estimated to be 3.22 eV.

[0992] Example 6

[0993] "Synthesis Example 6"

[0994] In this synthesis example, a method for synthesizing the heterocyclic compound 2-[3"'-(dibenzothiophene-4-yl)-3,1':3',1":3",1"'-quaterphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBtQPDBq-II) (structural formula (2006)) described in Embodiment 1 and Embodiment 2 is described. The structural formula of 2mDBtQPDBq-II is shown below.

[0995] [Chemical formula 248]

[0996]

[0997] <Synthesis of 4-(3'-bromo-3,1'-biphenyl-1-yl)dibenzothiophene>

[0998] 3.0 g (9.8 mmol) of 3-(dibenzothiophene-4-yl)phenylboronic acid, 2.8 g (9.9 mmol) of 3-bromoiodobenzene, 0.16 g (0.53 mmol) of tri(2-methylphenyl)phosphine, 15 mL of potassium carbonate aqueous solution (2 mol / L), 50 mL of toluene, and 5 mL of ethanol were poured into a 200 mL three-necked flask. Then, the mixture was degassed under reduced pressure, and nitrogen was continuously flowed through the system. The mixture was heated to 80°C. After that, 40 mg (0.18 mmol) of palladium (II) acetate was added, and the mixture was stirred at the same temperature for 9 hours. After stirring, the aqueous layer of the obtained mixture was extracted with toluene, the extract and the organic layer were mixed, washed with saturated brine, and dried with anhydrous magnesium sulfate. The mixture was gravity filtered, and the filtrate was concentrated to obtain 5 g of brown oil. The obtained oily substance was purified by high performance liquid chromatography (developing solvent: chloroform) to obtain 2.6 g of the target compound as a colorless transparent oily substance in a yield of 64%. The following (F-1) shows the synthesis scheme of this step.

[0999] [Chemical formula 249]

[1000]

[1001] <Synthesis of 2-[3"'-(dibenzothiophene-4-yl)-3,1':3',1":3",1"'-quaterphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviated as: 2mDBtQPDBq-II)>

[1002] 2.6 g (6.3 mmol) of 4-(3'-bromo-3,1'-biphenyl-1-yl)dibenzothiophene, 3.2 g (6.2 mmol) of 2-[3'-(2-dibenzo[f,h]quinoxalinyl)-1,1'-biphenyl-3-yl]-4,4,5,5-tetramethyl-1,3,2-dioxaborolane, 0.10 g (0.33 mmol) of tri(2-methylphenyl)phosphine, 30 mL of toluene, 3 mL of ethanol, and 10 mL of potassium carbonate aqueous solution (2 mol / L) were poured into a 100 mL three-necked flask. After the mixture was degassed under reduced pressure, nitrogen was continuously passed through the system. Then, the mixture was heated to 80° C., 14 mg (60 μmol) of palladium (II) acetate was added, and then stirred for 3 hours. After stirring, the precipitated solid was collected by suction filtration, washed with water and ethanol, and recrystallized with toluene to obtain a solid of the target substance at a yield of 80%. The following (F-2) shows the synthesis scheme of this step.

[1003] [Chemical formula 250]

[1004]

[1005] The obtained solid was subjected to nuclear magnetic resonance spectroscopy ( 1 H NMR), and the analysis results are shown below.

[1006] 1 H NMR (tetrachloroethane-d2, 500 MHz): δ = 7.46-7.51 (m, 2H), 7.59-7.69 (m, 5H), 7.73-7.91 (m, 13H), 8.11 (d, J = 8.0 Hz, 2H), 8.15 (s, 1H), 8.19 (t, J = 8.0 Hz, 2H), 8.38 (d, J = 8.0 Hz, 1H), 8.68-8.70 (m, 3H), 9.32 (d, J = 8.0 Hz, 1H), 9.46 (d, J = 8.0 Hz, 1H), 9.50 (s, 1H)

[1007] Fig.41A and Fig.41B Show 1 H NMR spectrum. Fig.41B yes Fig.41AThe enlarged view of the range from 7.4 ppm to 9.6 ppm in FIG. 2 was obtained by confirming the target compound 2mDBtQPDBq-II from the measurement results.

[1008] The obtained 3.6 g solid was purified by gradient sublimation. In the sublimation purification, the solid was heated at 395° C. for 17 hours under the conditions of a pressure of 3.6 Pa and an argon flow rate of 15 mL / min. After purification, 2.6 g of the target yellow solid was obtained with a recovery rate of 74%.

[1009] 《Physical properties of 2-[3"'-(dibenzothiophene-4-yl)-3,1':3',1":3",1"'-quaterphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBtQPDBq-II)》

[1010] Fig.42 and Fig.43 The absorption spectrum and emission spectrum of the thin film of 2mDBtQPDBq-II measured by the same measurement method as that of 2mDBtTPDBq-II are respectively shown.

[1011] Depend on Fig.42 It can be seen that the film of 2mDBtQPDBq-II shows absorption peaks near 253nm, 318nm, 337nm, 367nm and 383nm. Fig.43 It is known that the peak of the emission wavelength is around 423 nm (excitation wavelength: 383 nm). 2mDBtQPDBq-II was confirmed to emit blue-violet light. The compound of one embodiment of the present invention can be used as a host material of a light-emitting substance or a host material of a fluorescent substance in the visible region.

[1012] The phosphorescence of 2mDBtQPDBq-II was measured using the same method as that of 2mDBtTPDBq-II. Fig.44 The obtained phosphorescence spectrum is shown. From the results, it can be seen that the peak on the shortest wavelength side in the phosphorescence spectrum of 2mDBtQPDBq-II exists at 514nm, which means that 2mDBtQPDBq-II has a high T1 level. It can be seen that the thin film of 2mDBtQPDBq-II is not easy to agglomerate in the atmosphere, has little morphological change, and has good film quality.

[1013] The redox reaction characteristics were investigated by cyclic voltammetry (CV) measurement. The measurement was performed by the same measurement method as 2mDBtTPDBq-II. As a result, the oxidation potential was -6.19 eV and the reduction potential was -2.93 eV. When the oxidation potential is regarded as the HOMO energy level and the reduction potential is regarded as the LUMO energy level, the band gap between the HOMO energy level and the LUMO energy level is estimated to be 3.26 eV.

[1014] Example 7

[1015] "Synthesis Example 7"

[1016] In this synthesis example, a method for synthesizing the heterocyclic compound 2-[4″-(9-phenyl-9H-carbazole-3-yl)-1,1′:3′,1″-terphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mmpPCTPDBq) (structural formula (2007)) described in Embodiment 1 and Embodiment 2 is described. The structural formula of 2mmpPCTPDBq is shown below.

[1017] [Chemical formula 251]

[1018]

[1019] <(Step 1) Synthesis of 3-(3'-chloro-1,1'-biphenyl-4-yl)-9-phenyl-9H-carbazole>

[1020] 4.0 g (10 mmol) of 3-(4-bromophenyl)-9-phenyl-9H-carbazole, 1.6 g (10 mmol) of 3-chlorophenylboric acid, 0.61 g (2.0 mmol) of tri(o-tolyl)phosphine, 40 mL of toluene, 10 mL of ethanol and 15 mL of potassium carbonate aqueous solution (2.0 mol / L) were poured into a 200 mL three-necked flask. The mixture was degassed under reduced pressure, and then nitrogen was continuously flowed through the system. The mixture was heated to 60°C. Then, 87 mg (0.40 mmol) of palladium (II) acetate was added and the mixture was stirred at 80°C for 12 hours. After stirring, the organic layer of the obtained mixture was washed with water, and the aqueous layer was extracted with toluene. The obtained extract and the organic layer were mixed, the mixture was washed with saturated brine, and magnesium sulfate was added thereto. The obtained mixture was gravity filtered, and the obtained filtrate was concentrated to obtain 3.6 g of the target compound as a brown oil with a yield of 84%. The following (H-1) shows the synthesis scheme of this step.

[1021] [Chemical formula 252]

[1022] (H-1)

[1023]

[1024] The obtained oily substance was subjected to nuclear magnetic resonance spectroscopy ( 1 H NMR), and the analysis results are shown below.

[1025] 1H NMR (chloroform-d, 500MHz): δ = 7.30-7.34 (m, 2H), 7.39 (t, J = 8.0Hz, 1H), 7.43 (d, J = 3.5Hz, 2H), 7.47-7.50 (m, 2H), 7 .54(d,J=7.5Hz,1H), 7.58-7.70(m,8H), 7.80(d,J=8.5Hz,2H), 8.21(d,J=8.0Hz,1H), 8.40(d,J=2.0Hz,1H)

[1026] Fig.45A and Fig.45B The obtained oily substance is shown 1 H NMR spectrum. Note that Fig.45B yes Fig.45A The enlarged view of the range from 7.0 ppm to 8.5 ppm in FIG. 1. The measurement results confirmed that the target compound 3-(3'-chloro-1,1'-biphenyl-4-yl)-9-phenyl-9H-carbazole was obtained.

[1027] <(Step 2) Synthesis of 3-[3'-(4,4,5,5-tetramethyl-1,3,2-dioxaborolane-2-yl)-1,1'-biphenyl-4-yl]-9-phenyl-9H-carbazole>

[1028] 3.6 g (8.4 mmol) of 3-(3'-chloro-1,1'-biphenyl-4-yl)-9-phenyl-9H-carbazole, 2.2 g (8.4 mmol) of biboric acid pinacol ester, 2.5 g (25 mmol) of potassium acetate, and 0.28 g (0.50 mmol) of 2-di-tert-butylphosphine-2',4',6'-triisopropyl-biphenyl (tBuxphos) were poured into a 200 mL three-necked flask, and then the atmosphere in the system was replaced with nitrogen. After adding 42 mL of xylene to the mixture, the mixture was degassed under reduced pressure, and then nitrogen was continuously flowed through the system. After heating the mixture to 80°C, 0.16 g (0.2 mmol) of [1,1'-bis(diphenylphosphino)ferrocene]dichloropalladium (II) was added, and the mixture was stirred at 150°C for 27 hours. After stirring, the disappearance of 3-(3'-chloro-1,1'-biphenyl-4-yl)-9-phenyl-9H-carbazole was confirmed by thin layer chromatography, and then the obtained mixture was cooled to room temperature and then carried out to step 3. The following (H-2) shows the synthesis scheme of this step.

[1029] [Chemical formula 253]

[1030] (H-2)

[1031]

[1032] <(Step 3) Synthesis of 2-[4"-(9-phenyl-9H-carbazole-3-yl)-1,1':3',1"-terphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mmpPCTPDBq)>

[1033] To the mixture obtained in step 2, add 2.9 g (8.4 mmol) of 2-(3-chlorophenyl)dibenzo[f,h]quinoxaline, 0.55 g (1.5 mmol) of di(1-adamantane)-n-butylphosphine, 4.3 g (20 mmol) of tripotassium phosphate, and 33 mL of diethylene glycol dimethyl ether. Then, the mixture is degassed under reduced pressure, and nitrogen is continuously passed through the system. The obtained mixture is heated to 80°C, 0.12 g (0.50 mmol) of palladium (II) acetate is added, and the mixture is stirred at 150°C for 7 hours. After stirring, the precipitated solid is collected by suction filtration, and washed with toluene, water and ethanol to obtain 2.5 g of the target brown powder. The total yield of step 2 and step 3 is 42%. The following (H-3) shows the synthesis scheme of this step.

[1034] [Chemical formula 254]

[1035] (H-3)

[1036]

[1037] The obtained solid was subjected to nuclear magnetic resonance spectroscopy ( 1 H NMR), and the analysis results are shown below.

[1038] 1 H NMR (chloroform-d, 500MHz): δ = 7.31-7.34 (m, 1H), 7.44 (d, J = 4.0Hz, 1H), 7.50 (d, J = 15Hz, 2H), 7.60-7.66(m,5H), 7.72-7.87(m,14H), 8.04(s,1H), 8.22(d,J=8.0Hz,1H), 8 .36(d,J=8.0Hz,1H), 8.43(d,J=1.5Hz,1H), 8.65(s,1H), 8.67(d,J=7.5Hz,2H), 9 .26(dd, J1=8.0Hz, J2=2.0Hz, 1H), 9.46(dd, J1=8.0Hz, J2=2.0Hz, 1H), 9.48(s, 1H)

[1039] Fig.46A and Fig.46B The obtained solid 1 H NMR spectrum. Note that Fig.46B yes Fig.46AThe enlarged view of the range from 7.0 ppm to 9.6 ppm in the above figure. The measurement results confirmed that the target compound 2-[4"-(9-phenyl-9H-carbazole-3-yl)-1,1':3',1"-terphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mmpPCTPDBq) was obtained.

[1040] The obtained 2.5 g solid was purified by gradient sublimation method. In the sublimation purification, the solid was heated at 375° C. for 15 hours under the conditions of 3.6 Pa pressure and 15 mL / min argon flow rate. After sublimation purification, 2.2 g of light yellow solid was obtained with a recovery rate of 87%.

[1041] 《Physical properties of 2-[4"-(9-phenyl-9H-carbazole-3-yl)-1,1':3',1"-terphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mmpPCTPDBq)》

[1042] Fig.47 and Fig.48 The measurement results of the absorption spectrum and emission spectrum of a toluene solution of 2 mm pPCTPDBq are shown respectively. Fig.49 and Fig.50 The absorption spectrum and emission spectrum of the film of 2mmpPCTPDBq are shown respectively. A solid film is formed on a quartz substrate by vacuum evaporation. The absorption spectrum of the toluene solution is measured in the same manner as in Example 1. The absorption spectrum of the film is measured using a spectrophotometer (spectrophotometer U4100 manufactured by Hitachi High-Technologies Corporation). The emission spectrum is measured in the same manner as in Example 1.

[1043] Depend on Fig.47 It can be seen that the toluene solution of 2 mm pPCTPDBq exhibits absorption peaks near 374 nm, 354 nm and 302 nm. Fig.48 It can be seen that the peak emission wavelengths are at 385nm and 404nm (excitation wavelength: 355nm). Fig.49 It can be seen that the 2mmpPCTPDBq film shows absorption peaks near 380nm, 365nm, 330nm, 303nm, and 258nm. Fig.50 It is known that the peak of the emission wavelength is around 459 nm (excitation wavelength: 325 nm). 2 mm pPCTPDBq was confirmed to emit blue-violet light. The compound of one embodiment of the present invention can be used as a host material of a light-emitting substance or a host material of a fluorescent substance in the visible region.

[1044] The phosphorescence of 2 mmpPCTPDBq was measured in the same manner as in Example 1. Fig.51 The obtained phosphorescence spectrum is shown. From this result, it can be seen that the peak on the shortest wavelength side in the phosphorescence spectrum of 2mmpPCTPDBq exists at 514nm, which means that 2mmpPCTPDBq has a high T1 level. It can be seen that the film of 2mmpPCTPDBq is not easy to agglomerate in the atmosphere, has little morphological change, and has good film quality.

[1045] The HOMO level and LUMO level of 2 mmpPCTPDBq were measured by cyclic voltammetry (CV). The measurement method and calculation method were the same as those in Example 1.

[1046] Furthermore, CV measurement was repeated 100 times, and the oxidation-reduction wave of the 100th cycle and the oxidation-reduction wave of the 1st cycle were compared with each other to investigate the electrical stability of the compound.

[1047] The results show that in the measurement of the oxidation potential Ea [V] of 2mmpPCTPDBq, the HOMO energy level is -5.80eV. On the other hand, the LUMO energy level is -2.94eV. When the oxidation-reduction wave is repeatedly measured, in the Ea measurement, the peak intensity of the oxidation-reduction wave after the 100th cycle maintains 78% of the peak intensity of the oxidation-reduction wave in the first cycle, and in the Ec measurement, the peak intensity of the oxidation-reduction wave after the 100th cycle maintains 90% of the peak intensity of the oxidation-reduction wave in the first cycle, which shows that 2mmpPCTPDBq has a very high resistance to oxidation and reduction.

[1048] Example 8

[1049] "Synthesis Example 8"

[1050] In this synthesis example, a method for synthesizing 2-[3'-(9-phenyl-9H-carbazole-3-yl)-1,1'-biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mPCBPDBq) (structural formula (2008)) synthesized as a comparative substance of a heterocyclic compound according to one embodiment of the present invention is described. The structural formula of 2mPCBPDBq is shown below.

[1051] [Chemical formula 255]

[1052]

[1053] <Synthesis of 2-[3'-(9-phenyl-9H-carbazole-3-yl)-1,1'-biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mPCBPDBq)>

[1054] 4.2 g (5 mmol) of 2-(3'-bromo-1,1'-biphenyl-3-yl)dibenzo[f,h]quinoxaline, 1.5 g (5 mmol) of 9-phenyl-9H-carbazole-3-ylboronic acid, 0.16 mg (0.50 mmol) of tri(o-tolyl)phosphine, 25 mL of toluene, 5 mL of ethanol, and 7.5 mL of potassium carbonate aqueous solution (2.0 mol / L) were poured into a 200 mL three-necked flask. The mixture was degassed under reduced pressure, and then nitrogen was continuously flowed through the system. The mixture was heated to 60°C. Then, 52 mg (0.23 mmol) of palladium (II) acetate was added, and the mixture was stirred at 90°C for 32 hours. After stirring, the precipitated solid was collected by suction filtration and washed with water, toluene and ethanol, thereby obtaining 2.8 g of the target brown solid with a yield of 89%. The following (I-1) shows the synthesis scheme of this step.

[1055] [Chemical formula 256]

[1056] (I-1)

[1057]

[1058] The obtained solid was subjected to nuclear magnetic resonance spectroscopy ( 1 H NMR), and the analysis results are shown below.

[1059] 1 H NMR (chloroform-d, 500MHz): δ=7.29-7.33(m,1H), 7.42-7.45(m,2H), 7.50(t,J=7.5Hz ,1H), 7.52(d,J=9.0Hz,1H), 7.61-7.82(m,8H), 7.88(d,J=8.0Hz,1H), 8.08(s, 1H), 8.23(d,J=7.5Hz,1H), 8.36(d,J=7.5Hz,1H), 8.47(s,1H), 8.67(d,J=8.5 Hz,2H), 8.67(s,1H), 9.26(d,J=8.5Hz,1H), 9.46(d,J=8.0Hz,1H), 9.49(s,1H)

[1060] Fig.52A and Fig.52B The obtained solid 1 H NMR spectrum. Note that Fig.52B yes Fig.52AThe enlarged view of the range from 7.0 ppm to 9.6 ppm in FIG. 1 was obtained. The measurement results confirmed that the target compound 2-[3'-(9-phenyl-9H-carbazole-3-yl)-1,1'-biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mPCBPDBq) was obtained.

[1061] The obtained 2.1 g solid was purified by gradient sublimation. In the sublimation purification, the solid was heated at 330° C. for 15 hours under the conditions of a pressure of 3.6 Pa and an argon flow rate of 15 mL / min. After the sublimation purification, 1.9 g of the target light yellow solid was obtained with a recovery rate of 90%.

[1062] 《Physical properties of 2-[3'-(9-phenyl-9H-carbazole-3-yl)-1,1'-biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mPCBPDBq)》

[1063] The phosphorescence of 2mPCBPDBq was measured by the same method as in Example 1. Although the obtained phosphorescence spectrum is not shown, it can be seen that the peak on the shortest wavelength side in the obtained phosphorescence spectrum of 2mPCBPDBq exists at 515nm, which means that 2mPCBPDBq has a high T1 level. It can be seen that the thin film of 2mPCBPDBq is not easy to agglomerate in the atmosphere, has little morphological change, and has good film quality.

[1064] The HOMO level and LUMO level of 2mPCBPDBq were measured by cyclic voltammetry (CV). The measurement method and calculation method were the same as those in Example 1.

[1065] Furthermore, CV measurement was repeated 100 times, and the oxidation-reduction wave in the 100th cycle and the oxidation-reduction wave in the 1st cycle were compared with each other to investigate the electrical stability of the compound.

[1066] The results show that in the measurement of the oxidation potential Ea [V] of 2mPCBPDBq, the HOMO energy level is -5.84 eV. On the other hand, the LUMO energy level is -2.94 eV. When the oxidation-reduction wave is repeatedly measured, in the Ea measurement, the peak intensity of the oxidation-reduction wave after the 100th cycle maintains 78% of the peak intensity of the oxidation-reduction wave in the first cycle, and in the Ec measurement, the peak intensity of the oxidation-reduction wave after the 100th cycle maintains 80% of the peak intensity of the oxidation-reduction wave in the first cycle, which shows that 2mPCBPDBq has very high oxidation resistance and reduction resistance.

[1067] The thermal properties of 2mPCBPDBq were measured. Thermogravimetry-Differential Thermal Analysis (TG-DTA) was performed on 2mPCBPDBq. In the measurement, a high vacuum differential differential thermal balance (manufactured by Bruker AXS, TG-DTA 2410SA) was used. The measurement was performed at a heating rate of 10°C / min under a nitrogen flow (flow rate of 200mL / min) and atmospheric pressure. In addition, differential scanning calorimetry was performed using Pyris 1DSC manufactured by PerkinElmer, Inc. In the differential scanning calorimetry measurement, the temperature was increased from 300°C to 350°C (the temperature at which no decomposition of the compound occurred) at a heating rate of 40°C / min, then maintained at this temperature for 1 minute, and then cooled to -10°C at a cooling rate of 40°C / min. This operation was performed twice in succession.

[1068] In thermogravimetric-differential thermal analysis, the temperature (decomposition temperature) at which the weight obtained from thermogravimetric measurement decreases by 5% from the weight at the start of measurement is 500° C. or higher. The glass transition temperature (Tg) observed in the second temperature rise of differential scanning calorimetry is 119° C.

[1069] Example 9

[1070] In this example, thermogravimetric-differential thermal analysis and differential scanning calorimetry were performed on the heterocyclic compounds of the embodiment of the present invention obtained in Examples 1 to 5 and 7. Note that the measurement method was the same as that of Example 8.

[1071] Table 1 shows the following data of the heterocyclic compounds of the present invention obtained in Examples 1 to 5 and 7: the temperature (decomposition temperature) at which the weight obtained from thermogravimetric measurement in thermogravimetric-differential thermal analysis decreases by 5% from the weight at the start of measurement; the glass transition temperature (Tg) observed in the second temperature increase of differential scanning calorimetry; the crystallization temperature (Tc); and the melting point (Tm).

[1072] [Table 1]

[1073]

[1074] *-: Not observed

[1075] According to Table 1, the material of the present invention has a glass transition temperature higher than 100°C and good thermal properties. 2mDBtTPDBq-II has only meta-phenylene, but 2DBtTPDBq, 2DBtTPDBq-02, 2DBtTPDBq-03, 2DBtTPDBq-04, and 2mmpPCTPDBq all have both meta-phenylene and para-phenylene. It can be seen that among compounds with the same molecular weight, the compound whose skeleton includes both meta-phenylene and para-phenylene has higher heat resistance.

[1076] Example 10

[1077] In this example, the thermal properties of the heterocyclic compound according to the embodiment of the present invention and the life of a device using the heterocyclic compound were evaluated.

[1078] The thermal properties and device life of the heterocyclic compounds of the present invention synthesized in Examples 1 to 8 and comparative heterocyclic compounds were evaluated. Note that the comparative heterocyclic compounds are the following heterocyclic compounds: 2-[3'-(dibenzothiophene-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBTBPDBq-II) and 2-[3'-(9-phenyl-9H-carbazole-3-yl)-1,1'-biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mPCBPDBq), which have fewer phenylene groups between the dibenzoquinoxaline ring and the dibenzothiophenyl group or the carbazole group and smaller molecular weight than the heterocyclic compounds of the present invention. The structural formulas of 2mDBTBPDBq-II and 2mPCBPDBq are shown below.

[1079] [Chemical formula 257]

[1080]

[1081] <Manufacturing of Light-Emitting Elements 1 to 7 and Comparative Light-Emitting Element 8>

[1082] In order to evaluate the thermal properties and device life, a light-emitting device containing the heterocyclic compound in the EL layer was manufactured. The manufacturing process of the light-emitting device is described. The light-emitting device has Figure 1A The stacked structure shown.

[1083] First, as the first electrode 101, an ITSO film with a thickness of 110 nm is formed on the substrate. The electrode area of ​​the first electrode 101 is 4 mm 2 (2mm×2mm).

[1084] Next, an EL layer 103 is formed on the first electrode 101. As a hole injection layer 111, 1,3,5-tri(dibenzothiophene-4-yl)benzene (abbreviated as DBT3P-II) and molybdenum oxide are deposited by co-evaporation so that the weight ratio of DBT3P-II:molybdenum oxide in the formed layer is 2:1 and the thickness is 20 nm. Note that co-evaporation refers to an evaporation method in which a plurality of different substances are evaporated simultaneously from different evaporation sources. As a hole transport layer 112, 4-phenyl-4'-(9-phenylfluorene-9-yl)triphenylamine (abbreviated as BPAFLP) is deposited by evaporation in a thickness of 20 nm.

[1085] Next, the light emitting layer 113 is formed. First, a heterocyclic compound, N-(1,1'-biphenyl-4-yl)-9,9-dimethyl-N-[4-(9-phenyl-9H-carbazole-3-yl)phenyl]-9H-fluorene-2-amine (abbreviated as PCBBiF) and (acetylacetonato)bis(6-tert-butyl-4-phenylpyrimidinato)iridium(III) (abbreviated as [Ir(tBuppm)2(acac)]) are deposited by co-evaporation, so that the weight ratio of the heterocyclic compound:PCBBiF:[Ir(tBuppm)2(acac)] in the formed layer is 0.7:0.3:0.05 and the thickness is 20 nm. On this layer, a heterocyclic compound, PCBBiF, and [Ir(tBuppm)2(acac)] were also deposited by co-evaporation, so that the weight ratio of the heterocyclic compound:PCBBiF:[Ir(tBuppm)2(acac)] in the formed layer was 0.8:0.2:0.05 and the thickness was 20 nm. In this way, a light-emitting layer 113 with a total thickness of 40 nm was formed. Note that in the light-emitting layer 113, the above-mentioned heterocyclic compound and PCBBiF are host materials, and [Ir(tBuppm)2(acac)] is a guest material.

[1086] Next, the heterocyclic compound and BPhen were deposited in order to have a thickness of 20 nm and 10 nm respectively on the light-emitting layer 113 as the electron transport layer 114. Next, lithium fluoride (LiF) was deposited in order to have a thickness of 1 nm as the electron injection layer 115.

[1087] As the electrode 102, aluminum (Al) was deposited to a thickness of 200 nm.

[1088] Next, in a glove box with a nitrogen atmosphere, a sealing substrate was fixed to the substrate on which the EL layer 103 was formed using a sealing agent for an organic EL device, thereby sealing each light-emitting element. Specifically, the sealing agent was applied around the EL layer 103 formed on the substrate, and the substrate and the sealing substrate were bonded together, and the sealing agent was heated at 6 J / cm 2The ultraviolet light having a wavelength of 365 nm was irradiated, and a heat treatment was performed at 80° C. for 1 hour. A light-emitting element was obtained through the above steps.

[1089] <Manufacturing of Light-Emitting Element 9 and Comparative Light-Emitting Element 10>

[1090] The manufacturing methods of the light-emitting element 9 and the comparative light-emitting element 10 are the same as those of the light-emitting elements 1 to 7 and the comparative light-emitting element 8 except for the step of forming the light-emitting layer 113 .

[1091] As the light-emitting layer 113 of each of the light-emitting element 9 and the comparative light-emitting element 10, a heterocyclic compound, PCBBiF and bis[2-(6-phenyl-4-pyrimidinyl-κN3)phenyl-κC](2,4-pentanedione-κ 2 O, O') iridium (III) (abbreviated as: Ir(dppm)2(acac)), with the weight ratio of the heterocyclic compound, PCBBiF and [Ir(dppm)2(acac)] in the formed layer being 0.7:0.3:0.05 and the thickness being 20 nm. On top of it, the heterocyclic compound, PCBBiF and [Ir(dppm)2(acac)] are also deposited by co-evaporation, with the weight ratio of the heterocyclic compound:PCBBiF:[Ir(dppm)2(acac)] in the formed layer being 0.8:0.2:0.05 and the thickness being 20 nm. In this way, a light-emitting layer 113 with a total thickness of 40 nm is formed. Note that in the light-emitting layer 113, the above-mentioned heterocyclic compound and PCBBiF are the main materials, and Ir(dppm)2(acac) is the guest material.

[1092] The following shows structures of materials other than the heterocyclic compound of the embodiment of the present invention among materials contained in the EL layer of the light-emitting element.

[1093] [Chemical formula 258]

[1094]

[1095] Note that in the light-emitting element 1, the heterocyclic compound of the light-emitting layer 113 and the electron-transporting layer 114 uses 2-[3"-(dibenzothiophene-4-yl)-3,1':3',1"-terphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBtTPDBq-II) described in Example 1.

[1096] In the light-emitting element 2, the heterocyclic compound of the light-emitting layer 113 and the electron transport layer 114 used is 2-[3"-(dibenzothiophene-4-yl)-3,1':4',1"-terphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2DBtTPDBq) described in Example 2.

[1097] In the light-emitting element 3, the heterocyclic compound of the light-emitting layer 113 and the electron transport layer 114 uses 2-[4"-(dibenzothiophene-4-yl)-3,1':4',1"-terphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2DBtTPDBq-03) described in Example 3.

[1098] In the light-emitting element 4, the heterocyclic compound of the light-emitting layer 113 and the electron transport layer 114 uses 2-[4"-(dibenzothiophene-4-yl)-4,1':3',1"-terphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2DBtTPDBq-02) described in Example 4.

[1099] In the light-emitting element 5, the heterocyclic compound of the light-emitting layer 113 and the electron transport layer 114 used 2-[4"-(dibenzothiophene-4-yl)-3,1':3',1"-terphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2DBtTPDBq-04) described in Example 5.

[1100] In the light-emitting element 6, the heterocyclic compound used in the light-emitting layer 113 and the electron transport layer 114 is 2-[3"'-(dibenzothiophene-4-yl)-3,1':3',1":3",1"'-quaterphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBtQPDBq-II) described in Example 6.

[1101] In each of light-emitting elements 7 and 9, the heterocyclic compound used in the light-emitting layer 113 and the electron transport layer 114 is 2-[4"-(9-phenyl-9H-carbazole-3-yl)-1,1':3',1"-terphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mmpPCTPDBq) described in Example 7.

[1102] In the comparative light-emitting element 8, 2-[3′-(dibenzothiophene-4-yl)biphenyl-3-yl]dibenzo[f,h]quinoxaline (abbreviated as 2mDBTBPDBq-II) was used as the heterocyclic compound of the light-emitting layer 113 and the electron transport layer 114 .

[1103] In the comparative light-emitting element 10, the heterocyclic compound of the light-emitting layer 113 and the electron transport layer 114 uses 2-[3"'-(dibenzothiophene-4-yl)-3,1':3',1":3",1"'-quaterphenyl-1-yl]dibenzo[f,h]quinoxaline (abbreviation: 2mDBtQPDBq-II) described in Example 9.

[1104] Table 2 and Table 3 show the structures of the elements described in this embodiment.

[1105] [Table 2]

[1106]

[1107] *2mDBtTPDBq-II:PCBBiF:[Ir(tBuppm)2(acac)](0.7:0.3:0.05 20nm\0.8:0.2:0.05 20nm)

[1108] **2DBtTPDBq:PCBBiF:[Ir(tBuppm)2(acac)](0.7:0.3:0.05 20nm\0.8:0.2:0.0520nm)

[1109] ***2DBtTPDBq-03:PCBBiF:[Ir(tBuppm)2(acac)](0.7:0.3:0.05 20nm\0.8:0.2:0.05 20nm)

[1110] ****2DBtTPDBq-02:PCBBiF:[Ir(tBuppm)2(acac)](0.7:0.3:0.05 20nm\0.8:0.2:0.05 20nm)

[1111] *****2DBtTPDBq-04:PCBBiF:[Ir(tBuppm)2(acac)](0.7:0.3:0.05 20nm\0.8:0.2:0.05 20nm)

[1112] ******2mDBtQPDBq-II:PCBBiF:[Ir(tBuppm)2(acac)](0.7:0.3:0.05 20nm\0.8:0.2:0.05 20nm)

[1113] *******2mmpPCTPDBq:PCBBiF:[Ir(tBuppm)2(acac)](0.7:0.3:0.05 20nm\0.8:0.2:0.05 20nm)

[1114] ********2mDBTBPDBq-II:PCBBiF:[Ir(tBuppm)2(acac)](0.7:0.3:0.05 20nm\0.8:0.2:0.05 20nm)

[1115] [Table 3]

[1116]

[1117] *****

[1118] 2mmpPCTPDBq:PCBBiF:Ir(dppm)2(acac)(0.7:0.3:0.05 20nm\0.8:0.2:0.0520nm)

[1119] ****

[1120] *****

[1121] 2mPCBPDBq:PCBBiF:Ir(dppm)2(acac)(0.7:0.3:0.05 20nm\0.8:0.2:0.05 20nm)

[1122] *****

[1123] <Characteristics of Light-Emitting Elements 1 to 7 and Comparative Light-Emitting Element 8>

[1124] Table 4 shows the characteristics of Light-Emitting Elements 1 to 7 and Comparative Light-Emitting Element 8. As can be seen from Table 4, Light-Emitting Elements 1 to 7 and Comparative Light-Emitting Element 8 have good characteristics.

[1125] [Table 4]

[1126]

[1127] Fig.53 The initial brightness of light emitting elements 1 to 6 and comparative light emitting element 8 is 5000 cd / m 2 The results of the constant current drive test are as follows. Fig.53As shown, light-emitting elements 1 to 6 and comparative light-emitting element 8 have high reliability. However, the slopes of the degradation curves of light-emitting elements 3 and 4 are slightly high. Each of 2DBtTPDBq-03 used as the main material of light-emitting element 3 and 2DBtTPDBq-02 used as the main material of light-emitting element 4 has a molecular structure having one meta-phenylene group and two para-phenylene groups as arylene groups. On the other hand, in light-emitting element 1, light-emitting element 2, and light-emitting element 5 having very high reliability, 2mDBtTPDBq-II, 2DBtTPDBq, and 2DBtTPDBq-04 are used for the light-emitting layer, respectively. These three materials all have a molecular structure including one para-phenylene group or no para-arylene group. Therefore, in order to achieve both high reliability and high heat resistance, it is preferred to have one para-phenylene group and two meta-phenylene groups in the molecular structure. Furthermore, it is preferred that the meta-biphenyl-diyl group is formed in such a manner that two meta-phenylene groups are continuously bonded from one side of the dibenzo[f,h]quinoxaline skeleton, because higher reliability can be obtained, and an element having higher reliability than the comparative light-emitting element 8 can be provided. When the meta-biphenyl-diyl group is formed in such a manner that two meta-phenylene groups are continuously bonded from one side of the dibenzo[f,h]quinoxaline skeleton, the third phenylene group from the dibenzo[f,h]quinoxaline skeleton is more preferably bonded at the para position, because high heat resistance can be achieved.

[1128] <Characteristics of Light-Emitting Element 9 and Comparative Light-Emitting Element 10>

[1129] Table 5 shows the characteristics of the light emitting element 9 and the comparative light emitting element 10. As can be seen from Table 5, the light emitting element 9 and the comparative light emitting element 10 have good characteristics.

[1130] [Table 5]

[1131]

[1132] Fig.54 The results of driving tests of the light emitting element 9 and the comparative light emitting element 10 at a constant current of 2 mA are shown. Fig.54 It can be seen that the LT of each of the light emitting element 9 and the comparative light emitting element 10 is 50 More than 1000 hours, which means high reliability. Here, the slope of the degradation curve of light-emitting element 9 is smaller than that of comparative light-emitting element 10, and as a result, light-emitting element 9 has higher reliability than comparative light-emitting element 10. Therefore, as described above, in order to obtain high reliability, as a divalent group connecting the dibenzo[f,h]quinoxaline skeleton and the carbazole group in the molecular structure, a terphenyl-diyl group in which three arylene groups are continuously bonded is preferred to a biphenyl-diyl group in which two phenylene groups are continuously bonded.

[1133] <Heat resistance evaluation>

[1134] The manufactured light-emitting elements were subjected to a test for evaluating thermal properties. First, the light-emitting elements were placed in a 100°C environment for a specified time. Then, the light-emitting elements were taken out of the environment to cool to room temperature, and the external quantum efficiency of the light-emitting elements was measured. After the measurement, the following cycle was repeated: the light-emitting elements were placed in a 100°C environment again, placed for a specified time, taken out of the environment, and the external quantum efficiency was measured.

[1135] Fig.55 The measurement results are shown. Note that the horizontal axis in the graph represents the cumulative storage time (h) of the light-emitting element placed in an environment of 100°C. The vertical axis in the graph represents the retention rate (%) of the external quantum efficiency when the maximum external quantum efficiency at the beginning of the thermal property evaluation is estimated to be 100%. Note that the initial external quantum efficiency of the element is almost the same, that is, about 28%.

[1136] like Fig.55 As shown, the comparative light-emitting element 8 maintains the initial external quantum efficiency for 5 hours from the beginning of storage, and then the external quantum efficiency deteriorates sharply, and after 25 hours, it drops to 0%. On the other hand, the light-emitting element 1 maintains the initial external quantum efficiency for 25 hours from the beginning of storage, showing higher thermal properties than the comparative light-emitting element 8. In addition, the light-emitting element 2 and the light-emitting element 5 almost maintain the initial external quantum efficiency after 50 hours, so they have good thermal properties. Moreover, the light-emitting elements 3 and 4 have a retention rate of more than 85% after 1000 hours, which means very good thermal properties. 2DBtTPDBq-03 used as the main material of the light-emitting element 3 and 2DBtTPDBq-02 used as the main material of the light-emitting element 4 have two meta-phenylene groups and one para-phenylene group as arylene groups in their molecular structures. When having such a structure, there is a tendency for high heat resistance. When the molecular structure has a terphenylene structure (a structure in which three phenylene groups are continuously bonded), specifically a structure having two m-phenylene groups and one p-phenylene group as an arylene group, the entire molecule may have high planarity and Tg may also be high. In other words, a molecular structure with higher planarity is preferred for heat resistance.

[1137] In the heterocyclic compound of one embodiment of the present invention, the number of central phenylene groups is three or more, and the molecular weight is larger than that of the heterocyclic compound used for comparative light-emitting element 8. Therefore, the light-emitting element using the heterocyclic compound of one embodiment of the present invention can have good thermal properties.

[1138] In addition, in general, when a compound with a large molecular weight is used in the light-emitting layer, the external quantum efficiency tends to decrease due to the increase in the refractive index. However, the initial external quantum efficiencies of light-emitting elements 1 to 5 and the comparative light-emitting element 8 are almost the same. Therefore, it can be confirmed that when the heterocyclic compound of one embodiment of the present invention is used in the light-emitting layer, a light-emitting element with good thermophysical properties can be realized without reducing the external quantum efficiency of the light-emitting element.

[1139] Description of Reference Numerals

[1140] 101: first electrode; 102: second electrode; 103: EL layer; 111: hole injection layer; 112: hole transport layer; 113: light emitting layer; 114: electron transport layer; 115: electron injection layer; 501: first electrode; 502: second electrode; 511: first light emitting unit; 512: second light emitting unit; 513: charge generation layer; 601: drive circuit portion (source side drive circuit); 602: pixel portion; 603: drive circuit portion (gate side drive circuit); 604: sealing substrate; 605: sealant; 607: space; 608: guide wiring; 609: FPC (flexible printed circuit); 610: element substrate; 611: switch TFT; 612: second light emitting unit; 613: charge generation layer; 614: first electrode; 615: second electrode; 616: first light emitting unit; 617: second light emitting unit; 618: second light emitting unit; 619: second light emitting unit; 620: second light emitting unit; 621: second light emitting unit; 622: second light emitting unit; 623: second light emitting unit; 624: second light emitting unit; 625: second light emitting unit; 626: second light emitting unit; 627: second light emitting unit; 628: second light emitting unit; 629: first electrode; 630: first electrode; 631: second electrode; 632: second electrode; 633: first electrode; 634: second electrode; 635: first electrode; 636: second electrode; 637: first electrode; 638: first electrode; 639: second electrode; 640: first electrode; 641: first electrode; 642: second electrode; 643: 12: TFT for current control; 613: first electrode; 614: insulator; 616: EL layer; 617: second electrode; 618: light emitting element; 623: n-channel TFT; 624: p-channel TFT; 901: frame; 902: liquid crystal layer; 903: backlight; 904: frame; 905: driver IC; 906: terminal; 951: substrate; 952: electrode; 953: insulating layer; 954: partition wall layer; 955: EL layer; 956: electrode; 1001: substrate; 1002: base insulating film; 1003: gate insulating film; 1006: gate electrode; 1007: gate electrode; 1008: gate electrode; 1020: interlayer insulating film; 10 21: interlayer insulating film; 1022: electrode; 1024: electrode; 1025: partition wall; 1028: EL layer; 1029: electrode; 1030: black layer; 1031: sealing substrate; 1032: sealant; 1037: interlayer insulating film; 1040: pixel portion; 1041: drive circuit portion; 1042: peripheral portion; 2001: frame; 2002: light source; 3001: lighting device; 3002: display device; 5000: display area; 5001: display area; 5002: display area; 5003: display area; 5004: display area; 5005: display area; 7101: frame; 7103: display portion; 7105: bracket; 71 07: Display unit; 7109: Operation key; 7110: Remote control unit; 7201: Main body; 7202: Frame; 7203: Display unit; 7204: Keyboard; 7205: External connection port; 7206: Pointing device; 7301: Frame; 7302: Frame; 7303: Connection unit; 7304: Display unit; 7305: Display unit; 7306: Speaker unit; 7307: Recording medium insertion unit; 7308: LED light; 7309: Operation key; 7310: Connection terminal; 7311: Sensor; 7401: Frame; 7402: Display unit; 7403: Operation button; 7404: External connection port; 7405: Speaker; 7406: Microphone

[1141] This application is based on Japanese Patent Application No. 2015-209351 filed with Japan Patent Office on October 23, 2015, the entire contents of which are incorporated herein by reference.

Claims

1. A compound represented by the following formula:

2. A synthesis method represented by formula (H-1): (H-1) 3. A synthesis method represented by formula (H-2): (H-2) 4. The synthesis method according to claim 2 or 3, wherein The reaction is carried out in a solution to which a palladium catalyst is added.

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