ELECTRONIC BARRIER MATERIAL AND ORGANIC SEMICONDUCTOR ELEMENT

Abstract

A compound represented by the following general formula is useful as an electron barrier material. R.sup.1 to R.sup.21 each are H, a deuterium atom, or a substituent except a cyano group; X represents O or S.

##STR00001##

Claims

1. An electron barrier material containing a compound represented by the following general formula (1): ##STR00350## wherein R.sup.1 to R.sup.21 each independently represent a hydrogen atom, a deuterium atom, or a substituent not including a cyano group; one combination of R.sup.2 and R.sup.13, R.sup.13 and R.sup.14, and R.sup.14 and R.sup.15 can bond to each other to form a benzofuro skeleton or a benzothieno skeleton; R.sup.1 to R.sup.11, and R.sup.16 to R.sup.21 do not bond to the other R.sup.1 to R.sup.11, R.sup.16 to R.sup.21 or R.sup.12 to R.sup.15 to form a cyclic structure; and X represents an oxygen atom or a sulfur atom.

2. The electron barrier material according to claim 1, wherein R.sup.1 to R.sup.21 do not bond to the other R.sup.1 to R.sup.21 to form a cyclic structure.

3. The electron barrier material according to claim 1, wherein R.sup.1 to R.sup.21 each independently represent a hydrogen atom, a deuterium atom, an optionally-deuterated alkyl group, or an optionally-deuterated phenyl group.

4. The electron barrier material according to claim 1, wherein R.sup.1 to R.sup.11, R.sup.20 and R.sup.21 each independently represent a hydrogen atom or a deuterium atom.

5. The electron barrier material according to claim 1, wherein R.sup.12 to R.sup.15 each independently represent a hydrogen atom or a deuterium atom.

6. The electron barrier material according to claim 1, wherein R.sup.16 to R.sup.19 each independently represent a hydrogen atom or a deuterium atom.

7. The electron barrier material according to claim 1, wherein X is an oxygen atom.

8. The electron barrier material according to claim 1, which is used in combination with a compound represented by the following general formula (G): ##STR00351## wherein one of X.sup.1 and X.sup.2 is a nitrogen atom, and the other is a boron atom; R.sup.1 to R.sup.26, A.sup.1 and A.sup.2 each independently represent a hydrogen atom, a deuterium atom, or a substituent; R.sup.1 and R.sup.2, R.sup.2 and R.sup.3, R.sup.3 and R.sup.4, R.sup.4 and R.sup.5, R.sup.5 and R.sup.6, R.sup.6 and R.sup.7, R.sup.7 and R.sup.8, R.sup.8 and R.sup.9, R.sup.9 and R.sup.10, R.sup.10 and R.sup.11, R.sup.11 and R.sup.12, R.sup.13 and R.sup.14, R.sup.14 and R.sup.15, R.sup.15 and R.sup.16, R.sup.16 and R.sup.17, R.sup.17 and R.sup.18, R.sup.18 and R.sup.19, R.sup.19 and R.sup.20, R.sup.20 and R.sup.21, R.sup.21 and R.sup.22, R.sup.22 and R.sup.23, R.sup.23 and R.sup.24, R.sup.24 and R.sup.25, and R.sup.25 and R.sup.26 can bond to each other to form a cyclic structure; and provided that when X.sup.1 is a nitrogen atom, R.sup.17 and R.sup.18 bond to each other to be a single bond to form a pyrrole ring, and when X.sup.2 is a nitrogen atom, R.sup.21 and R.sup.22 bond to each other to be a single bond to form a pyrrole ring.

9. An organic semiconductor device containing the electron barrier material according to claim 1.

10. The organic semiconductor device according to claim 9, wherein the organic semiconductor device is an organic electroluminescent device having an anode, a cathode, and at least two organic layers containing an electron barrier layer that contains the above electron barrier material and a light emitting layer, between the anode and the cathode.

11. The organic semiconductor device according to claim 10, wherein the light emitting layer contains a host material and a delayed fluorescent material.

12. The organic semiconductor device according to claim 10, wherein the light emitting layer contains a host material, a delayed florescent material and a fluorescence emitting material, and the amount of light emitted from the fluorescence emitting material is the largest among the light from the device.

13. The organic semiconductor device according to claim 10, wherein the light emitting layer is adjacent to the electron barrier layer.

14. The organic semiconductor device according to claim 10, wherein the light emitting layer contains the compound represented by the following general formula (G): ##STR00352## wherein one of X.sup.1 and X.sup.2 is a nitrogen atom, and the other is a boron atom; R.sup.1 to R.sup.26, A.sup.1 and A.sup.2 each independently represent a hydrogen atom, a deuterium atom, or a substituent; R.sup.1 and R.sup.2, R.sup.2 and R.sup.3, R.sup.3 and R.sup.4, R.sup.4 and R.sup.5, R.sup.5 and R.sup.6, R.sup.6 and R.sup.7, R.sup.7 and R.sup.8, R.sup.8 and R.sup.9, R.sup.9 and R.sup.10, R.sup.10 and R.sup.11, R.sup.11 and R.sup.12, R.sup.13 and R.sup.14, R.sup.14 and R.sup.15, R.sup.15 and R.sup.16, R.sup.16 and R.sup.17, R.sup.17 and R.sup.18, R.sup.18 and R.sup.19, R.sup.19 and R.sup.20, R.sup.20 and R.sup.21, R.sup.21 and R.sup.22, R.sup.22 and R.sup.23, R.sup.23 and R.sup.24, R.sup.24 and R.sup.25, and R.sup.25 and R.sup.26 can bond to each other to form a cyclic structure; provided that when X.sup.1 is a nitrogen atom, R.sup.17 and R.sup.18 bond to each other to be a single bond to form a pyrrole ring, and when X.sup.2 is a nitrogen atom, R.sup.21 and R.sup.22 bond to each other to be a single bond to form a pyrrole ring.

Description

DESCRIPTION OF EMBODIMENTS

[0023] Hereinafter, the contents of the present invention will be described in detail. The constituent elements can be described below with reference to representative embodiments and specific examples of the present invention, but the present invention is not limited to the embodiments and the examples. In this application, a numerical range expressed as to means a range which includes the numerical values described before and after to as the lower limit value and the upper limit value. Further, in this application, consisting of means that it contains only what is described before consisting of and does not contain anything else. Furthermore, some or all of the hydrogen atoms that are present in the compounds used in the present invention can be substituted with deuterium atoms (.sup.2H, deuterium D). In the chemical structural formula of the present description, the hydrogen atom is indicated by H, or the indication thereof is omitted. For example, when the indication of an atom bonding to a ring skeleton forming carbon atom of a benzene ring is omitted, it is assumed that, at a location where the indication is omitted, H bonds to the ring skeleton forming carbon atom. In the present description, the term of substituent means an atom or a group of atoms other than a hydrogen atom and a deuterium atom. Meanwhile, the expression of substituted or unsubstituted or optionally substituted means that a hydrogen atom can be substituted with a deuterium atom or a substituent. Transparent in the present invention means that the visible light transmittance is 50% or more, preferably 80% or more, more preferably 90% or more, further preferably 99% or more. The visible light transmittance can be measured with a UV/visible light spectrophotometer.

[Compound Represented by General Formula (1)]

[0024] In the present invention, a compound represented by the following general formula (1) is used.

##STR00005##

[0025] In the general formula (1), R.sup.1 to R.sup.21 each independently represent a hydrogen atom, a deuterium atom, or a substituent not including a cyano group.

[0026] In one aspect of the present invention, the substituent of R.sup.1 to R.sup.21 are each independently a substituent having a Hammett's p value falling within a range of 0.3 to 0.3. In one preferred aspect of the present invention, the substituent of R.sup.1 to R.sup.21 are each independently a substituent having a Hammett's p value falling within a range of 0.2 to 0.2. In one preferred aspect of the present invention, the substituent of R.sup.1 to R.sup.21 are each independently a substituent having a Hammett's p value falling within a range of 0.1 to 0.1. In one aspect of the present invention, the substituent of R.sup.1 to R.sup.21 are each independently a substituent having a Hammett's p value falling within a range of larger than 0 and 0.3 or less. In one aspect of the present invention, the substituent of R.sup.1 to R.sup.21 are each independently a substituent having a Hammett's p value falling within a range of 0.3 or more and less than 0.

[0027] Here, the Hammett's p value, which is proposed by L. P. Hammett, indicates the quantified effect of a substituent on the reaction rate or equilibrium of a para-substituted benzene derivative. Specifically, the value is a constant (p) peculiar to the substituent in the following equation that is established between a substituent and a reaction rate constant or an equilibrium constant in a para-substituted benzene derivative.

[00001]$\log \left(k/k_0\right)=p$$\mathrm{or}$$\log \left(K/K_0\right)=p$

In the equation, k.sub.0 represents a rate constant of a benzene derivative having no substituent, k represents a rate constant of a benzene derivative substituted with a substituent, K.sub.0 represents an equilibrium constant of a benzene derivative having no substituent, K represents an equilibrium constant of a benzene derivative substituted with a substituent, and p represents a reaction constant determined by the type and condition of the reaction. In relation to descriptions on the Hammett's p value and the numerical value of each substituent in the present invention, the description on the p value can be referred to in Hansch, C., et. al., Chem. Rev., 91, 165-195(1991). A group having a negative Hammett's p value tends to exhibit electron-donating performance (donor-like performance) and a group having a positive Hammett's p value tends to exhibit electron-accepting performance (acceptor-like performance).

[0028] In one aspect of the present invention, R.sup.1 to R.sup.21 are each independently a substituent not having an unshared electron pair. In one aspect of the present invention, R.sup.1 to R.sup.21 are each independently a substituent not having a electron.

[0029] In one aspect of the present invention, R.sup.1 to R.sup.21 are each independently a hydrogen atom, or selected from the group consisting of a deuterium atom, an alkyl group, an aryl group, and a group of a combination of these. In one preferred aspect of the present invention, R.sup.1 to R.sup.21 are each independently a hydrogen atom, a deuterium atom, an optionally-deuterated alkyl group, or a phenyl group optionally substituted with a deuterium atom. In one aspect of the present invention, R.sup.1 to R.sup.21 are each independently a hydrogen atom, a deuterium atom, or a phenyl group optionally substituted with a deuterium atom. In one aspect of the present invention, R.sup.1 to R.sup.21 are each independently a hydrogen atom, a deuterium atom, or an optionally-deuterated alkyl group. In one aspect of the present invention, R.sup.1 to R.sup.11, R.sup.20 and R.sup.21 are each independently a hydrogen atom or a deuterium atom. In one aspect of the present invention, R.sup.12 to R.sup.15 are each independently a hydrogen atom or a deuterium atom. In one aspect of the present invention, R.sup.16 to R.sup.19 are each independently a hydrogen atom or a deuterium atom. In one aspect of the present invention, R.sup.1 to R.sup.21 are each independently a hydrogen atom or a deuterium atom.

[0030] In this application, alkyl group can be linear, branched or cyclic. Further, two or more types of the linear portion, the cyclic portion, and the branched portion can be mixed. The number of carbon atoms of the alkyl group can be, for example, one or more, two or more, or four or more. Further, the number of carbon atoms can be 30 or less, 20 or less, 10 or less, 6 or less, or 4 or less. Specific examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, an n-pentyl group, an isopentyl group, an n-hexyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. In one aspect of the present invention, the carbon number of the alkyl group is 1 to 4. In one aspect of the present invention, the alkyl group is a methyl group. In one aspect of the present invention, the alkyl group is an isopropyl group. In one aspect of the present invention, the alkyl group is a tert-butyl group. In the case where plural alkyl groups exist in the molecule represented by the general formula (1), these alkyl groups can be the same as or different from each other. In one aspect of the present invention, the alkyl groups in the molecule represented by the general formula (1) are all the same. The number of the alkyl groups in the molecule represented by the general formula (1) can be 0 or more, 1 or more, 2 or more, 4 or more, or 8 or more. The number of the alkyl groups in the molecule represented by the general formula (1) can be 20 or less, 10 or less, 5 or less, or 3 or less. The number of the alkyl groups in the molecule represented by the general formula (1) can be 0.

[0031] In this application, aryl group can be a monocycle, or can be a fused ring in which two or more rings are fused. In the case of the fused ring, the number of rings to be fused is preferably 2 to 6, and, for example, can be selected from 2 to 4. Specific examples of the ring include a benzene ring, a naphthalene ring, and an anthracene ring. Preferred are a benzene ring and a naphthalene ring, and especially preferred is a benzene ring. Specific examples of the aryl group include a phenyl group, a 1-naphthyl group, and a 2-naphthyl group, and preferred is a phenyl group. A preferred aryl group can be substituted with a substituent selected from the group consisting of a deuterium atom, an alkyl group, an aryl group, and a group of a combination of these. An unsubstituted aryl group, especially an unsubstituted phenyl group is also preferred. In one aspect of the present invention, the aryl groups in the molecule represented by the general formula (1) are all the same. The number of the aryl groups in the molecule represented by the general formula (1) can be 0 or more, 1 or more, 2 or more, or 4 or more. The number of the aryl groups in the molecule represented by the general formula (1) can be 10 or less, 5 or less, 3 or less, 2 or less, or 1 or less. The number of the aryl groups in the molecule represented by the general formula (1) can be 0.

[0032] One combination of R.sup.12 and R.sup.13, R.sup.13 and R.sup.14, and R.sup.14 and R.sup.15 can bond to each other to form a benzofuro skeleton or a benzothieno skeleton. Any further ring is not fused with the benzofuro skeleton and the benzothieno skeleton referred to herein. In one aspect of the present invention, R.sup.12 and R.sup.13 bond to each other to form a benzofuro skeleton or a benzothieno skeleton. In one aspect of the present invention, R.sup.13 and R.sup.14 bond to each other to form a benzofuro skeleton or a benzothieno skeleton. In one aspect of the present invention, R.sup.14 and R.sup.15 bond to each other to form a benzofuro skeleton or a benzothieno skeleton. In one aspect of the present invention, R.sup.12 and R.sup.13, R.sup.13 and R.sup.14, and R.sup.14 and R.sup.15 all do not bond to each other to form a cyclic structure.

[0033] R.sup.1 to R.sup.11, and R.sup.16 to R.sup.21 do not bond to any of the other R.sup.1 to R.sup.21 to form a cyclic structure. For example, R.sup.1 does not bond to any of R.sup.2 to R.sup.21 to form a cyclic structure. The compound represented by the general formula (1) tends to be superior to compounds in which at least one of R.sup.1 to R.sup.11 and R.sup.16 to R.sup.21 bonds to any of the other R.sup.1 to R.sup.21 to form a cyclic structure.

[0034] In the general formula (1), X represents an oxygen atom or a sulfur atom. In one aspect of the present invention, X is a sulfur atom. In one preferred aspect of the present invention, X is an oxygen atom.

[0035] Specific examples of the group bonding to the phenylene group substituted with R.sup.8 to R.sup.11 from the right side thereof (5-membered structure substituted with R.sup.12 to R.sup.21) in the general formula (1) are shown below. However, the structures which can be adopted in this invention are not construed as limiting to these specific examples. In this application, * indicates a bonding site.

##STR00006## ##STR00007## ##STR00008## ##STR00009##

[0036] Those produced by substituting all hydrogen atoms in the above Y1 to Y18 with deuterium atoms are exemplified here as Y19 to Y36. Those produced by deuterating all hydrogen atoms of the methyl group (CH.sub.3) existing in the above Y2 to Y8, and Y11 to Y17, or all hydrogen atoms of the phenyl group (C.sub.6H.sub.5) therein are exemplified here as Y37 to Y50. In one aspect of the present invention, the group is selected from Y1 to Y50. In one aspect of the present invention, the group is selected from Y1 to Y9, Y19 to Y27, and Y37 to Y43. In one aspect of the present invention, the group is selected from Y10 to Y18, Y28 to Y36, and Y44 to Y50. In one aspect of the present invention, the group is selected from Y1, Y9, Y10, Y18, Y19, Y27, Y28, and Y36. In one aspect of the present invention, the group is selected from Y2 to Y4, Y11 to Y13, Y20 to Y22, Y29 to Y31, Y37 to Y39, and Y44 to Y46. In one aspect of the present invention, the group is selected from Y5 to Y8, Y14 to Y17, Y23 to Y26, Y32 to Y35, Y40 to Y43, and Y47 to Y50. In one aspect of the present invention, the group is selected from Y9, Y18, Y27, and Y36.

[0037] The phenylene group substituted with R.sup.8 to R.sup.11 in the general formula (1) is preferably a phenylene group optionally substituted with a deuterium atom. Examples thereof include an unsubstituted phenylene group, and a phenylene group with R.sup.8 to R.sup.11 of deuterium atoms.

[0038] Specific examples of the group bonding to the phenylene group substituted with R.sup.8 to R.sup.11 from the right side thereof (the dibenzofuryl group substituted with R.sup.1 to R.sup.7) in the general formula (1) are shown below. However, the structures which can be adopted in this invention are not construed as limiting to these specific examples. In this application, * indicates a bonding site, and D represents a deuterium atom.

##STR00010## ##STR00011##

[0039] In one aspect of the present invention, the group is selected from Z1 to Z11. In one aspect of the present invention, the group is Z1 or Z8. In one aspect of the present invention, the group is selected from Z2, Z5, and Z9. In one aspect of the present invention, the group is selected from Z4, Z7, and Z11. In one aspect of the present invention, the group is selected from Z3, Z4, Z6, Z7, Z10, and Z11.

[0040] The molecular weight of the compound represented by the general formula (1) is preferably 1500 or less, more preferably 1200 or less, further preferably 1000 or less, still further preferably 900 or less, for example, when there is an intention to form and use a film of an organic layer containing the compound represented by the general formula (1) through a vapor deposition method. The lower limit value of the molecular weight is the molecular weight of the smallest compound in the compound group represented by the general formula (1).

[0041] The compound represented by the general formula (1) can be formed into a film by a coating method regardless of the molecular weight. When the coating method is used, even a compound having a relatively large molecular weight can be formed into a film. The compound represented by the general formula (1) has an advantage of being easily dissolved in an organic solvent. For this reason, the compound represented by the general formula (1) is easily applicable to a coating method and is easily purified to increase its purity.

[0042] It is preferable that the compound represented by the general formula (1) does not include a metal atom and a boron atom. For example, as the compound represented by the general formula (1), a compound including an atom selected from the group consisting of a carbon atom, a hydrogen atom, a deuterium atom, a nitrogen atom, an oxygen atom, and a sulfur atom can be selected. For example, as the compound represented by the general formula (1), a compound including an atom selected from the group consisting of a carbon atom, a hydrogen atom, a deuterium atom, a nitrogen atom, and an oxygen atom can be selected. For example, as the compound represented by the general formula (1), a compound including an atom selected from the group consisting of a carbon atom, a hydrogen atom, a nitrogen atom, and an oxygen atom can be selected.

[0043] Hereinafter, specific examples of the compound represented by the general formula (1) will be given. However, the group represented by the general formula (1) that can be adopted in the present invention is not construed as limiting to these specific examples.

[0044] First, specific examples of the compound having a structure represented by the following general formula (1a) are shown below. In Table 1, the structures of Compounds 1 to 352 are specified by specifying the groups of Z and Y of the compounds.

##STR00012##

TABLE-US-00001 TABLE 1 No. Z Y 1 Z1 Y1 2 Z1 Y2 3 Z1 Y3 4 Z1 Y4 5 Z1 Y5 6 Z1 Y6 7 Z1 Y7 8 Z1 Y8 9 Z1 Y9 10 Z1 Y10 11 Z1 Y11 12 Z1 Y12 13 Z1 Y13 14 Z1 Y14 15 Z1 Y15 16 Z1 Y16 17 Z1 Y17 18 Z1 Y18 19 Z1 Y19 20 Z1 Y20 21 Z1 Y21 22 Z1 Y22 23 Z1 Y23 24 Z1 Y24 25 Z1 Y25 26 Z1 Y26 27 Z1 Y27 28 Z1 Y28 29 Z1 Y29 30 Z1 Y30 31 Z1 Y31 32 Z1 Y32 33 Z1 Y33 34 Z1 Y34 35 Z1 Y35 36 Z1 Y36 37 Z1 Y37 38 Z1 Y38 39 Z1 Y39 40 Z1 Y40 41 Z1 Y41 42 Z1 Y42 43 Z1 Y43 44 Z1 Y44 45 Z1 Y45 46 Z1 Y46 47 Z1 Y47 48 Z1 Y48 49 Z1 Y49 50 Z1 Y50 51 Z2 Y1 52 Z2 Y2 53 Z2 Y3 54 Z2 Y4 55 Z2 Y5 56 Z2 Y6 57 Z2 Y7 58 Z2 Y8 59 Z2 Y9 60 Z2 Y10 61 Z2 Y11 62 Z2 Y12 63 Z2 Y13 64 Z2 Y14 65 Z2 Y15 66 Z2 Y16 67 Z2 Y17 68 Z2 Y18 69 Z2 Y19 70 Z2 Y20 71 Z2 Y21 72 Z2 Y22 73 Z2 Y23 74 Z2 Y24 75 Z2 Y25 76 Z2 Y26 77 Z2 Y27 78 Z2 Y28 79 Z2 Y29 80 Z2 Y30 81 Z2 Y31 82 Z2 Y32 83 Z2 Y33 84 Z2 Y34 85 Z2 Y35 86 Z2 Y36 87 Z2 Y37 88 Z2 Y38 89 Z2 Y39 90 Z2 Y40 91 Z2 Y41 92 Z2 Y42 93 Z2 Y43 94 Z2 Y44 95 Z2 Y45 96 Z2 Y46 97 Z2 Y47 98 Z2 Y48 99 Z2 Y49 100 Z2 Y50 101 Z3 Y1 102 Z3 Y2 103 Z3 Y3 104 Z3 Y4 105 Z3 Y5 106 Z3 Y6 107 Z3 Y7 108 Z3 Y8 109 Z3 Y9 110 Z3 Y10 111 Z3 Y11 112 Z3 Y12 113 Z3 Y13 114 Z3 Y14 115 Z3 Y15 116 Z3 Y16 117 Z3 Y17 118 Z3 Y18 119 Z3 Y19 120 Z3 Y20 121 Z3 Y21 122 Z3 Y22 123 Z3 Y23 124 Z3 Y24 125 Z3 Y25 126 Z3 Y26 127 Z3 Y27 128 Z3 Y28 129 Z3 Y29 130 Z3 Y30 131 Z3 Y31 132 Z3 Y32 133 Z3 Y33 134 Z3 Y34 135 Z3 Y35 136 Z3 Y36 137 Z3 Y37 138 Z3 Y38 139 Z3 Y39 140 Z3 Y40 141 Z3 Y41 142 Z3 Y42 143 Z3 Y43 144 Z3 Y44 145 Z3 Y45 146 Z3 Y46 147 Z3 Y47 148 Z3 Y48 149 Z3 Y49 150 Z3 Y50 151 Z4 Y1 152 Z4 Y2 153 Z4 Y3 154 Z4 Y4 155 Z4 Y5 156 Z4 Y6 157 Z4 Y7 158 Z4 Y8 159 Z4 Y9 160 Z4 Y10 161 Z4 Y11 162 Z4 Y12 163 Z4 Y13 164 Z4 Y14 165 Z4 Y15 166 Z4 Y16 167 Z4 Y17 168 Z4 Y18 169 Z4 Y19 170 Z4 Y20 171 Z4 Y21 172 Z4 Y22 173 Z4 Y23 174 Z4 Y24 175 Z4 Y25 176 Z4 Y26 177 Z4 Y27 178 Z4 Y28 179 Z4 Y29 180 Z4 Y30 181 Z4 Y31 182 Z4 Y32 183 Z4 Y33 184 Z4 Y34 185 Z4 Y35 186 Z4 Y36 187 Z4 Y37 188 Z4 Y38 189 Z4 Y39 190 Z4 Y40 191 Z4 Y41 192 Z4 Y42 193 Z4 Y43 194 Z4 Y44 195 Z4 Y45 196 Z4 Y46 197 Z4 Y47 198 Z4 Y48 199 Z4 Y49 200 Z4 Y50 201 Z5 Y1 202 Z5 Y2 203 Z5 Y3 204 Z5 Y4 205 Z5 Y5 206 Z5 Y6 207 Z5 Y7 208 Z5 Y8 209 Z5 Y9 210 Z5 Y10 211 Z5 Y11 212 Z5 Y12 213 Z5 Y13 214 Z5 Y14 215 Z5 Y15 216 Z5 Y16 217 Z5 Y17 218 Z5 Y18 219 Z5 Y19 220 Z5 Y20 221 Z5 Y21 222 Z5 Y22 223 Z5 Y23 224 Z5 Y24 225 Z5 Y25 226 Z5 Y26 227 Z5 Y27 228 Z5 Y28 229 Z5 Y29 230 Z5 Y30 231 Z5 Y31 232 Z5 Y32 233 Z5 Y33 234 Z5 Y34 235 Z5 Y35 236 Z5 Y36 237 Z5 Y37 238 Z5 Y38 239 Z5 Y39 240 Z5 Y40 241 Z5 Y41 242 Z5 Y42 243 Z5 Y43 244 Z5 Y44 245 Z5 Y45 246 Z5 Y46 247 Z5 Y47 248 Z5 Y48 249 Z5 Y49 250 Z5 Y50 251 Z6 Y1 252 Z6 Y2 253 Z6 Y3 254 Z6 Y4 255 Z6 Y5 256 Z6 Y6 257 Z6 Y7 258 Z6 Y8 259 Z6 Y9 260 Z6 Y10 261 Z6 Y11 262 Z6 Y12 263 Z6 Y13 264 Z6 Y14 265 Z6 Y15 266 Z6 Y16 267 Z6 Y17 268 Z6 Y18 269 Z6 Y19 270 Z6 Y20 271 Z6 Y21 272 Z6 Y22 273 Z6 Y23 274 Z6 Y24 275 Z6 Y25 276 Z6 Y26 277 Z6 Y27 278 Z6 Y28 279 Z6 Y29 280 Z6 Y30 281 Z6 Y31 282 Z6 Y32 283 Z6 Y33 284 Z6 Y34 285 Z6 Y35 286 Z6 Y36 287 Z6 Y37 288 Z6 Y38 289 Z6 Y39 290 Z6 Y40 291 Z6 Y41 292 Z6 Y42 293 Z6 Y43 294 Z6 Y44 295 Z6 Y45 296 Z6 Y46 297 Z6 Y47 298 Z6 Y48 299 Z6 Y49 300 Z6 Y50 301 Z7 Y1 302 Z7 Y2 303 Z7 Y3 304 Z7 Y4 305 Z7 Y5 306 Z7 Y6 307 Z7 Y7 308 Z7 Y8 309 Z7 Y9 310 Z7 Y10 311 Z7 Y11 312 Z7 Y12 313 Z7 Y13 314 Z7 Y14 315 Z7 Y15 316 Z7 Y16 317 Z7 Y17 318 Z7 Y18 319 Z7 Y19 320 Z7 Y20 321 Z7 Y21 322 Z7 Y22 323 Z7 Y23 324 Z7 Y24 325 Z7 Y25 326 Z7 Y26 327 Z7 Y27 328 Z7 Y28 329 Z7 Y29 330 Z7 Y30 331 Z7 Y31 332 Z7 Y32 333 Z7 Y33 334 Z7 Y34 335 Z7 Y35 336 Z7 Y36 337 Z7 Y37 338 Z7 Y38 339 Z7 Y39 340 Z7 Y40 341 Z7 Y41 342 Z7 Y42 343 Z7 Y43 344 Z7 Y44 345 Z7 Y45 346 Z7 Y46 347 Z7 Y47 348 Z7 Y48 349 Z7 Y49 350 Z7 Y50 351 Z8 Y1 352 Z8 Y2 353 Z8 Y3 354 Z8 Y4 355 Z8 Y5 356 Z8 Y6 357 Z8 Y7 358 Z8 Y8 359 Z8 Y9 360 Z8 Y10 361 Z8 Y11 362 Z8 Y12 363 Z8 Y13 364 Z8 Y14 365 Z8 Y15 366 Z8 Y16 367 Z8 Y17 368 Z8 Y18 369 Z8 Y19 370 Z8 Y20 371 Z8 Y21 372 Z8 Y22 373 Z8 Y23 374 Z8 Y24 375 Z8 Y25 376 Z8 Y26 377 Z8 Y27 378 Z8 Y28 379 Z8 Y29 380 Z8 Y30 381 Z8 Y31 382 Z8 Y32 383 Z8 Y33 384 Z8 Y34 385 Z8 Y35 386 Z8 Y36 387 Z8 Y37 388 Z8 Y38 389 Z8 Y39 390 Z8 Y40 391 Z8 Y41 392 Z8 Y42 393 Z8 Y43 394 Z8 Y44 395 Z8 Y45 396 Z8 Y46 397 Z8 Y47 398 Z8 Y48 399 Z8 Y49 400 Z8 Y50 401 Z9 Y1 402 Z9 Y2 403 Z9 Y3 404 Z9 Y4 405 Z9 Y5 406 Z9 Y6 407 Z9 Y7 408 Z9 Y8 409 Z9 Y9 410 Z9 Y10 411 Z9 Y11 412 Z9 Y12 413 Z9 Y13 414 Z9 Y14 415 Z9 Y15 416 Z9 Y16 417 Z9 Y17 418 Z9 Y18 419 Z9 Y19 420 Z9 Y20 421 Z9 Y21 422 Z9 Y22 423 Z9 Y23 424 Z9 Y24 425 Z9 Y25 426 Z9 Y26 427 Z9 Y27 428 Z9 Y28 429 Z9 Y29 430 Z9 Y30 431 Z9 Y31 432 Z9 Y32 433 Z9 Y33 434 Z9 Y34 435 Z9 Y35 436 Z9 Y36 437 Z9 Y37 438 Z9 Y38 439 Z9 Y39 440 Z9 Y40 441 Z9 Y41 442 Z9 Y42 443 Z9 Y43 444 Z9 Y44 445 Z9 Y45 446 Z9 Y46 447 Z9 Y47 448 Z9 Y48 449 Z9 Y49 450 Z9 Y50 451 Z10 Y1 452 Z10 Y2 453 Z10 Y3 454 Z10 Y4 455 Z10 Y5 456 Z10 Y6 457 Z10 Y7 458 Z10 Y8 459 Z10 Y9 460 Z10 Y10 461 Z10 Y11 462 Z10 Y12 463 Z10 Y13 464 Z10 Y14 465 Z10 Y15 466 Z10 Y16 467 Z10 Y17 468 Z10 Y18 469 Z10 Y19 470 Z10 Y20 471 Z10 Y21 472 Z10 Y22 473 Z10 Y23 474 Z10 Y24 475 Z10 Y25 476 Z10 Y26 477 Z10 Y27 478 Z10 Y28 479 Z10 Y29 480 Z10 Y30 481 Z10 Y31 482 Z10 Y32 483 Z10 Y33 484 Z10 Y34 485 Z10 Y35 486 Z10 Y36 487 Z10 Y37 488 Z10 Y38 489 Z10 Y39 490 Z10 Y40 491 Z10 Y41 492 Z10 Y42 493 Z10 Y43 494 Z10 Y44 495 Z10 Y45 496 Z10 Y46 497 Z10 Y47 498 Z10 Y48 499 Z10 Y49 500 Z10 Y50 501 Z11 Y1 502 Z11 Y2 503 Z11 Y3 504 Z11 Y4 505 Z11 Y5 506 Z11 Y6 507 Z11 Y7 508 Z11 Y8 509 Z11 Y9 510 Z11 Y10 511 Z11 Y11 512 Z11 Y12 513 Z11 Y13 514 Z11 Y14 515 Z11 Y15 516 Z11 Y16 517 Z11 Y17 518 Z11 Y18 519 Z11 Y19 520 Z11 Y20 521 Z11 Y21 522 Z11 Y22 523 Z11 Y23 524 Z11 Y24 525 Z11 Y25 526 Z11 Y26 527 Z11 Y27 528 Z11 Y28 529 Z11 Y29 530 Z11 Y30 531 Z11 Y31 532 Z11 Y32 533 Z11 Y33 534 Z11 Y34 535 Z11 Y35 536 Z11 Y36 537 Z11 Y37 538 Z11 Y38 539 Z11 Y39 540 Z11 Y40 541 Z11 Y41 542 Z11 Y42 543 Z11 Y43 544 Z11 Y44 545 Z11 Y45 546 Z11 Y46 547 Z11 Y47 548 Z11 Y48 549 Z11 Y49 550 Z11 Y50

[0045] Those produced by substituting all hydrogen atoms in Compounds 1 to 550 with deuterium atoms are exemplified here as Compounds 551 to 1100.

[0046] In one aspect of the present invention, the compound represented by the general formula (1) is selected from Compounds 1 to 1100. In one aspect of the present invention, the compound is selected from Compounds 1 to 50, and 551 to 600. In one aspect of the present invention, the compound is selected from Compounds 51 to 100, 201 to 250, 401 to 450, 601 to 650, 751 to 800, and 951 to 1000. In one aspect of the present invention, the compound is selected from Compounds 101 to 200, 251 to 350, 451 to 550, 651 to 750, 801 to 900, and 1001 to 1100. In one aspect of the present invention, the compound is selected from Compounds 151 to 200, 301 to 350, 501 to 550, 701 to 750, 851 to 900, and 1051 to 1100.

[0047] In the compound represented by the general formula (1), Z and Y bond via the para-position of the benzene ring, as shown in the general formula (1a). The compound represented by the general formula (1) tends to be superior to the compound where Z and Y bond via the meta-position.

[0048] In the compound represented by the general formula (1), Z of the general formula (1a) is a substituted or unsubstituted dibenzofuryl group bonding at the 2-position. The compound represented by the general formula (1) tends to be superior to the compound where Z is a substituted or unsubstituted dibenzofuryl group bonding to the other position (for example, the 4-position).

[0049] In the compound represented by the general formula (1), Y of the general formula (1a) is a group fused with a benzofuro structure or a benzothieno structure at the specific position of the carbazole ring. The compound represented by the general formula (1) tends to be superior to the compound where Y is a group fused with a benzofuro structure or a benzothieno structure at a different position of the carbazole ring.

[0050] The compound represented by the general formula (1) can be synthesized using a known synthesis method. For example, the compound represented by the general formula (1a) can be readily synthesized by coupling ZC.sub.6H.sub.5Br and HY according to the following reaction formula. Specifically, the compound can be synthesized by reacting ZC.sub.6H.sub.5Br and an equimolar amount of HY, for example, in the presence of tris(dibenzylideneacetone)dipalladium(0), tri-tert-butylphosphonium tetrafluoroborate and sodium tert-butoxide. As the solvent, for example, toluene can be used, and the reaction can be promoted by refluxing for one day. The resultant product is extracted with an organic solvent, and purified by silica gel column chromatography and recrystallization to give the intended compound having a high purity.

##STR00013##

[Organic Semiconductor Device]

[0051] The compound represented by the general formula (1) can be favorably applied to an organic semiconductor device. For example, a CMOS (complementary metal-oxide film semiconductor) or the like using the compound represented by the general formula (1) can be produced. In some embodiments of the present disclosure, an organic optical device such as an organic electroluminescent device or a solid-state imaging device (for example, a CMOS image sensor) can be produced by using the compound represented by the general formula (1). Above all, the compound represented by the general formula (1) can be used for an organic light emitting device such as an organic electroluminescent device (organic EL device). In particular, the compound represented by the general formula (1) of the present invention can be effectively used as an electron barrier material for an organic light emitting device. In particular, by using the compound represented by the general formula (1) of the present invention in an electron barrier layer, the device life can be prolonged.

[0052] The organic electroluminescent device has a structure in which at least an anode, a cathode, and an organic layer between the anode and the cathode are formed. The organic layer includes at least a light emitting layer, and preferably has at least one organic layer (especially electron barrier layer) in addition to the light emitting layer. The organic layer to constitute the organic electroluminescent device includes a hole transport layer, a hole injection layer, an electron barrier layer, a hole barrier layer, an electron injection layer, an electron transport layer, an exciton barrier layer, an underlayer for the light emitting layer, and the like. The hole transport layer can be a hole injection transport layer having a hole injection function, and the electron transport layer can be an electron injection transport layer having an electron injection function.

[0053] In the following, the constituent members and layers of the organic electroluminescent device are described. The description of the substrate and the light emitting layer can apply also to the substrate and the light emitting layer of an organic photoluminescent device.

(Electron Barrier Layer)

[0054] In one preferred aspect of the present invention, the compound represented by the general formula (1) is used for the electron barrier layer of an organic electroluminescent device. The electron barrier layer can contain only the compound represented by the general formula (1), or can additionally contain any other compound than the compound represented by the general formula (1). The concentration of the compound represented by the general formula (1) in the electron barrier layer is preferably 50% by weight or more, more preferably 90% by weight or more, and can be, for example, 99% by weight or more, and can be 99.9% by weight or more. The thickness of the electron barrier layer is preferably 1 nm or more, more preferably 3 nm or more, and for example, can be 5 nm or more, or can be, for example, 10 nm or more. The thickness of the electron barrier layer is preferably less than 30 nm, more preferably less than 20 nm, and for example, can be 15 nm. The thickness of the electron barrier layer is preferably smaller than the thickness of the light emitting layer. The thickness of the electron barrier layer is preferably one-second of the thickness of the light emitting layer or less, more preferably one-third or less, and for example can be one-fourth or less. In addition, it is preferably one-twentieth or more, and for example can be one-tenth or more, or for example can be one-sixth or more.

[0055] The electron barrier layer containing the compound represented by the general formula (1) is preferably arranged between the light emitting layer and the anode. In one aspect of the present invention, the light emitting layer and the electron barrier layer are laminated so as to be in direct contact with each other.

[0056] In one aspect of the present invention, the device includes a laminate structure of an electron barrier layer containing the compound represented by the general formula (1), an underlayer, and a light emitting layer laminated in that order from the anode side. The electron barrier layer and the underlayer are laminated so as to be in direct contact with each other, and the underlayer and the light emitting layer are laminated so as to be in direct contact with each other, but the electron barrier layer and the light emitting layer are not in contact with each other.

(Underlayer)

[0057] The underlayer is formed for the purpose of improving the orientation of the light emitting layer and the like, and is a layer containing a hole transporting material. In one aspect of the present invention, the underlayer contains a compound having a partial structure common to the compound contained in the light emitting layer. The term common partial structure as used herein means that a partial structure composed of 12 or more atoms other than a hydrogen atom and a deuterium atom is in common, and a partial structure composed of 16 or more atoms other than a hydrogen atom and a deuterium atom is preferably in common, and for example, a partial structure composed of 20 or more atoms other than a hydrogen atom and a deuterium atom can be in common. In one aspect of the present invention, the underlayer contains a compound that is the same as the compound contained in the light emitting layer. In one aspect of the present invention, the underlayer contains only a compound that is the same as the compound contained in the light emitting layer. In one aspect of the present invention, the underlayer contains a compound that is the same as the host material contained in the light emitting layer. The thickness of the underlayer is preferably 1 nm or more, more preferably 3 nm or more, and for example, can be 5 nm or more. The thickness of the adjacent layer is preferably less than 30 nm, more preferably less than 20 nm, and for example, can be 10 nm or less, or can be 7 nm or less. The thickness of the underlayer is preferably smaller than the thickness of the light emitting layer. The thickness of the underlayer is preferably one-second of the thickness of the light emitting layer or less, more preferably one-third or less, and for example, can be one-fourth or less. In addition, it is preferably one-twentieth or more, and for example, can be one-tenth or more. The thickness of the underlayer is preferably smaller than the thickness of the electron barrier layer. The thickness of the underlayer can be, for example, three-fourth of the thickness of the electron barrier layer or less, can be, for example, two-third or less, or can be, for example, one-second or less. In addition, it is preferably one-twentieth or more, and for example, can be one-tenth or more, or for example, can be one-fourth or more.

(Light Emitting Layer)

[0058] The light emitting layer is a layer where holes and electrons injected from the anode and the cathode, respectively, are recombined to form excitons, and then emit light. The light emitting layer contains at least a light emitting material.

[0059] In order that an organic electroluminescent device can express a high light emission efficiency, it is important that the singlet excitons and the triplet excitons in the light emitting material are confined in the light emitting material. Accordingly, it is preferable to use a host material in addition to the light emitting material in the light emitting layer. As the host material, usable is an organic compound having a higher excited singlet energy than that of the light emitting material in the present invention, and preferably used here is an organic compound whose excited singlet energy and excited triplet energy are both higher than those of the light emitting material. Using a host material, the singlet excitons and the triplet excitons formed in the light emitting material can be confined in the molecule of the light emitting material, and light emission efficiency can be sufficiently expressed. Naturally, even if the singlet excitons and the triplet excitons could not be sufficiently confined, a high light emission efficiency can be attained in some cases, and therefore, a host material capable of expressing a high light emission efficiency can be used in the present invention with no specific limitation. In the organic electroluminescent device of the present invention, the maximum amount of light emitted from the device is light emitted from the light emitting material contained in the light emitting layer. The light emission includes fluorescent light emission and can contain delayed fluorescence. However, the host material can partly or partially emit light.

[0060] In the case of using a host material, the concentration of the light emitting material in the light emitting layer is preferably 0.1% by weight or more, more preferably 1% by weight or more, and is preferably 50% by weight or less, more preferably 20% by weight or less, further preferably 10% by weight or less.

[0061] An assist dopant can be used in the light emitting layer. In that case, the light emitting layer is composed of a host material, an assist dopant and a light emitting material. Here, as the host material, used is one having a higher lowest excited singlet energy than that of the assist dopant, and as the light emitting material, used is one having a lower lowest excited singlet energy than that of the assist dopant. In the present invention, it is especially preferable to use a delayed fluorescent material as the assist dopant. Delayed fluorescence means fluorescence which a compound having been in an excited state emits after the compound has undergone reverse intersystem crossing from an excited triplet state to an excited singlet state and when it returns back from the excited singlet state to a ground state, and is fluorescence observed later than fluorescence (instantaneous fluorescence) from the excited singlet state that has directly transitioned from the ground state. In the present invention, in the case where a transient decay curve of light emission of a thin film containing a targeted compound is measured at 300K, when a light emission component having a long light emission lifetime (delayed fluorescence) is observed apart from a light emission component having a short light emission lifetime (instantaneous fluorescence), that targeted compound is a delayed fluorescent material. The delayed fluorescent material is preferably a thermal activation-type delayed fluorescent material that can undergo reverse intersystem crossing by absorption of thermal energy. The fact that the fluorescent material is a thermal activation-type delayed fluorescent material can be confirmed by the fact that the light emission lifetime of the material to be determined by measurement of the transient decay curve of light emission thereof becomes long depending on the measurement temperature. Using a delayed fluorescent material as an assist dopant, the energy of the excited singlet state formed by direct transition from the ground state of the assist dopant and the excited singlet energy by reverse intersystem crossing thereof can efficiently move to a light emitting material to thereby effectively assist the light emission of the light emitting material.

[0062] In the case where the light emitting layer is composed of a host material, an assist dopant and a light emitting material, the concentration of the assist dopant in the light emitting layer is preferably smaller than the content of the host material therein. Specifically, when the total weight of the content of the host material, the content of the assist dopant, and the content of the light emitting layer is 100% by weight, the content of the host material is preferably 15% by weight or more and 99.9% by weight or less, the content of the assist dopant is preferably 5.0% by weight or more and 50% by weight or less, and the content of the light emitting material is preferably 0.5% by weight or more and 5.0% by weight or less.

[0063] In one aspect of the present invention, the light emitting layer does not contain an inorganic compound. Also in one aspect of the present invention, the light emitting layer does not contain a metal atom. In one aspect of the present invention, phosphorescence is not observed from the light emitting layer at 300K.

[0064] The host material used in the light emitting layer is preferably an organic compound having a hole transporting ability and an electron transporting ability, preventing the light emission from being a longer wavelength, and having a high glass transition temperature. In one aspect of the present invention, a compound containing a carbazole structure is preferably selected as the host material. In one preferred aspect of the present invention, a compound containing at least two structures selected from the group consisting of a carbazole structure, a dibenzofuran structure and a dibenzothiophene structure, for example, containing two such structures, or containing three such structures can be selected as the host material. In one preferred aspect of the present invention, a compound containing a 1,3-phenylene structure can be selected as the host material. In one preferred aspect of the present invention, a compound containing a biphenylene structure can be selected as the host material. In one preferred aspect of the present invention, a compound having 5 to 8 benzene rings in the molecule can be selected as the host material, and for example, a compound having 5 benzene rings can be selected, a compound having 6 benzene rings can be selected, or a compound having 7 benzene rings can be selected.

[0065] Compounds preferably usable as the host material are shown below, but the host material that can be adopted in the present invention is not construed as limiting to the following specific examples.

##STR00014## ##STR00015## ##STR00016## ##STR00017## ##STR00018## ##STR00019## ##STR00020## ##STR00021## ##STR00022## ##STR00023## ##STR00024## ##STR00025##

[0066] In the light emitting layer, a delayed fluorescent material can be used as the light emitting material or an assist dopant. For the light emitting material and the assist dopant, different delayed fluorescent materials can be used. The delayed fluorescent material generally gives fluorescence that has an emission lifetime of 100 ns (nanoseconds) or longer, when the emission lifetime thereof is measured with a fluorescence lifetime measuring system (for example, a streak camera system by Hamamatsu Photonics K.K.). The delayed fluorescent material is preferably such that the difference E.sub.ST between the lowest excited singlet energy and the lowest excited triplet energy at 77K is 0.3 eV or less, more preferably 0.25 eV or less, further preferably 0.2 eV or less, still further preferably 0.15 eV or less, still further more preferably 0.1 eV or less, still further more preferably 0.07 eV or less, still further more preferably 0.05 eV or less, still further more preferably 0.03 eV or less, particularly preferably 0.01 eV or less. When E.sub.ST is small, reverse intersystem crossing from an excited triplet state to an excited singlet state can readily occur through thermal energy absorption, and therefore the compound of the type can function as a thermal activation type delayed fluorescent material. A thermal activation type delayed fluorescent material can absorb heat generated by a device to relatively readily undergo reverse intersystem crossing from an excited triplet state to an excited singlet state, and can make the excited triplet energy efficiently contribute toward light emission.

[0067] In the present invention, the lowest excited singlet energy (E.sub.S1) and the lowest excited triplet energy (E.sub.T1) of a compound are determined according to the following process. E.sub.ST is a value determined by calculating E.sub.S1E.sub.T1.

(1) Lowest Excited Singlet Energy (E.SUB.S1.)

[0068] A thin film or a toluene solution (concentration: 10.sup.5 mol/L) of the targeted compound is prepared as a measurement sample. The fluorescent spectrum of the sample is measured at room temperature (300 K). For the fluorescent spectrum, the emission intensity is on the vertical axis and the wavelength is on the horizontal axis. A tangent line is drawn to the rising of the emission spectrum on the short wavelength side, and the wavelength value edge [nm] at the intersection between the tangent line and the horizontal axis is read. The wavelength value is converted into an energy value according to the following conversion expression to calculate E.sub.S1.

Conversion Expression: E.sub.S1 [eV]=1239.85/edge

[0069] For the measurement of the emission spectrum in Examples given below, an LED light source (by Thorlabs Corporation, M300L4) was used as an excitation light source along with a detector (by Hamamatsu Photonics K.K., PMA-12 Multichannel Spectroscope C10027-01).

(2) Lowest Excited Triplet Energy (E.SUB.T1.)

[0070] The same sample as that for measurement of the lowest excited singlet energy (E.sub.S1) is cooled to 77 [K] with liquid nitrogen, and the sample for phosphorescence measurement is irradiated with excitation light (300 nm), and using the detector, the phosphorescence thereof is measured. The light emission after 100 milliseconds from irradiation with the excitation light is drawn as a phosphorescent spectrum. A tangent line is drawn to the rising of the phosphorescent spectrum on the short wavelength side, and the wavelength value edge [nm] at the intersection between the tangent line and the horizontal axis is read. The wavelength value is converted into an energy value according to the following conversion expression to calculate E.sub.T1.

Conversion Expression: E.sub.T1 [eV]=1239.85/edge

[0071] The tangent line to the rising of the phosphorescent spectrum on the short wavelength side is drawn as follows. While moving on the spectral curve from the short wavelength side of the phosphorescent spectrum toward the local maximum value on the shortest wavelength side among the local maximum values of the spectrum, a tangent line at each point on the curve toward the long wavelength side is taken into consideration. With rising thereof(that is, with increase in the vertical axis), the inclination of the tangent line increases. The tangent line drawn at the point at which the inclination value has a local maximum value is referred to as the tangent line to the rising on the short wavelength side of the phosphorescent spectrum.

[0072] The local maximum point having a peak intensity of 10% or less of the maximum peak intensity of the spectrum is not included in the local maximum value on the above-mentioned shortest wavelength side, and the tangent line drawn at the point which is closest to the local maximum value on the shortest wavelength side and at which the inclination value has a local maximum value is referred to as the tangent line to the rising on the short wavelength side of the phosphorescent spectrum.

[0073] Preferably, the delayed fluorescent material does not contain a metal atom. For example, as the delayed fluorescent material, a compound including an atom selected from the group consisting of a carbon atom, a hydrogen atom, a deuterium atom, a nitrogen atom, an oxygen atom, and a sulfur atom can be selected. For example, as the delayed fluorescent material, a compound composed of a carbon atom, a hydrogen atom and a nitrogen atom can be selected.

[0074] A typical delayed fluorescent material includes a compound having a structure in which 1 or 2 acceptor groups and at least one donor group bond to a benzene ring. Preferred examples of the acceptor group include a cyano group, and a group that contains a heteroaryl ring containing a nitrogen atom as a ring skeleton-constituting atom such as a triazinyl ring. Preferred examples of the donor group include a substituted or unsubstituted carbazol-9-yl group. Examples thereof include a compound in which at least three substituted or unsubstituted carbazol-9-yl groups bond to a benzene ring, and a compound in which a 5-membered ring moiety of a substituted or unsubstituted benzofuran ring, a substituted or unsubstituted benzothiophene ring, a substituted or unsubstituted indole ring, a substituted or unsubstituted indene ring, or a substituted or unsubstituted silaindene ring is fused to at least one of the two benzene rings constituting a carbazol-9-yl group.

[0075] In one preferred aspect of the present invention, a compound represented by the following general formula (4) is used as the delayed fluorescent material.

##STR00026##

[0076] In the general formula (4), one of R.sup.21 to R.sup.23 represents a cyano group or a group represented by the following general formula (5), the remaining two of R.sup.21 to R.sup.23 and at least one of R.sup.24 and R.sup.25 each represent a group represented by the following general formula (6), the remaining R.sup.21 to R.sup.25 each represent a hydrogen atom or a substituent, provided that the substituent referred to here is not a cyano group, the group represented by the following general formula (5) and the group represented by the following general formula (6).

##STR00027##

[0077] In the general formula (5), L.sup.1 represents a single bond or a divalent linking group, R.sup.31 and R.sup.32 each independently represents a hydrogen atom or a substituent, * indicates a bonding site.

##STR00028##

[0078] In the general formula (6), L.sup.2 represents a single bond or a divalent linking group, R.sup.33 and R.sup.34 each independently represents a hydrogen atom or a substituent, * indicates a bonding site.

[0079] In one preferred aspect of the present invention, R.sup.22 is a cyano group. In one preferred aspect of the present invention, R.sup.22 is a group represented by the general formula (5). In one aspect of the present invention, R.sup.21 is a cyano group, or a group represented by the general formula (5). In one aspect of the present invention, R.sup.23 is a cyano group, or a group represented by the general formula (5). In one aspect of the present invention, one of R.sup.21 to R.sup.23 is a cyano group. In one aspect of the present invention, one of R.sup.21 to R.sup.23 is a group represented by the general formula (5).

[0080] In one preferred aspect of the present invention, L.sup.1 in the general formula (5) is a single bond. In one aspect of the present invention, L.sup.1 is a divalent linking group, and is preferably a substituted or unsubstituted arylene group or a substituted or unsubstituted heteroarylene group, more preferably a substituted or unsubstituted arylene group, further preferably a substituted or unsubstituted 1,4-phenylene group (in which the substituent is, for example, an alkyl group having 1 to 3 carbon atoms).

[0081] In one aspect of the present invention, R.sup.31 and R.sup.32 in the general formula (5) are each independently one group selected from the group consisting of an alkyl group (for example, having 1 to 40 carbon atoms), an aryl group (for example, having 6 to 30 carbon atoms), a heteroaryl group (for example, having 5 to 30 ring skeleton-constituting atoms), an alkenyl group (for example, having 2 to 40 carbon atoms) and an alkynyl group (for example, having 2 to 40 carbon atoms), or a group formed by combining at least two such groups (hereinunder these groups are referred to as groups of Substituent Group A). In one preferred aspect of the present invention, R.sup.31 and R.sup.32 are each independently a substituted or unsubstituted aryl group (for example, having 6 to 30 carbon atoms), and the substituent for the aryl group includes the groups of Substituent Group A. In one preferred aspect of the present invention, R.sup.31 and R.sup.32 are the same.

[0082] In one preferred aspect of the present invention, L.sup.2 in the general formula (6) is a single bond. In one aspect of the present invention, L.sup.2 is a divalent linking group, and is preferably a substituted or unsubstituted arylene group or a substituted or unsubstituted heteroarylene group, more preferably a substituted or unsubstituted arylene group, further preferably a substituted or unsubstituted 1,4-phenylene group (in which the substituent is, for example, an alkyl group having 1 to 3 carbon atoms).

[0083] In one aspect of the present invention, R.sup.33 and R.sup.34 in the general formula (6) are each independently a substituted or unsubstituted alkyl group (for example, having 1 to 40 carbon atoms), a substituted or unsubstituted alkenyl group (for example, having 2 to 40 carbon atoms), a substituted or unsubstituted aryl group (for example, having 6 to 30 carbon atoms), or a substituted or unsubstituted heteroaryl group (for example, having 5 to 30 carbon atoms). The substituent for the alkyl group, the alkenyl group, the aryl group and the heteroaryl group as referred to herein includes one group selected from the group consisting of a hydroxy group, a halogen atom (for example, a fluorine atom, a chlorine atom, a bromine atom, an iodine atom), an alkyl group (for example, having 1 to 40 carbon atoms), an alkoxy group (for example, having 1 to 40 carbon atoms), an alkylthio group (for example, having 1 to 40 carbon atoms), an aryl group (for example, having 6 to 30 carbon atoms), an aryloxy group (for example, having 6 to 30 carbon atoms), an arylthio group (for example, having 6 to 30 carbon atoms), a heteroaryl group (for example, having 5 to 30 ring skeleton-constituting atoms), a heteroaryloxy group (for example, having 5 to 30 ring skeleton-constituting atoms), a heteroarylthio group (for example, having 5 to 30 ring skeleton-constituting atoms), an acyl group (for example, having 2 to 40 carbon atoms), an alkenyl group (for example, having 2 to 40 carbon atoms), an alkynyl group (for example, having 2 to 40 carbon atoms), an alkoxycarbonyl group (for example, having 2 to 40 carbon atoms), an aryloxycarbonyl group (for example, having 7 to 40 carbon atoms), a heteroaryloxycarbonyl group (for example, having 7 to 40 carbon atoms), a silyl group (for example, a trialkylsilyl group having 3 to 40 carbon atoms), a nitro group and a cyano group, or a group formed by combining at least two such groups (hereinunder these groups are referred to as groups of Substituent Group B).

[0084] R.sup.33 and R.sup.34 can bond to each other via a single bond or a linking group to form a cyclic structure. In particular, in the case were R.sup.33 and R.sup.34 are aryl groups, preferably, they bond to each other via a single bond or a linking group to form a cyclic structure. The linking group as referred to herein includes O, S, N(R.sup.35), C(R.sup.36)(R.sup.37), and C(O), preferably O, S, N(R.sup.35), and C(R.sup.36)(R.sup.37), more preferably O, S, and N(R.sup.35). R.sup.35 to R.sup.37 each independently represent a hydrogen atom or a substituent. For the substituent, the groups of the above Substituent Group A can be selected, or the groups of the above Substituent Group B can be selected, and preferably, the substituent is one group selected from the group consisting of an alkyl group having 1 to 10 carbon atoms and an aryl group having 6 to 14 carbon atoms, or a group formed by combining at least two such groups.

[0085] The group represented by the general formula (6) is preferably a group represented by the following general formula (7).

##STR00029##

[0086] In the general formula (7), L.sup.11 represents a single bond or a divalent linking group. Regarding the description and the preferred range of L.sup.11, reference can be made to the description and the preferred range of L.sup.2 described hereinabove.

[0087] In the general formula (7), R.sup.41 to R.sup.48 each independently represent a hydrogen atom or a substituent. R.sup.41 and R.sup.42, R.sup.42 and R.sup.43, R.sup.43 and R.sup.44, R.sup.44 and R.sup.45, R.sup.45 and R.sup.46, R.sup.46 and R.sup.47, and R.sup.47 and R.sup.48, each can bond to each other to form a cyclic structure. The cyclic structure to be formed by bonding to each other can be an aromatic ring or an aliphatic ring, or can contain a hetero atom, and further, the cyclic structure can also be a fused ring of two or more rings. Here the hetero atom is preferably selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom. Examples of the cyclic structure to be formed include a benzene ring, a naphthalene ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a pyrrole ring, an imidazole ring, a pyrazole ring, an imidazoline ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, a cyclohexadiene ring, a cyclohexene ring, a cyclopentaene ring, a cycloheptatriene ring, a cycloheptadiene ring, a cycloheptaene ring, a furan ring, a thiophene ring, a naphthyridine ring, a quinoxaline ring, and a quinoline ring. Many rings can be fused to form a ring such as a phenanthrene ring or a triphenylene ring. The number of the rings contained in the group represented by the general formula (7) can be selected from the range of 3 to 5, or can be selected from the range of 5 to 7.

[0088] The substituent which R.sup.41 to R.sup.48 can take includes the groups of the above-mentioned Substituent Group B, and is preferably an unsubstituted alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 10 carbon atoms optionally substituted with an unsubstituted alkyl group having 1 to 10 carbon atoms. In one preferred aspect of the present invention, R.sup.41 to R.sup.48 each are a hydrogen atom or an unsubstituted alkyl group having 1 to 10 carbon atoms. In one preferred aspect of the present invention, R.sup.41 to R.sup.48 each are a hydrogen atom or an unsubstituted aryl group having 6 to 10 carbon atoms. In one preferred aspect of the present invention, R.sup.41 to R.sup.48 are all hydrogen atoms.

[0089] In the general formula (7), * indicates a bonding site.

[0090] In one preferred aspect of the present invention, an azabenzene derivative is used as the delayed fluorescent material. In one preferred aspect of the present invention, the azabenzene derivative has an azabenzene structure in which three ring skeleton-constituting carbon atoms of the benzene ring are substituted with nitrogen atoms. For example, an azabenzene derivative having a 1,3,5-triazine structure can be preferably selected. In one preferred aspect of the present invention, the azabenzene derivative has an azabenzene structure in which two ring skeleton-constituting carbon atoms of the benzene ring are substituted with nitrogen atoms. For example, it includes an azabenzene derivative having a pyridazine structure, a pyrimidine structure, or a pyrazine structure, and an azabenzene derivative having a pyrimidine structure can be preferably selected. In one aspect of the present invention, the azabenzene derivative has a pyridine structure in which one ring skeleton-constituting carbon atom of the benzene ring is substituted with a nitrogen atom.

[0091] In one preferred aspect of the present invention, a compound represented by the following general formula (8) is used as the delayed fluorescent material.

##STR00030##

[0092] In the general formula (8), at least one of Y.sup.1, Y.sup.2 and Y.sup.3 is a nitrogen atom and the remainder represents a methine group. In one aspect of the present invention, Y.sup.1 is a nitrogen atom, and Y.sup.2 and Y.sup.3 are methine groups. Preferably, Y.sup.1 and Y.sup.2 are nitrogen atoms, and Y.sup.3 is a methine group. More preferably, Y.sup.1 to Y.sup.3 are all nitrogen atoms.

[0093] In the general formula (8), Z.sup.1 to Z.sup.3 each independently represent a hydrogen atom or a substituent, but at least one is a donor substituent. The donor substituent means a group having a negative Hammett's p value. Preferably, at least one of Z.sup.1 to Z.sup.3 is a group containing a diarylamino structure (in which the two aryl groups bonding to the nitrogen atom can bond to each other), and is more preferably a group represented by the above general formula (6), for example, a group represented by the above general formula (7). In one aspect of the present invention, only one of Z.sup.1 to Z.sup.3 is a group represented by the general formula (6) or (7). In one aspect of the present invention, only two of Z.sup.1 to Z.sup.3 are each independently a group represented by the general formula (6) or (7). In one aspect of the present invention, all of Z.sup.1 to Z.sup.3 are each independently a group represented by the general formula (6) or (7). For details and preferable ranges of the general formula (6) and the general formula (7), the corresponding descriptions given above can be referred to. The remaining Z.sup.1 to Z.sup.3 that are not the groups represented by the general formula (6) and the general formula (7) each are preferably a substituted or unsubstituted aryl group (for example, having 6 to 40 carbon atoms, preferably 6 to 20 carbon atoms), and examples of the substituent for the aryl group as referred to herein include one group selected from the group consisting of an aryl group (for example, having 6 to 20 carbon atoms, preferably 6 to 14 carbon atoms) and an alkyl group (for example, having 1 to 20 carbon atoms, preferably 1 to 6 carbon atoms), and a group formed by combining at least two such groups. In one aspect of the present invention, the general formula (8) does not include a cyano group.

[0094] In one preferred aspect of the present invention, a compound represented by the following general formula (9) is used as the delayed fluorescent material.

##STR00031##

[0095] In the general formula (9), Ar.sup.1 forms a cyclic structure optionally substituted with the following A.sup.1 and D.sup.1, and represents a benzene ring, a naphthalene ring, an anthracene ring or a phenanthrene ring. Ar.sup.2 and Ar.sup.3 each can form a cyclic structure, and in the case of forming a cyclic structure, they represent a benzene ring, a naphthalene ring, a pyridine ring, or a benzene ring substituted with a cyano group. m1 represents an integer of any of 0 to 2, and m2 represents an integer of any of 0 to 1. A.sup.1 represents a cyano group, a phenyl group, a pyrimidyl group, a triazyl group, or a benzonitrile group. D.sup.1 represents a substituted or unsubstituted 5H-indolo[3,2,1-de]phenazin-5-yl group, or a substituted or unsubstituted hetero ring-fused carbazolyl group not containing a naphthalene structure, and in the case where the general formula (9) has plural D.sup.1's, they can be the same or different. The substituents for D.sup.1 can bond to each other to form a cyclic structure.

[0096] Compounds represented by the following general formula (E1) are further preferred delayed fluorescent materials.

##STR00032##

[0097] In the general formula (E1), R.sup.1, and R.sup.3 to R.sup.16 each independently represent a hydrogen atom, a deuterium atom or a substituent. R.sup.2 represents an acceptor group, or R.sup.1 and R.sup.2 bond to each other to form an acceptor group, or R.sup.2 and R.sup.3 bond to each other to form an acceptor group. R.sup.3 and R.sup.4, R.sup.4 and R.sup.5, R.sup.5 and R.sup.6, R.sup.6 and R.sup.7, R.sup.7 and R.sup.8, R.sup.9 and R.sup.10, R.sup.10 and R.sup.11, R.sup.11 and R.sup.12, R.sup.12 and R.sup.13, R.sup.13 and R.sup.14, R.sup.14 and R.sup.15, and R.sup.15 and R.sup.16 each can bond to each other to form a cyclic structure. X.sup.1 represents O or NR, and R represents a substituent. Of X.sup.2 to X.sup.4, at least one of X.sup.3 and X.sup.4 is O or NR, and the remainder can be O or R, or unlinked. When not linked, both ends each independently represent a hydrogen atom, a deuterium atom or a substituent. In the general formula (E1), CR.sup.1, CR.sup.3, CR.sup.4, CR.sup.5, CR.sup.6, CR.sup.7, CR.sup.8, CR.sup.9, CR.sup.10, CR.sup.11, CR.sup.12, CR.sup.13, CR.sup.14, CR.sup.15, and CR.sup.16 can be substituted with N.

[0098] Compounds represented by the following general formula (E2) are further preferred delayed fluorescent materials.

##STR00033##

[0099] In the general formula (E2), R.sup.1 and R.sup.2 each independently represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group, R.sup.3 to R.sup.16 each independently represent a hydrogen atom, a deuterium atom or a substituent. R.sup.1 and R.sup.3, R.sup.3 and R.sup.4, R.sup.4 and R.sup.5, R.sup.5 and R.sup.6, R.sup.6 and R.sup.7, R.sup.7 and R.sup.8, R.sup.8 and R.sup.9, R.sup.9 and R.sup.2, R.sup.2 and R.sup.10, R.sup.10 and R.sup.11, R.sup.11 and R.sup.12, R.sup.12 and R.sup.13, R.sup.13 and R.sup.14, R.sup.14 and R.sup.15, R.sup.15 and R.sup.16, and R.sup.16 and R.sup.1 each can bond to each other to form a cyclic structure. In the general formula (E2), CR.sup.3, CR.sup.4, CR.sup.5, CR.sup.6, CR.sup.7, CR.sup.8, CR.sup.9, CR.sup.10, CR.sup.11, CR.sup.12, CR.sup.13, CR.sup.14, CR.sup.15, and CR.sup.16 can be substituted with N.

[0100] Compounds represented by the following general formula (E3) are further preferred delayed fluorescent materials.

##STR00034##

[0101] In the general formula (E3), Z.sup.1 and Z.sup.2 each independently represent a substituted or unsubstituted aromatic ring, or a substituted or unsubstituted heteroaromatic ring, and R.sup.1 to R.sup.9 each independently represent a hydrogen atom, a deuterium atom or a substituent. R.sup.1 and R.sup.2, R.sup.2 and R.sup.3, R.sup.3 and R.sup.4, R.sup.4 and R.sup.5, R.sup.5 and R.sup.6, R.sup.7 and R.sup.8 and R.sup.8 and R.sup.9 each can bond to each other to form a cyclic structure. However, at least one of the ring formed by Z.sup.1, Z.sup.2, or R.sup.1 and R.sup.2 bonding to each other, the ring formed by R.sup.2 and R.sup.3 bonding to each other, the ring formed by R.sup.4 and R.sup.5 bonding to each other, and the ring formed by R.sup.5 and R.sup.6 bonding to each other is a furan ring of a substituted or unsubstituted benzofuran, a thiophene ring of a substituted or unsubstituted benzothiophene, or a pyrrole ring of a substituted or unsubstituted indole, and at least one of R.sup.1 to R.sup.9 is a substituted or unsubstituted aryl group or an acceptor group, or at least one of Z.sup.1 and Z.sup.2 is a ring having an aryl group or an acceptor group as a substituent. Of the benzene ring skeleton-constituting carbon atoms to constitute the benzofuran ring, the benzothiophene ring, and the indole ring, a substitutable carbon atom can be substituted with a nitrogen atom. In the general formula (E3), CR.sup.1, CR.sup.2, CR.sup.3, CR.sup.4, CR.sup.5, CR.sup.6, CR.sup.7, CR.sup.8, and CR.sup.9 can be substituted with N.

[0102] Compounds represented by the following general formula (E4) are further preferred delayed fluorescent materials.

##STR00035##

[0103] In the general formula (E4), Z.sup.1 represents a furan ring fused with a substituted or unsubstituted benzene ring, a thiophene ring fused with a substituted or unsubstituted benzene ring, or an N-substituted pyrrole ring fused with a substituted or unsubstituted benzene ring, Z.sup.2 and Z.sup.3 each independently represent a substituted or unsubstituted aromatic ring, or a substituted or unsubstituted heteroaromatic ring, R.sup.1 represents a hydrogen atom, a deuterium atom, or a substituent, R.sup.2 and R.sup.3 each independently represent a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group. Z.sup.1 and R.sup.1, R.sup.2 and Z.sup.2, Z.sup.2 and Z.sup.3, and Z.sup.3 and R.sup.3 each can bond to each other to form a cyclic structure. However, at least one combination of R.sup.2 and Z.sup.2, Z.sup.2 and Z.sup.3, and Z.sup.3 and R.sup.3 bonds to each other to form a cyclic structure.

[0104] Compounds represented by the following general formula (E5) are further preferred delayed fluorescent materials.

##STR00036##

[0105] In the general formula (E5), R.sup.1 and R.sup.2 each independently represent a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group, Z.sup.1 and Z.sup.2 each independently represent a substituted or unsubstituted aromatic ring, or a substituted or unsubstituted heteroaromatic ring, R.sup.3 to R.sup.9 each independently represent a hydrogen atom, a deuterium atom or a substituent. However, at least one of R.sup.1, R.sup.2, Z.sup.1 and Z.sup.2 includes a substituted or unsubstituted benzofuran ring, a substituted or unsubstituted benzothiophene ring, or a substituted or unsubstituted indole ring. R.sup.1 and Z.sup.1, Z.sup.1 and R.sup.3, R.sup.3 and R.sup.4, R.sup.4 and R.sup.5, R.sup.5 and Z.sup.2, Z.sup.2 and R.sup.2, R.sup.2 and R.sup.6, R.sup.6 and R.sup.7, R.sup.7 and R.sup.8, R.sup.8 and R.sup.9, and R.sup.9 and R.sup.1 each can bond to each other to form a cyclic structure. Of the benzene ring skeleton-constituting carbon atoms to constitute the benzofuran ring, the benzothiophene ring, and the indole ring, a substitutable carbon atom can be substituted with a nitrogen atom. In the general formula (E5), CR.sup.3, CR.sup.4, CR.sup.5, CR.sup.6, CR.sup.7, CR.sup.8, and CR.sup.9 can be substituted with N.

[0106] Compounds represented by the following general formula (E6) are further preferred delayed fluorescent materials.

##STR00037##

[0107] In the general formula (E6), R.sup.201 to R.sup.221 each independently represent a hydrogen atom, a deuterium atom or a substituent, preferably a hydrogen atom, a deuterium atom, an alkyl group, an aryl group, or a group formed by combining an alkyl group and an aryl group. At least one combination of R.sup.201 and R.sup.202, R.sup.202 and R.sup.203, R.sup.203 and R.sup.204, R.sup.205 and R.sup.206, R.sup.206 and R.sup.207, R.sup.207 and R.sup.208, R.sup.214 and R.sup.215, R.sup.215 and R.sup.216, R.sup.216 and R.sup.217, R.sup.218 and R.sup.219, R.sup.219 and R.sup.220, and R.sup.220 and R.sup.221 each bond to each other to form a benzofuro structure or a benzothieno structure. Preferably, one or two combinations of R.sup.201 and R.sup.202, R.sup.202 and R.sup.203, R.sup.203 and R.sup.204, R.sup.205 and R.sup.206, R.sup.206 and R.sup.207 and R.sup.207 and R.sup.208, and one or two combinations of R.sup.214 and R.sup.215, R.sup.215 and R.sup.216, R.sup.216 and R.sup.217, R.sup.218 and R.sup.219, R.sup.219 and R.sup.220 and R.sup.220 and R.sup.221 bond to each other to form a benzofuro structure or a benzothieno structure. Further preferably, R.sup.203 and R.sup.204 bond to each other to form a benzofuro structure or a benzothieno structure, further preferably, R.sup.203 and R.sup.204, and R.sup.216 and R.sup.217 each bond to each other to form a benzofuro structure or a benzothieno structure. Especially preferably, R.sup.203 and R.sup.204, and R.sup.216 and R.sup.217 each bond to each other to form a benzofuro structure or a benzothieno structure, and R.sup.206 and R.sup.219 each represent a substituted or unsubstituted aryl group (preferably, a substituted or unsubstituted phenyl group, more preferably an unsubstituted phenyl group).

[0108] In the general formula (E6), R.sup.201 to R.sup.208, and R.sup.214 to R.sup.221 can be each independently a deuterium atom, but contain a structure not a hydrogen atom (.sup.1H). Specifically, in the case where R.sup.201 to R.sup.208, and R.sup.214 to R.sup.221 contain an atom having one proton, the atom contains a structure limited to a deuterium atom.

[0109] Further, compounds represented by the general formulae (1) described in Japanese Patent Application Nos. 2021-103698, 2021-103699, 2021-103700, 2021-081332, 2021-103701, 2021-151805, and 2021-188860 can be used as delayed fluorescent materials. Descriptions of these general formulae (1) and specific compounds are hereby incorporated by reference as a part of this description.

[0110] Preferred compounds usable as a delayed fluorescent material are shown below. In the structural formulae of the following exemplary compounds, t-Bu represents a tertiary butyl group (tert-butyl group).

##STR00038## ##STR00039## ##STR00040## ##STR00041## ##STR00042## ##STR00043## ##STR00044## ##STR00045## ##STR00046## ##STR00047## ##STR00048## ##STR00049## ##STR00050##

##STR00051## ##STR00052## ##STR00053## ##STR00054## ##STR00055## ##STR00056## ##STR00057## ##STR00058## ##STR00059## ##STR00060## ##STR00061## ##STR00062## ##STR00063## ##STR00064##

##STR00065## ##STR00066## ##STR00067## ##STR00068## ##STR00069## ##STR00070## ##STR00071## ##STR00072## ##STR00073## ##STR00074## ##STR00075##

##STR00076## ##STR00077##

[0111] Those produced by substituting all hydrogen atoms in the above Compounds T1 to T165 with deuterium atoms are exemplified here as T1(D) to T165(D). Those produced by substituting all hydrogen atoms in the substituted or unsubstituted carbazol-9-yl group (including those further fused with a ring) present in the above Compounds T1 to T165 with deuterium atoms are exemplified here as T1(d) to T165(d).

[0112] Any other known delayed fluorescent materials than the above can be appropriately combined and used. In addition, unknown delayed fluorescent materials can also be used.

[0113] As delayed fluorescent materials, there can be mentioned compounds included in the general formulae described in WO2013/154064, paragraphs 0008 to 0048 and 0095 to 0133; WO2013/011954, paragraphs 0007 to 0047 and 0073 to 0085; WO2013/011955, paragraphs 0007 to 0033 and 0059 to 0066; WO2013/081088, paragraphs 0008 to 0071 and 0118 to 0133; JP 2013-256490 A, paragraphs 0009 to 0046 and 0093 to 0134; JP 2013-116975 A, paragraphs 0008 to 0020 and 0038 to 0040; WO2013/133359, paragraphs 0007 to 0032 and 0079 to 0084; WO2013/161437, paragraphs 0008 to 0054 and 0101 to 0121; JP 2014-9352 A, paragraphs 0007 to 0041 and 0060 to 0069; JP 2014-9224 A, paragraphs 0008 to 0048 and 0067 to 0076; JP 2017-119663 A, paragraphs 0013 to 0025; JP 2017-119664 A, paragraphs 0013 to 0026; JP 2017-222623 A, paragraphs 0012 to 0025; JP 2017-226838 A, paragraphs 0010 to 0050; JP 2018-100411 A, paragraphs 0012 to 0043; and WO2018/047853, paragraphs 0016 to 0044; and especially, exemplary compounds therein capable of emitting delayed fluorescence. In addition, also employable here are light emitting materials capable of emitting delayed fluorescence, as described in JP 2013-253121 A, WO2013/133359, WO2014/034535, WO2014/115743, WO2014/122895, WO2014/126200, WO2014/136758, WO2014/133121, WO2014/136860, WO2014/196585, WO2014/189122, WO2014/168101, WO2015/008580, WO2014/203840, WO2015/002213, WO2015/016200, WO2015/019725, WO2015/072470, WO2015/108049, WO2015/080182, WO2015/072537, WO2015/080183, JP 2015-129240 A, WO2015/129714, WO2015/129715, WO2015/133501, WO2015/136880, WO2015/137244, WO2015/137202, WO2015/137136, WO2015/146541 and WO2015/159541. These patent publications described in these paragraphs are hereby incorporated as a part of this description by reference.

[0114] In the case where a delayed fluorescent material is used as an assist dopant in the light emitting layer, a compound having a smaller lowest excited singlet energy than the assist dopant is used as the light emitting material. Examples of the light emitting material that is used in combination with an assist dopant include compounds of a boron atom and a nitrogen atom having a multiple resonance effect, and compounds containing a fused aromatic ring structure such as anthracene, pyrene and perylene. In addition, delayed fluorescent materials exemplified hereinabove can also be used.

[0115] In one preferred aspect of the present invention, a compound represented by the following general formula (F1) is used as the light emitting material to be used in combination with an assist dopant.

##STR00078##

[0116] In the above general formula (F1), Ar.sup.1 to Ar.sup.3 are each independently an aryl ring or a heteroaryl ring, and at least one hydrogen atom in these rings can be substituted or can be fused with a ring. In the case where the hydrogen atom is substituted, preferably, it is substituted with one group selected from the group consisting of a deuterium atom, an aryl group, a heteroaryl group and an alkyl group, or a group formed by combining at least two such groups. In the case where a ring is fused, preferably, a benzene ring or a heteroaromatic ring (for example, a furan ring, a thiophene ring, and a pyrrole ring) is fused. R.sup.a and R.sup.a each independently represent a substituent, preferably one group selected from the group consisting of a deuterium atom, an aryl group, a heteroaryl group and an alkyl group, or a group formed by combining at least two such groups. R.sup.a and Ar.sup.1, Ar.sup.1 and Ar.sup.2, Ar.sup.2 and R.sup.a, R.sup.a and Ar.sup.3, and Ar.sup.3 and R.sup.a each can bond to each other to form a cyclic structure.

[0117] Preferably, the compound represented by the general formula (F1) contains at least one carbazole structure. For example, one benzene ring constituting the carbazole structure can be a ring represented by Ar.sup.1, one benzene ring constituting the carbazole structure can be a ring represented by Ar.sup.2, and one benzene ring constituting the carbazole structure can be a ring represented by Ar.sup.3. Also, a carbazolyl group can bond to at least any one of Ar.sup.1 to Ar.sup.3. For example, a substituted or unsubstituted carbazol-9-yl group can bond to the ring represented by Ar.sup.3.

[0118] A fused aromatic ring structure such as anthracene, pyrene or perylene can bond to Ar.sup.1 to Ar.sup.3. Also, the ring represented by Ar.sup.1 to Ar.sup.3 can be one ring constituting a fused aromatic ring structure. Further, at least one of R.sup.a and R.sup.a can be a group having a fused aromatic ring structure.

[0119] The compound can have plural skeletons represented by the general formula (F1). For example, the compound can have a structure where skeletons represented by the general formula (F1) bond to each other via a single bond or a linking group. Also, a structure that exhibits a multiple resonance effect formed by linking benzene rings with a boron atom, a nitrogen atom, an oxygen atom or a sulfur atom can be added to the skeleton represented by the general formula (F1).

[0120] In one preferred aspect of the present invention, a compound having a BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) structure is used as the light emitting material to be used in combination with an assist dopant. For example, a compound represented by the following general formula (F2) is used.

##STR00079##

[0121] In the general formula (F2), R.sup.1 to R.sup.7 are each independently a hydrogen atom, a deuterium atom, or a substituent. At least one of R.sup.1 to R.sup.7 is preferably a group represented by the following general formula (F3).

##STR00080##

[0122] In the general formula (F3), R.sup.11 to R.sup.15 each independently represent a hydrogen atom, a deuterium atom or a substituent, and * indicates a bonding site.

[0123] The group represented by the general formula (F3) can be one of R.sup.1 to R.sup.7 in the general formula (F2), or can be two thereof, or can be three thereof. Also, they can be at least four, and for example, four or five. In one preferred aspect of the present invention, one of R.sup.1 to R.sup.7 is a group represented by the general formula (F3). In one preferred aspect of the present invention, at least R.sup.1, R.sup.3, R.sup.5 and R.sup.7 each are a group represented by the general formula (F3). In one preferred aspect of the present invention, only R.sup.1, R.sup.3, R.sup.4, R.sup.5, and R.sup.7 are groups represented by the general formula (F3). In one preferred aspect of the present invention, R.sup.1, R.sup.3, R.sup.4, R.sup.5, and R.sup.7 are groups represented by the general formula (F3), and R.sup.2 and R.sup.4 each are a hydrogen atom, a deuterium atom, an unsubstituted alkyl group (for example, having 1 to 10 carbon atoms), or an unsubstituted aryl group (for example, having 6 to 14 carbon atoms). In one aspect of the present invention, all R.sup.1 to R.sup.7 are groups represented by the general formula (F3).

[0124] In one preferred aspect of the present invention, R.sup.1 and R.sup.7 are the same. In one preferred aspect of the present invention, R.sup.3 and R.sup.5 are the same. In one preferred aspect of the present invention, R.sup.2 and R.sup.6 are the same. In one preferred aspect of the present invention, R.sup.1 and R.sup.7 are the same, R.sup.3 and R.sup.5 are the same, and R.sup.1 and R.sup.3 differ from each other. In one preferred aspect of the present invention, R.sup.1, R.sup.3, R.sup.5 and R.sup.7 are the same. In one preferred aspect of the present invention, R.sup.1, R.sup.4 and R.sup.7 are the same, and differ from R.sup.3 and R.sup.5. In one preferred aspect of the present invention, R.sup.3, R.sup.4 and R.sup.5 are the same, and differ from R.sup.1 and R.sup.7. In one preferred aspect of the present invention, R.sup.1, R.sup.3, R.sup.5 and R.sup.7 all differ from R.sup.4.

[0125] The substituent that R.sup.11 to R.sup.15 in the general formula (F3) can take can be selected, for example, from the above Substituent Group A, or from the above Substituent Group B, or from the following Substituent Group C, or from the following Substituent Group D. In the case where a substituted amino group is selected for the substituent, it is preferably a di-substituted amino group, and the two substituents of the amino group are each independently preferably a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and especially preferably a substituted or unsubstituted aryl group (a diarylamino group). The substituent that the two aryl groups of the diarylamino group can take can be selected, for example, from the above Substituent Group A, or from the above Substituent Group B, or from the following Substituent Group C, or from the following Substituent Group D. The two aryl groups of the diarylamino group can bond to each other via a single bond or a linking group, and for the linking group as referred to here, reference can be made to the description of the linking group in R.sup.33 and R.sup.34. Specific examples of the diarylamino group include a substituted or unsubstituted carbazol-9-yl group. Examples of the substituted or unsubstituted carbazol-9-yl group include a group of the general formula (9) where L.sup.11 is a single bond.

[0126] In one preferred aspect of the present invention, only R.sup.13 in the general formula (F3) is a substituent, and R.sup.11, R.sup.12, R.sup.14 and R.sup.15 therein are hydrogen atoms. In one preferred aspect of the present invention, only R.sup.11 in the general formula (F3) is a substituent, and R.sup.12, R.sup.13, R.sup.14 and R.sup.15 therein are hydrogen atoms. In one preferred aspect of the present invention, only R.sup.11 and R.sup.13 in the general formula (F3) are substituents, and R.sup.12, R.sup.14 and R.sup.15 therein are hydrogen atoms.

[0127] R.sup.1 to R.sup.7 in the general formula (F2) can include a group of the general formula (F3) where R.sup.11 to R.sup.15 are all hydrogen atoms (namely, a phenyl group). For example, R.sup.2, R.sup.4, and R.sup.6 can be phenyl groups.

[0128] In the general formula (F2), preferably, R.sup.8 and R.sup.9 are each independently one group selected from the group consisting of a hydrogen atom, a deuterium atom, a halogen atom, an alkyl group (for example, having 1 to 40 carbon atoms), an alkoxy group (for example, having 1 to 40 carbon atoms), an aryloxy group (for example, having 6 to 30 carbon atoms) and a cyano group, or a group formed by combining at least two such groups. In one preferred aspect of the present invention, R.sup.8 and R.sup.9 are the same. In one preferred aspect of the present invention, R.sup.8 and R.sup.9 are halogen atoms, especially preferably fluorine atoms.

[0129] In one aspect of the present invention, the number of the substituted or unsubstituted alkoxy group, the substituted or unsubstituted aryloxy group and the substituted or unsubstituted amino group existing in R.sup.1 to R.sup.9 in the general formula (F2) is preferably at least three in total, and a compound in which the total number is three can be employed, or a compound in which the total number is four can be employed. More preferably, the total number of the substituted or unsubstituted alkoxy group, the substituted or unsubstituted aryloxy group and the substituted or unsubstituted amino group existing in R.sup.1 to R.sup.7 in the general formula (F2) is preferably three or more in total, and for example, a compound in which the total number is three can be employed, or a compound in which the total number is four can be employed. In that case, an alkoxy group, an aryloxy group and an amino group may not exist in R.sup.8 and R.sup.9. Further preferably, the number of the substituted or unsubstituted alkoxy group, the substituted or unsubstituted aryloxy group and the substituted or unsubstituted amino group existing in R.sup.1, R.sup.3, R.sup.4, R.sup.5 and R.sup.7 in the general formula (F2) is preferably three or more in total, and for example, a compound in which the total number is three can be employed, or a compound in which the total number is four can be employed. In that case, an alkoxy group, an aryloxy group and an amino group may not exist in R.sup.2, R.sup.6, R.sup.8 and R.sup.9. In one preferred aspect of the present invention, the compound has at least three substituted or unsubstituted alkoxy groups. In one preferred aspect of the present invention, the compound has at least four substituted or unsubstituted alkoxy groups. In one preferred aspect of the present invention, the compound has at least one substituted or unsubstituted alkoxy group, and at least two substituted or unsubstituted aryloxy groups. In one preferred aspect of the present invention, the compound has at least two substituted or unsubstituted alkoxy groups, and at least one substituted or unsubstituted amino group. In one preferred aspect of the present invention, R.sup.1, R.sup.4 and R.sup.7 each have a substituted or unsubstituted alkoxy group or a substituted or unsubstituted aryloxy group. In one preferred aspect of the present invention, R.sup.1, R.sup.4 and R.sup.7 each have a substituted or unsubstituted alkoxy group.

[0130] In one aspect of the present invention, the number of the substituent having a Hammett's p value of less than 0.2 existing in R.sup.1 to R.sup.9 in the general formula (F2) is three or more in total. Examples of the substituent having a Hammett's p value of less than 0.2 include a methoxy group (0.27), an ethoxy group (0.24), an n-propoxy group (0.25), an isopropoxy group (0.45), and an n-butoxy group (0.32). On the other hand, a fluorine atom (0.06), a methyl group (0.17), an ethyl group (0.15), a tert-butyl group (0.20), an n-hexyl group (0.15), and a cyclohexyl group (0.15) are not substituents having a Hammett's p value of less than 0.2.

[0131] In one aspect of the present invention, a compound having three substituents each having a Hammett's p value of less than 0.2 in R.sup.1 to R.sup.9 in the general formula (F2) can be employed, or a compound having four such substituents can be employed. More preferably, the number of the substituents having a Hammett's p value of less than 0.2 in R.sup.1 to R.sup.7 in the general formula (F2) is three or more, and for example, a compound having three such substituents can be employed, or a compound having four such substituents can be employed. In that case, a substituent having a Hammett's p value of less than 0.2 may not exist in R.sup.8 and R.sup.9. Further preferably, the number of the substituents having a Hammett's p value of less than 0.2 in R.sup.1, R.sup.3, R.sup.4, R.sup.5 and R.sup.7 in the general formula (F2) is preferably three or more, and for example, a compound having three such substituents can be employed, or a compound having four such substituents can be employed. In that case, a substituent having a Hammett's p value of less than 0.2 may not exist in R.sup.2, R.sup.6, R.sup.8 and R.sup.9. In one preferred aspect of the present invention, R.sup.1, R.sup.4 and R.sup.7 each have a substituent having a Hammett's p value of less than 0.2.

[0132] In the present invention, a compound containing a carbazole structure can be selected for the light emitting material to be used in combination with an assist dopant. A compound not containing any of a carbazole structure, a dibenzofuran structure and a dibenzothiophene structure can be selected for the light emitting material to be used in combination with an assist dopant.

[0133] Preferred compounds for use as the light emitting material for use in combination with an assist dopant are shown below. However, the light emitting material usable in combination with an assist dopant in the present invention is not construed as limiting to the following specific examples. In the structural formulae of the following exemplary compounds, t-Bu represents a tertiary butyl group (tert-butyl group).

##STR00081## ##STR00082## ##STR00083## ##STR00084## ##STR00085## ##STR00086## ##STR00087## ##STR00088## ##STR00089## ##STR00090##

[0134] Derivatives of the above exemplary compounds include compounds thereof in which at least one hydrogen atom is substituted with a deuterium atom, an alkyl group, an aryl group, a heteroaryl group, or a diarylamino group.

[0135] In addition, compounds described in WO2015/022974, paragraphs 0220 to 0239 are also favorably employable as the light emitting material for use in combination with an assist dopant.

[0136] In one preferred aspect of the present invention, a compound represented by the following general formula (G) is used in the light emitting layer. Preferably, the compound represented by the general formula (G) is employed as the light emitting material for use in combination with an assist dopant. The compound represented by the general formula (G) can be employed also as an assist dopant.

##STR00091##

[0137] In the general formula (G), one of X.sup.1 and X.sup.2 is a nitrogen atom, and the other is a boron atom. In one aspect of the present invention, X.sup.1 is a nitrogen atom, and X.sup.2 is a boron atom. In that case, R.sup.17 and R.sup.18 bond to each other to form a single bond so as to form a pyrrole ring. In another aspect of the present invention, X.sup.1 is a boron atom, and X.sup.2 is a nitrogen atom. In that case, R.sup.21 and R.sup.22 bond to each other to form a single bond so as to form a pyrrole ring.

[0138] In the general formula (G), R.sup.1 to R.sup.26, A.sup.1, and A.sup.2 each independently represent a hydrogen atom, a deuterium atom, or a substituent.

[0139] R.sup.1 and R.sup.2, R.sup.2 and R.sup.3, R.sup.3 and R.sup.4, R.sup.4 and R.sup.5, R.sup.6 and R.sup.6, R.sup.6 and R.sup.7, R.sup.7 and R.sup.8, R.sup.8 and R.sup.9, R.sup.9 and R.sup.10, R.sup.10 and R.sup.11, R.sup.11 and R.sup.12, R.sup.13 and R.sup.14, R.sup.14 and R.sup.15, R.sup.15 and R.sup.16, R.sup.16 and R.sup.17, R.sup.17 and R.sup.18, R.sup.18 and R.sup.19, R.sup.19 and R.sup.20, R.sup.20 and R.sup.21, R.sup.21 and R.sup.22, R.sup.22 and R.sup.23, R.sup.23 and R.sup.24, R.sup.24 and R.sup.25, and R.sup.25 and R.sup.26 can bond to each other to form a cyclic structure.

[0140] The cyclic structure formed by bonding R.sup.7 and R.sup.8 to each other includes a boron atom and four carbon atoms as ring skeleton-constituting atoms. The cyclic structure formed by bonding R.sup.17 and R.sup.18 to each other includes a boron atom and four carbon atoms as ring skeleton-constituting atoms when X.sup.1 is a boron atom. When X.sup.1 is a nitrogen atom, the cyclic structure is limited to a pyrrole ring. The cyclic structure formed by bonding R.sup.21 and R.sup.22 to each other includes a boron atom and four carbon atoms as ring skeleton-constituting atoms when X.sup.2 is a boron atom. When X.sup.2 is a nitrogen atom, the cyclic structure is limited to a pyrrole ring. When R.sup.7 and R.sup.8, R.sup.17 and R.sup.18, and R.sup.21 and R.sup.22 bond to each other to form boron atom-containing cyclic structures, the cyclic structure is preferably a 5 to 7-membered ring, more preferably a 5 or 6-membered ring, further preferably a 6-membered ring. When R.sup.7 and R.sup.8, R.sup.17 and R.sup.18, and R.sup.21 and R.sup.22 bond to each other, these preferably form a single bond, O, S, N(R.sup.27), C(R.sup.28)(R.sup.29), Si(R.sup.30)(R.sup.31), B(R.sup.32), CO, or CS by bonding to each other, more preferably form O, S or N(R.sup.27), further preferably form N(R.sup.27). Here, each of R.sup.27 to R.sup.32 independently represents a hydrogen atom, a deuterium atom, or a substituent. As the substituent, a group selected from any of substituent groups A to E to be described below can be employed, but a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted heteroaryl group is preferable. In particular, R.sup.27 is preferably a substituted or unsubstituted aryl group. When R.sup.27 to R.sup.32 are substituents, R.sup.27 to R.sup.32 in the ring formed by bonding R.sup.7 and R.sup.8 to each other may further form a cyclic structure by bonding to at least one of R.sup.6 and R.sup.9, R.sup.27 to R.sup.32 in the ring formed by bonding R.sup.17 and R.sup.18 to each other may further form a cyclic structure by bonding to at least one of R.sup.16 and R.sup.19, and R.sup.27 to R.sup.32 in the ring formed by bonding R.sup.21 and R.sup.22 to each other may further form a cyclic structure by bonding to at least one of R.sup.20 and R.sup.23. In one aspect of the present invention, in only one combination among R.sup.7 and R.sup.8, R.sup.17 and R.sup.18, and R.sup.21 and R.sup.22, these bond to each other. In one aspect of the present invention, only two combinations of R.sup.7 and R.sup.8, R.sup.17 and R.sup.18, and R.sup.21 and R.sup.22 bond to each other. In one aspect of the present invention, all of R.sup.7 and R.sup.8, R.sup.17 and R.sup.18, and R.sup.21 and R.sup.22 bond to each other.

[0141] The cyclic structure formed by bonding R.sup.1 and R.sup.2, R.sup.2 and R.sup.3, R.sup.3 and R.sup.4, R.sup.4 and R.sup.5, R.sup.5 and R.sup.6, R.sup.6 and R.sup.7, R.sup.8 and R.sup.9, R.sup.9 and R.sup.10, R.sup.10 and R.sup.11, R.sup.11 and R.sup.12, R.sup.13 and R.sup.14, R.sup.14 and R.sup.15, R.sup.15 and R.sup.16, R.sup.16 and R.sup.17, R.sup.18 and R.sup.19, R.sup.19 and R.sup.20, R.sup.20 and R.sup.21, R.sup.22 and R.sup.23, R.sup.23 and R.sup.24, R.sup.24 and R.sup.25, and R.sup.25 and R.sup.26 to each other can be an aromatic ring or an aliphatic ring, or can contain a hetero atom, and further can be fused with at least one other ring. Here the hetero atom is preferably selected from the group consisting of a nitrogen atom, an oxygen atom and a sulfur atom. Examples of the cyclic structure to be formed include a benzene ring, a pyridine ring, a pyridazine ring, a pyrimidine ring, a pyrazine ring, a pyrrole ring, an imidazole ring, a pyrazole ring, a triazole ring, an imidazoline ring, a furan ring, a thiophene ring, an oxazole ring, an isoxazole ring, a thiazole ring, an isothiazole ring, a cyclohexadiene ring, a cyclohexene ring, a cyclopentene ring, a cycloheptatriene ring, a cycloheptadiene ring, a cycloheptene ring, and a ring in which one or more rings selected from the group consisting of these rings are further fused. In one preferred aspect of the present invention, the cyclic structure is a substituted or unsubstituted benzene ring (further, a ring can be fused), and is for example, a benzene ring which can be substituted with an alkyl group or an aryl group. In one preferred aspect of the present invention, the cyclic structure is a substituted or unsubstituted heteroaromatic ring, preferably a furan ring of benzofuran, or a thiophene ring of benzothiophene. Among R.sup.1 and R.sup.2, R.sup.2 and R.sup.3, R.sup.3 and R.sup.4, R.sup.4 and R.sup.5, R.sup.4 and R.sup.6, R.sup.6 and R.sup.7, R.sup.8 and R.sup.9, R.sup.9 and R.sup.10, R.sup.10 and R.sup.11, R.sup.11 and R.sup.12, R.sup.13 and R.sup.14, R.sup.14 and R.sup.15, R.sup.15 and R.sup.16, R.sup.16 and R.sup.17, R.sup.18 and R.sup.19, R.sup.19 and R.sup.20, R.sup.20 and R.sup.21, R.sup.22 and R.sup.23, R.sup.23 and R.sup.24, R.sup.24 and R.sup.25, and R.sup.25 and R.sup.26, the number of combinations that bond to each other to form cyclic structures can be 0, or can be, for example, any one of 1 to 6. For example, it can be any one of 1 to 4, 1 can be selected, 2 can be selected, or 3 or 4 can be selected. In one aspect of the present invention, in one combination selected from R.sup.1 and R.sup.2, R.sup.2 and R.sup.3, and R.sup.3 and R.sup.4, a cyclic structure is formed through bonding to each other. In one aspect of the present invention, R.sup.5 and R.sup.6 bond to each other to form a cyclic structure. In one aspect of the present invention, in one combination selected from R.sup.9 and R.sup.10, R.sup.10 and R.sup.11, and R.sup.11 and R.sup.12, a cyclic structure is formed through bonding to each other. In one aspect of the present invention, in both of R.sup.1 and R.sup.2, and R.sup.13 and R.sup.14, cyclic structures are formed through bonding to each other. In one aspect of the present invention, in one combination selected from R.sup.1 and R.sup.2, R.sup.2 and R.sup.3, and R.sup.3 and R.sup.4, a cyclic structure is formed through bonding to each other, and moreover R.sup.5 and R.sup.6 bond to each other to form a cyclic structure. In one aspect of the present invention, in both of R.sup.5 and R.sup.6, and R.sup.19 and R.sup.20, cyclic structures are formed through bonding to each other.

[0142] R.sup.1 to R.sup.26 which do not bond to adjacent Rn (n=1 to 26) are hydrogen atoms, deuterium atoms, or substituents. As the substituent, a group selected from any of substituent groups A to E to be described below can be employed.

[0143] Preferable substituents which R.sup.1 to R.sup.26 can have include a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, and a substituted or unsubstituted heteroaryl group. For example, the substituent can be a substituted or unsubstituted aryl group, and for example the substituent can be a substituted or unsubstituted alkyl group. As the substituent for the alkyl group, the aryl group, or the heteroaryl group mentioned herein, a group selected from any of substituent groups A to E can be employed, but the substituent is preferably at least one group selected from the group consisting of an alkyl group, an aryl group and a heteroaryl group, more preferably a group of Substituent Group E, and the groups can be unsubstituted. In one preferred aspect of the present invention, at least one of R.sup.1 to R.sup.6 is a substituent, preferably a group of Substituent Group E. For example, at least one of R.sup.2 to R.sup.6 is a substituent, preferably a group of Substituent Group E. For example, at least one of R.sup.5 and R.sup.6 is a substituent, preferably a group of Substituent Group E. In one preferred aspect of the present invention, at least one of R.sup.3 and R.sup.6 is a substituent, more preferably both are substituents, and a group of Substituent Group E is preferred. In one preferred aspect of the present invention, when X.sup.1 is a nitrogen atom, at least one of R.sup.15 and R.sup.20 is a substituent, more preferably both are substituents, and a group of Substituent Group E is preferred. Here, R.sup.17 and R.sup.18 bond to each other to form a single bond. In one preferred aspect of the present invention, when X.sup.2 is a nitrogen atom, at least one of R.sup.19 and R.sup.24 is a substituent, more preferably both are substituents, and a group of Substituent Group E is preferred. Here, R.sup.21 and R.sup.22 bond to each other to form a single bond. In one aspect of the present invention, at least one of R.sup.8 and R.sup.12 is a substituent, and preferably both are substituents. In one aspect of the present invention, R.sup.8, R.sup.10 and R.sup.12 are substituents. As for the substituent of R.sup.8 to R.sup.12, an unsubstituted alkyl group is preferable. In particular, the case where R.sup.8 and R.sup.12 are alkyl groups having 2 or more carbon atoms (preferably alkyl groups having 3 or more carbon atoms, more preferably alkyl groups having 3 to 8 carbon atoms, further preferably alkyl groups having 3 or 4 carbon atoms) is preferable because orientation becomes high when a film is formed. Among them, particularly preferred is a case where R.sup.8 and R.sup.12 are substituents (preferably alkyl groups, more preferably alkyl groups having 2 or more carbon atoms, further preferably alkyl groups having 3 or more carbon atoms, still further preferably alkyl groups having 3 to 8 carbon atoms, particularly preferably alkyl groups having 3 or 4 carbon atoms), and moreover, at least one of R.sup.1 to R.sup.6 is a substituent (preferably a group of Substituent Group E). When X.sup.1 is a boron atom, at least one of R.sup.13 and R.sup.17 is a substituent, and preferably both are substituents. In one aspect of the present invention, when X.sup.1 is a boron atom, R.sup.13, R.sup.15 and R.sup.17 are substituents. When X.sup.1 is a boron atom, as for the substituent of R.sup.13 to R.sup.17, an unsubstituted alkyl group is preferable. When X.sup.2 is a boron atom, at least one of R.sup.22 and R.sup.26 is a substituent, and preferably both are substituents. In one aspect of the present invention, when X.sup.2 is a boron atom, R.sup.22, R.sup.24 and R.sup.26 are substituents. When X.sup.2 is a boron atom, as for the substituent of R.sup.22 to R.sup.26, an unsubstituted alkyl group is preferable. Specific examples of the group that bonds to the boron atom represented by B in the general formula (G) or the boron atom represented by X.sup.1 or X.sup.2 will be given below. Meanwhile, groups bonded to the boron atom, which can be adopted in the present invention, are not construed as limiting to the following specific examples. In the present description, indication of CH.sub.3 is omitted for a methyl group. * indicates a bonding site.

##STR00092## ##STR00093##

[0144] Hereinafter, specific examples of R.sup.1 to R.sup.26 in the general formula (G) will be given. G1 to G9 are preferable as R.sup.1 to R.sup.7, as R.sup.13 to R.sup.21 when X.sup.1 is a nitrogen atom, and as R.sup.18 to R.sup.26 when X.sup.2 is a nitrogen atom, G1 to G7 are preferable as R.sup.8 to R.sup.12, as R.sup.22 to R.sup.26 when X.sup.1 is a nitrogen atom, and as R.sup.13 to R.sup.17 when X.sup.2 is a nitrogen atom. Meanwhile, groups bonded to the boron atom, which can be adopted in the present invention, are not construed as limiting to the following specific examples. D represents a deuterium atom. * indicates a bonding site.

##STR00094##

[0145] A.sup.1 and A.sup.2 are hydrogen atoms, deuterium atoms, or substituents. As the substituent, a group selected from any of substituent groups A to E to be described below can be employed.

[0146] In one preferred aspect of the present invention, each of A.sup.1 and A.sup.2 is independently a hydrogen atom or a deuterium atom. For example, A.sup.1 and A.sup.2 are hydrogen atoms. For example, A.sup.1 and A.sup.2 are deuterium atoms. [0147] One of A.sup.1 and A.sup.2 can be a substituent. Further, each of A.sup.1 and A.sup.2 can be independently a substituent. A preferable substituent which A.sup.1 and A.sup.2 can have is an acceptor group. The acceptor group is a group having a positive Hammett's p value.

[0148] The acceptor group which A.sup.1 and A.sup.2 can have is more preferably a group having a Hammett's p value greater than 0.2. Examples of the group having a Hammett's op value greater than 0.2 include a cyano group, an aryl group substituted with at least a cyano group, a fluorine atom-containing group, and a substituted or unsubstituted heteroaryl group containing a nitrogen atom as a ring skeleton-constituting atom. The aryl group substituted with at least a cyano group, which is mentioned herein, can be substituted with a substituent other than the cyano group (for example, an alkyl group or an aryl group), but can be an aryl group substituted with only a cyano group. The aryl group substituted with at least a cyano group is preferably a phenyl group substituted with at least a cyano group. The number of substitutions of the cyano group is preferably one or two, and, for example, can be one, or can be two. As the fluorine atom-containing group, a fluorine atom, a fluoroalkyl group, and an aryl group substituted with at least a fluorine atom or a fluoroalkyl group can be mentioned. The fluoroalkyl group is preferably a perfluoroalkyl group, and the number of carbon atoms thereof is preferably 1 to 6, more preferably 1 to 3. Further, the heteroaryl group containing a nitrogen atom as a ring skeleton-constituting atom can be a monocycle, or can be a fused ring in which two or more rings are fused. In the case of a fused ring, the number of rings after fusing is preferably two to six, and, for example, can be selected from two to four, or can be two. Specific examples of the ring constituting the heteroaryl group include a pyridine ring, a pyrimidine ring, a pyrazine ring, a triazine ring, a quinoline ring, an isoquinoline ring, a quinazoline ring, a quinoxaline ring, and a naphthyridine ring other than the quinazoline ring or the quinoxaline ring. The ring constituting the heteroaryl group can be substituted with a deuterium atom or a substituent, and as for the substituent, for example, one group selected from the group consisting of an alkyl group, an aryl group and a heteroaryl group or a group formed by combining two or more thereof can be mentioned. As the acceptor group that A.sup.1 and A.sup.2 can have, a cyano group is particularly preferable.

[0149] In one aspect of the present invention, at least one of A.sup.1 and A.sup.2 is an acceptor group. In one aspect of the present invention, only one of A.sup.1 and A.sup.2 is an acceptor group. In one aspect of the present invention, both A.sup.1 and A.sup.2 are the same acceptor groups. In one aspect of the present invention, A.sup.1 and A.sup.2 are different acceptor groups. In one aspect of the present invention, A.sup.1 and A.sup.2 are cyano groups. In one aspect of the present invention, A.sup.1 and A.sup.2 are halogen atoms, for example, bromine atoms.

[0150] Hereinafter, specific examples of the acceptor group that can be adopted in the present invention will be illustrated. However, the acceptor group that can be used in the present invention is not construed as limiting to the following specific examples. In the present description, indication of CH.sub.3 is omitted for a methyl group. Thus, for example, A15 indicates a group including two 4-methylphenyl groups. Further, D represents a deuterium atom. * indicates a bonding site.

##STR00095## ##STR00096## ##STR00097## ##STR00098## ##STR00099## ##STR00100## ##STR00101##

[0151] When X.sup.1 is a nitrogen atom, R.sup.7 and R.sup.8 bond via a nitrogen atom to form a 6-membered ring, R.sup.21 and R.sup.22 bond via a nitrogen atom to form a 6-membered ring, and R.sup.17 and R.sup.18 bond to each other to form a single bond, at least one of R.sup.1 to R.sup.6 is a substituted or unsubstituted aryl group, or any of R.sup.1 and R.sup.2, R.sup.2 and R.sup.3, R.sup.3 and R.sup.4, R.sup.4 and R.sup.5, and R.sup.5 and R.sup.6 bond to each other to form an aromatic ring (a substituted or unsubstituted benzene ring which can be fused) or a heteroaromatic ring (preferably a substituted or unsubstituted furan ring of benzofuran which can be fused, or a substituted or unsubstituted thiophene ring of benzothiophene which can be fused).

[0152] Further, when X.sup.1 is a boron atom, X.sup.2 is a nitrogen atom, and R.sup.7 and R.sup.8, and R.sup.17 and R.sup.18 bond to each other to form boron atom-containing cyclic structures, the cyclic structure is a 5 to 7-membered ring, and in the case of a 6-membered ring, R.sup.7 and R.sup.8, and R.sup.17 and R.sup.18 bond to each other to form B(R.sup.32), CO, CS or N(R.sup.27). R.sup.27 preferably represents a hydrogen atom, a deuterium atom, or a substituent.

[0153] When X.sup.1 in the general formula (G) is a nitrogen atom, the compound of the present invention has the following skeleton (1a). When X.sup.2 in the general formula (G) is a nitrogen atom, the compound of the present invention has the following skeleton (1b).

##STR00102##

[0154] In the skeletons (1a) and (1b), each hydrogen atom can be substituted with a deuterium atom or a substituent. Further, it can be substituted with a linking group together with an adjacent hydrogen atom to form a cyclic structure. For details, corresponding descriptions on R.sup.1 to R.sup.26, A.sup.1, and A.sup.2 in the general formula (G) can be referred to. Compounds, in which all phenyl groups bonding to boron atoms in the skeletons (1a) and (1b) are substituted with mesityl groups, 2,6-diisopropylphenyl groups or 2,4,6-triisopropylphenyl groups, can be exemplified. In one aspect of the present invention, each hydrogen atom in the skeletons (1a) and (1b) is not substituted with a linking group together with an adjacent hydrogen atom to form a cyclic structure.

[0155] As one preferable group of compounds having the skeleton (1a), compounds represented by the following general formula (1a) can be exemplified.

##STR00103##

[0156] In the general formula (1a), Ar.sup.1 to Ar.sup.4 each independently represent a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and, for example, a substituted or unsubstituted aryl group can be preferably selected. R.sup.41 and R.sup.42 each independently represent a substituted or unsubstituted alkyl group. m1 and m2 each independently represent an integer of 0 to 5, n1 and n3 each independently represent an integer of 0 to 4, and n2 and n4 each independently represent an integer of 0 to 3. Each of A.sup.1 and A.sup.2 independently represents a hydrogen atom, a deuterium atom, or a substituent. It is preferable that at least one of n1 to n4 is 1 or more, and each of m1 and m2 is independently any integer of 1 to 5.

[0157] In one aspect of the present invention, n1 to n4 each independently represent an integer of 0 to 2. In one preferred aspect of the present invention, at least one of n1 to n4 is 1 or more. Preferably, at least one of n1 and n2 is 1 or more, and at least one of n3 and n4 is 1 or more. In one aspect of the present invention, each of n1 and n3 is independently 1 or 2, and n2 and n4 are 0. In one aspect of the present invention, each of n2 and n4 is independently 1 or 2, and n1 and n3 are 0. In one aspect of the present invention, each of n1 to n4 is independently 1 or 2. In one aspect of the present invention, n1 and n3 are the same, and n2 and n4 are the same. In one aspect of the present invention, n1 and n3 are 1, and n2 and n4 are 0. In one aspect of the present invention, n1 and n3 are 0, and n2 and n4 are 1. In one aspect of the present invention, n1 to n4 are all 1. The bonding sites of Ar.sup.1 to Ar.sup.4 can be at least one of 3 and 6 positions in the carbazole ring, can be at least one of 2 and 7 positions, can be at least one of 1 and 8 positions, or can be at least one of 4 and 5 positions. The bonding sites of Ar.sup.1 to Ar.sup.4 can be both of 3 and 6 positions in the carbazole ring, can be both of 2 and 7 positions, can be both of 1 and 8 positions, or can be both of 4 and 5 positions. For example, at least one of 3 and 6 positions can be preferably selected, or both of 3 and 6 positions can be further preferably selected. In one preferred aspect of the present invention, Ar.sup.1 to Ar.sup.4 are all the same groups. In one preferred aspect of the present invention, each of Ar.sup.1 to Ar.sup.4 is independently a substituted or unsubstituted aryl group, more preferably a substituted or unsubstituted phenyl group or naphthyl group, further preferably a substituted or unsubstituted phenyl group. As the substituent, a group selected from any of Substituent Groups A to E to be described below can be mentioned, but an unsubstituted phenyl group is also preferable. Specific preferable examples of Ar.sup.1 to Ar.sup.4 include a phenyl group, an o-biphenyl group, a m-biphenyl group, a p-biphenyl group, and a terphenyl group.

[0158] In one aspect of the present invention, each of m1 and m2 is independently 0. In one aspect of the present invention, each of m1 and m2 is independently any integer of 1 to 5. In one aspect of the present invention, m1 and m2 are the same. In one aspect of the present invention, R.sup.41 and R.sup.42 are alkyl groups having 1 to 6 carbon atoms and can be selected from, for example, alkyl groups having 1 to 3 carbon atoms, or a methyl group can be selected. When a carbon atom bonded to a boron atom is the 1-position, as the substitution position of the alkyl group, only the 2-position, only the 3-position, only the 4-position, the 3 and 5 positions, the 2 and 4 positions, the 2 and 6 positions, the 2, 4, and 6 positions, and the like can be exemplified. At least the 2-position is preferable, and at least 2 and 6 positions are more preferable.

[0159] For descriptions and preferable ranges of A.sup.1 and A.sup.2, corresponding descriptions on the general formula (G) can be referred to.

[0160] Hereinafter, specific examples of the compound represented by the general formula (1a) will be given. Compounds of the general formula (1a) which can be used in the present invention are not construed as limiting to specific examples in the following group. For example, as one preferable group, a group including all the following compounds, except for the compound at the center in the fourth row and the compound at the center in the eighth row, can be mentioned.

##STR00104## ##STR00105## ##STR00106## ##STR00107## ##STR00108## ##STR00109## ##STR00110## ##STR00111## ##STR00112## ##STR00113## ##STR00114## ##STR00115## ##STR00116## ##STR00117## ##STR00118## ##STR00119## ##STR00120## ##STR00121## ##STR00122## ##STR00123## ##STR00124## ##STR00125## ##STR00126## ##STR00127##

##STR00128## ##STR00129##

[0161] Hereinafter, another group of specific examples of the compound represented by the general formula (1a) will be given. Compounds of the general formula (1a) that can be used in the present invention are not construed as limiting to specific examples in the following group.

##STR00130## ##STR00131## ##STR00132## ##STR00133## ##STR00134## ##STR00135## ##STR00136## ##STR00137## ##STR00138## ##STR00139## ##STR00140## ##STR00141## ##STR00142## ##STR00143## ##STR00144## ##STR00145## ##STR00146## ##STR00147## ##STR00148## ##STR00149## ##STR00150##

[0162] As one preferable group of compounds having the skeleton (1b), compounds represented by the following general formula (1b) can be exemplified.

##STR00151##

[0163] In the general formula (1b), each of Ar.sup.5 to Ar.sup.8 independently represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and, for example, a substituted or unsubstituted aryl group can be preferably selected. Each of R.sup.43 and R.sup.44 independently represents a substituted or unsubstituted alkyl group. Each of m3 and m4 independently represents an integer of 0 to 5, each of n6 and n8 independently represents an integer of 0 to 3, and each of n5 and n7 independently represents an integer of 0 to 4. Each of A.sup.1 and A.sup.2 independently represents a hydrogen atom, a deuterium atom, or a substituent. In relation to details of Ar.sup.5 to Ar.sup.8, R.sup.43 and R.sup.44, m3 and m4, n5 to n8, A.sup.1, and A.sup.2, the descriptions on Ar.sup.1 to Ar.sup.4, R.sup.41 and R.sup.42, m1 and m2, n1 to n4, A.sup.1, and A.sup.2 in the general formula (1a) can be referred to. It is preferable that at least one of n5 to n8 is 1 or more, and each of m3 and m4 is independently any integer of 1 to 5.

[0164] Hereinafter, specific examples of the compound represented by the general formula (1b) will be given. Compounds of the general formula (1b) that can be used in the present invention are not construed as limiting to the following specific examples.

##STR00152## ##STR00153## ##STR00154## ##STR00155##

[0165] When R.sup.7 and R.sup.8 in the general formula (G) bond to each other to form N-Ph, the compound of the present invention has, for example, the following skeleton (2a) where X.sup.1 is a nitrogen atom, and, has for example, the following skeleton (2b) where X.sup.2 is a nitrogen atom. Ph is a phenyl group.

##STR00156##

[0166] In the skeletons (2a) and (2b), each hydrogen atom can be substituted with a deuterium atom or a substituent. Further, it can be substituted with a linking group together with an adjacent hydrogen atom to form a cyclic structure. For details, corresponding descriptions on R.sup.1 to R.sup.26, A.sup.1, and A.sup.2 in the general formula (G) can be referred to. At least one hydrogen atom of a benzene ring forming a carbazole partial structure included in the skeleton (2a) is substituted with a substituted or unsubstituted aryl group. In one aspect of the present invention, each hydrogen atom in the skeletons (2a) and (2b) is not substituted with a linking group together with an adjacent hydrogen atom to form a cyclic structure.

[0167] As one preferable group of compounds having the skeleton (2a), compounds represented by the following general formula (2a) can be exemplified.

##STR00157##

[0168] In the general formula (2a), each of Ar.sup.9 to Ar.sup.14 independently represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and for example, a substituted or unsubstituted aryl group can be preferably selected. Each of n9, n11, n12, and n14 independently represents an integer of 0 to 4, and each of n10 and n13 independently represents an integer of 0 to 2. Meanwhile, at least one of n9, n10, n12, and n13 is 1 or more. Each of A.sup.1 and A.sup.2 independently represents a hydrogen atom, a deuterium atom, or a substituent.

[0169] In one aspect of the present invention, n9 to n14 each independently represent an integer of 0 to 2. In one aspect of the present invention, at least one of n9 to n14 is 1 or more, and for example, n9 and n12 can be 1 or more or n10 and n13 can be 1 or more. In one preferred aspect of the present invention, at least one of n9, n10, n12, and n13 is 1 or more. In one aspect of the present invention, each of n9 and n12 is independently 1 or 2, and n10, n11, n13, and n14 are 0. In one aspect of the present invention, each of n10 and n13 is independently 1 or 2, and n9, n11, n12, and n14 are 0. In one aspect of the present invention, each of n9 and n12 is independently 1 or 2, each of n10 and n13 is independently 1 or 2, and n1 and n14 are 0. In one aspect of the present invention, n9 to n14 are all 1. The bonding sites of A.sup.9 to Ar.sup.14 can be 3 and 6 positions of a carbazole ring, or can be other positions. In one preferred aspect of the present invention, Ar.sup.9 to Ar.sup.14 are all the same group. For preferable groups for Ar.sup.9 to Ar.sup.14, corresponding descriptions on Ar.sup.1 to A.sup.4 can be referred to. For descriptions and preferable ranges of A.sup.1 and A.sup.2, corresponding descriptions on the general formula (G) can be referred to.

[0170] Hereinafter, specific examples of the compound represented by the general formula (2a) will be given. Compounds of the general formula (2a) that can be used in the present invention are not construed as limiting to the following specific examples.

##STR00158## ##STR00159##

[0171] As one preferable group of compounds having the skeleton (2b), compounds represented by the following general formula (2b) can be exemplified.

##STR00160##

[0172] In the general formula (2b), each of Ar.sup.15 to Ar.sup.20 independently represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and, for example, a substituted or unsubstituted aryl group can be preferably selected. Each of n15, n17, n18, and n20 independently represents an integer of 0 to 4, and each of n16 and n19 independently represents an integer of 0 to 2. Each of A.sup.1 and A.sup.2 independently represents a hydrogen atom, a deuterium atom, or a substituent. For details of Ar.sup.15 to Ar.sup.20, n15 to n20, A.sup.1, and A.sup.2, descriptions on Ar.sup.9 to Ar.sup.14, n9 to n14, A.sup.1, and A.sup.2 in the general formula (2a) can be referred to in this order.

[0173] Hereinafter, specific examples of the compound represented by the general formula (2b) will be given. Compounds of the general formula (2b) that can be used in the present invention are not construed as limiting to the following specific examples.

##STR00161## ##STR00162##

[0174] When R.sup.7 and R.sup.8 in the general formula (G) bond to each other to form a single bond, the compound of the present invention has, for example, the following skeleton (3a) if X.sup.1 is a nitrogen atom, and has, for example, the following skeleton (3b) if X.sup.2 is a nitrogen atom.

##STR00163##

[0175] In the skeletons (3a) and (3b), each hydrogen atom can be substituted with a deuterium atom or a substituent. Further, it can be substituted with a linking group together with an adjacent hydrogen atom to form a cyclic structure. For details, corresponding descriptions on R.sup.1 to R.sup.26, A.sup.1, and A.sup.2 in the general formula (G) can be referred to. In one aspect of the present invention, each hydrogen atom in the skeletons (3a) and (3b) is not substituted with a linking group together with an adjacent hydrogen atom to form a cyclic structure.

[0176] As one preferable group of compounds having the skeleton (3a), compounds represented by the following general formula (3a) can be exemplified.

##STR00164##

[0177] In the general formula (3a), each of Ar.sup.21 to Ar.sup.26 independently represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and for example, a substituted or unsubstituted aryl group can be preferably selected. Each of n21, n23, n24, and n26 independently represents an integer of 0 to 4, and each of n22 and n25 independently represents an integer of 0 to 2. Each of A.sup.1 and A.sup.2 independently represents a hydrogen atom, a deuterium atom, or a substituent. For details of Ar.sup.21 to Ar.sup.25, and n21 to n25, descriptions on Ar.sup.9 to Ar.sup.14, n9 to n14, A.sup.1, and A.sup.2 in the general formula (2a) can be referred to.

[0178] Hereinafter, specific examples of the compound represented by the general formula (3a) will be given. Compounds of the general formula (3a) that can be used in the present invention are not construed as limiting to the following specific examples.

##STR00165## ##STR00166##

[0179] As one preferable group of compounds having the skeleton (3b), compounds represented by the following general formula (3b) can be exemplified.

##STR00167##

[0180] In the general formula (3b), each of Ar.sup.27 to Ar.sup.32 independently represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and for example, a substituted or unsubstituted aryl group can be preferably selected. Each of n27, n29, n30, and n32 independently represents an integer of 0 to 4, and each of n28 and n31 independently represents an integer of 0 to 2. Each of A.sup.1 and A.sup.2 independently represents a hydrogen atom, a deuterium atom, or a substituent. For details of Ar.sup.27 to Ar.sup.32, n27 to n32, A.sup.1, and A.sup.2, descriptions on Ar.sup.15 to Ar.sup.20, n15 to n20, A.sup.1, and A.sup.2 in the general formula (2b) can be referred to in this order.

[0181] Hereinafter, specific examples of the compound represented by the general formula (3b) will be given. Compounds of the general formula (3b) that can be used in the present invention are not construed as limiting to the following specific examples.

##STR00168## ##STR00169## ##STR00170## ##STR00171##

[0182] In one preferred aspect of the present invention, compounds in which another ring is fused with two benzene rings forming a carbazole partial structure existing in the general formula (G) are selected. Among them, a compound in which a benzofuran ring is fused, a compound in which a benzothiophene ring is fused, and a compound in which a benzene ring is fused can be particularly preferably selected. Hereinafter, compounds in which these rings are fused will be described with reference to specific examples.

[0183] A compound in which a benzofuran ring or a benzothiophene ring is fused with a benzene ring to which a boron atom does not directly bond, between two benzene rings forming a carbazole partial structure existing in the general formula (G), can be preferably mentioned. Examples of such a compound include a compound having the following skeleton (4a), and a compound having the following skeleton (4b).

##STR00172##

[0184] In the skeletons (4a) and (4b), each of Y.sup.1 to Y.sup.4 independently represents two hydrogen atoms, a single bond or N(R.sup.27). Two hydrogen atoms mentioned herein indicate a state where two benzene rings bonding to a boron atom are not linked to each other. It is preferable that Y.sup.1 and Y.sup.2 are the same, and Y.sup.3 and Y.sup.4 are the same, but they can be different from each other. In one aspect of the present invention, Y.sup.1 to Y.sup.4 are single bonds. In one aspect of the present invention, Y.sup.1 to Y.sup.4 are N(R.sup.27). R.sup.27 represents a hydrogen atom, a deuterium atom, or a substituent.

[0185] Each of Z.sup.1 to Z.sup.4 independently represents an oxygen atom or a sulfur atom. It is preferable that Z.sup.1 and Z.sup.2 are the same, and Z.sup.3 and Z.sup.4 are the same, but they can be different from each other. In one aspect of the present invention, Z.sup.1 to Z.sup.4 are oxygen atoms. Here, a furan ring of benzofuran is fused with the benzene ring constituting the carbazole partial structure in (4a) and (4b). The orientation of the fused furan ring is not limited. In one aspect of the present invention, Z.sup.1 to Z.sup.4 are sulfur atoms. Here, a thiophene ring of benzothiophene is fused with the benzene ring constituting the carbazole partial structure in (4a) and (4b). The orientation of the fused thiophene ring is not limited.

[0186] Each hydrogen atom in the skeletons (4a) and (4b) can be substituted with a deuterium atom or a substituent. Further, it can be substituted with a linking group together with an adjacent hydrogen atom to form a cyclic structure. For details, corresponding descriptions on R.sup.1 to R.sup.26, A.sup.1, and A.sup.2 in the general formula (G) can be referred to. In one aspect of the present invention, each hydrogen atom in the skeletons (4a) and (4b) is not substituted with a linking group together with an adjacent hydrogen atom to form a cyclic structure.

[0187] As one preferable group of compounds having the skeleton (4a), compounds represented by the following general formula (4a) can be exemplified. It is assumed that X in specific examples is an oxygen atom or a sulfur atom, and a compound in which X is an oxygen atom and a compound in which X is a sulfur atom are disclosed, respectively. Further, in specific examples of compounds represented by other subsequent general formulas, X has the same meaning.

##STR00173##

[0188] In the general formula (4a), each of Ar.sup.51 and Ar.sup.52 independently represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and for example, a substituted or unsubstituted aryl group can be preferably selected. Each of R.sup.51 and R.sup.52 independently represents a substituted or unsubstituted alkyl group. Each of m51 and m52 independently represents an integer of 0 to 4. Each of n51 and n52 independently represents an integer of 0 to 2. Each of Y.sup.1 to Y.sup.4 independently represents two hydrogen atoms, a single bond or N(R.sup.27). R.sup.27 represents a hydrogen atom, a deuterium atom, or a substituent. Each of Z.sup.1 to Z.sup.4 independently represents an oxygen atom or a sulfur atom. Each of A.sup.1 and A.sup.2 independently represents a hydrogen atom, a deuterium atom, or a substituent.

[0189] In one aspect of the present invention, n51 and n52 are the same number. For example, n51 and n52 can be 0, and n5l and n52 can be 1. In one aspect of the present invention, m5l and m52 are the same number. In one aspect of the present invention, m5l and m52 are integers of 0 to 3. For example, m51 and m52 can be 0, m51 and m52 can be 1, m51 and m52 can be 2, and m51 and m52 can be 3. In relation to preferable groups for Ar.sup.51, Ar.sup.52, R.sup.51, R.sup.52, A.sup.1, and A.sup.2, corresponding descriptions on Ar.sup.1 to Ar.sup.4, R.sup.41 to R.sup.42, A.sup.1, and A.sup.2 in the general formula (1a) can be referred to.

[0190] Hereinafter, specific examples of the compound represented by the general formula (4a) will be given. Compounds of the general formula (4a) that can be used in the present invention are not construed as limiting to specific examples in the following one group. In relation to specific examples including X, it is assumed that a compound in which all X's in the molecule are oxygen atoms, and a compound in which all X's in the molecule are sulfur atoms are disclosed, respectively. A compound in which some of X's in the molecule are oxygen atoms, and the rest are sulfur atoms may also be adopted.

##STR00174## ##STR00175## ##STR00176## ##STR00177## ##STR00178## ##STR00179## ##STR00180## ##STR00181## ##STR00182## ##STR00183## ##STR00184## ##STR00185## ##STR00186## ##STR00187## ##STR00188## ##STR00189## ##STR00190## ##STR00191## ##STR00192## ##STR00193##

[0191] Hereinafter, another group of specific examples of the compound represented by the general formula (4a) will be given. Compounds of the general formula (4a) that can be used in the present invention are not construed as limiting to specific examples in the following one group.

##STR00194## ##STR00195## ##STR00196## ##STR00197## ##STR00198## ##STR00199## ##STR00200##

[0192] As one preferable group of compounds having the skeleton (4b), compounds represented by the following general formula (4b) can be exemplified.

##STR00201##

[0193] In the general formula (4b), each of Ar.sup.53 and Ar.sup.54 independently represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and for example, a substituted or unsubstituted aryl group can be preferably selected. Each of R.sup.53 and R.sup.54 independently represents a substituted or unsubstituted alkyl group. Each of m53 and m54 independently represents an integer of 0 to 4. Each of n53 and n54 independently represents an integer of 0 to 2. Each of Y.sup.3 and Y.sup.4 independently represents two hydrogen atoms, a single bond or N(R.sup.27). R.sup.27 represents a hydrogen atom, a deuterium atom, or a substituent. Each of Z.sup.3 and Z.sup.4 independently represents an oxygen atom or a sulfur atom. Each of A.sup.1 and A.sup.2 independently represents a hydrogen atom, a deuterium atom, or a substituent. In relation to details of Ar.sup.53, Ar.sup.54, R.sup.53, R.sup.54, m53, m54, n53, n54, A.sup.1, and A.sup.2, the descriptions on Ar.sup.51, Ar.sup.52, R.sup.51, R.sup.52, m51, m52, n51, n52, A.sup.1, and A.sup.2 in the general formula (4a) can be referred to.

[0194] Hereinafter, specific examples of the compound represented by the general formula (4b) will be given. Compounds of the general formula (4b) that can be used in the present invention are not construed as limiting to the following specific examples. In relation to specific examples including X, it is assumed that a compound in which all X's in the molecule are oxygen atoms, and a compound in which all X's in the molecule are sulfur atoms are disclosed, respectively. A compound in which some of X's in the molecule are oxygen atoms, and the rest are sulfur atoms may also be adopted.

##STR00202## ##STR00203## ##STR00204##

[0195] A compound in which a benzofuran ring or a benzothiophene ring is fused with a benzene ring to which a boron atom directly bonds, between two benzene rings forming a carbazole partial structure existing in the general formula (G), can be preferably mentioned. Examples of such a compound include a compound having the following skeleton (5a) and a compound having the following skeleton (5b).

##STR00205##

[0196] In the skeletons (5a) and (5b), each of Y.sup.5 to Y.sup.8 independently represents two hydrogen atoms, a single bond or N(R.sup.27). Each of Z.sup.5 to Z.sup.8 independently represents an oxygen atom or a sulfur atom. In relation to details of Y.sup.5 to Y.sup.8, and Z.sup.5 to Z.sup.8, corresponding descriptions for the skeletons (4a) and (4b) can be referred to. In one aspect of the present invention, each hydrogen atom in the skeletons (5a) and (5b) is not substituted with a linking group together with an adjacent hydrogen atom to form a cyclic structure.

[0197] As one preferable group of compounds having the skeleton (5a), compounds represented by the following general formula (5a) can be exemplified.

##STR00206##

[0198] In the general formula (5a), each of Ar.sup.55 and Ar.sup.56 independently represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and for example, a substituted or unsubstituted aryl group can be preferably selected. Each of R.sup.55 and R.sup.56 independently represents a substituted or unsubstituted alkyl group. Each of m55 and m56 independently represents an integer of 0 to 4. Each of n55 and n56 independently represents an integer of 0 to 4. Each of Y.sup.5 and Y.sup.6 independently represents two hydrogen atoms, a single bond or N(R.sup.27). R.sup.27 represents a hydrogen atom, a deuterium atom, or a substituent. Each of Z.sup.5 and Z.sup.6 independently represents an oxygen atom or a sulfur atom. Each of A.sup.1 and A.sup.2 independently represents a hydrogen atom, a deuterium atom, or a substituent.

[0199] In one aspect of the present invention, n55 and n56 are integers of 0 to 2. For example, n55 and n56 can be 0, and n55 and n56 can be 1. In one aspect of the present invention, m51 and m52 are the same number. In relation to details of m55 and m56, descriptions on m51 and m52 in the general formula (4a) can be referred to. In relation to preferable groups for Ar.sup.55, Ar.sup.56, R.sup.55, R.sup.56, A.sup.1, and A.sup.2, corresponding descriptions on Ar.sup.1, Ar.sup.3, R.sup.41, R.sup.42, A.sup.1, and A.sup.2 in the general formula (1a) can be referred to.

[0200] Hereinafter, specific examples of the compound represented by the general formula (5a) will be given. Compounds of the general formula (5a) that can be used in the present invention are not construed as limiting to specific examples in the following one group. In relation to specific examples including X, it is assumed that a compound in which all X's in the molecule are oxygen atoms, and a compound in which all X's in the molecule are sulfur atoms are disclosed, respectively. A compound in which some of X's in the molecule are oxygen atoms, and the rest are sulfur atoms may also be adopted.

##STR00207## ##STR00208## ##STR00209## ##STR00210## ##STR00211## ##STR00212## ##STR00213## ##STR00214## ##STR00215## ##STR00216##

[0201] Hereinafter, another group of specific examples of the compound represented by the general formula (5a) will be given. Compounds of the general formula (5a) that can be used in the present invention are not construed as limiting to specific examples in the following one group.

##STR00217##

[0202] As one preferable group of compounds having the skeleton (5b), compounds represented by the following general formula (5b) can be exemplified.

##STR00218##

[0203] In the general formula (5b), each of Ar.sup.57 and Ar.sup.58 independently represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and for example, a substituted or unsubstituted aryl group can be preferably selected. Each of R.sup.57 and R.sup.58 independently represents a substituted or unsubstituted alkyl group. Each of m57 and m58 independently represents an integer of 0 to 4. Each of n57 and n58 independently represents an integer of 0 to 4. Each of Y.sup.7 and Y.sup.8 independently represents two hydrogen atoms, a single bond or N(R.sup.27). R.sup.27 represents a hydrogen atom, a deuterium atom, or a substituent. Each of Z.sup.7 and Z.sup.8 independently represents an oxygen atom or a sulfur atom. Each of A.sup.1 and A.sup.2 independently represents a hydrogen atom, a deuterium atom, or a substituent. In relation to details of Ar.sup.57, Ar.sup.58, R.sup.57, R.sup.58, m57, m58, n57, n58, A.sup.1, and A.sup.2, descriptions on Ar.sup.55, Ar.sup.56, R.sup.55, R.sup.56, m55, m56, n55, n56, A.sup.1, and A.sup.2 in the general formula (5a) can be referred to.

[0204] Hereinafter, specific examples of the compound represented by the general formula (5b) will be given. Compounds of the general formula (5b) that can be used in the present invention are not construed as limiting to specific examples in the following one group. In relation to specific examples including X, it is assumed that a compound in which all X's in the molecule are oxygen atoms, and a compound in which all X's in the molecule are sulfur atoms are disclosed, respectively. A compound in which some of X's in the molecule are oxygen atoms, and the rest are sulfur atoms may also be adopted.

##STR00219## ##STR00220##

[0205] Hereinafter, another group of specific examples of the compound represented by the general formula (5b) will be given. Compounds of the general formula (5b) that can be used in the present invention are not construed as limiting to specific examples in the following one group.

##STR00221## ##STR00222## ##STR00223##

[0206] A compound in which benzofuran rings or benzothiophene rings are fused with both of two benzene rings forming a carbazole partial structure existing in the general formula (G) can be preferably mentioned. Examples of such a compound include a compound having the following skeleton (6a), and a compound having the following skeleton (6b).

##STR00224##

[0207] In the skeletons (6a) and (6b), each of Y.sup.9 to Y.sup.12 independently represents two hydrogen atoms, a single bond or N(R.sup.27). Each of Z.sup.9 to Z.sup.16 independently represents an oxygen atom or a sulfur atom. It is preferable that Z.sup.9 to Z.sup.16 are the same, but they can be different. In one aspect of the present invention, Z.sup.9 to Z.sup.16 are oxygen atoms. In one aspect of the present invention, Z.sup.9 to Z.sup.16 are sulfur atoms. In relation to details of Y.sup.9 to Y.sup.12, corresponding descriptions for the skeletons (4a) and (4b) can be referred to. In one aspect of the present invention, each hydrogen atom in the skeletons (6a) and (6b) is not substituted with a linking group together with an adjacent hydrogen atom to form a cyclic structure.

[0208] As one preferable group of compounds having the skeleton (6a), compounds represented by the following general formula (6a) can be exemplified.

##STR00225##

[0209] In the general formula (6a), each of R.sup.59 and R.sup.60 independently represents a substituted or unsubstituted alkyl group. Each of m59 and m60 independently represents an integer of 0 to 4. Each of Y.sup.9 and Y.sup.10 independently represents two hydrogen atoms, a single bond or N(R.sup.27). R.sup.27 represents a hydrogen atom, a deuterium atom, or a substituent. Each of Z.sup.9 to Z.sup.12 independently represents an oxygen atom or a sulfur atom. Each of A.sup.1 and A.sup.2 independently represents a hydrogen atom, a deuterium atom, or a substituent. In relation to details of R.sup.59, R.sup.60, m59, m60, Z.sup.9 to Z.sup.12, A.sup.1, and A.sup.2, descriptions on R.sup.55, R.sup.56, m55, m56, A.sup.1, and A.sup.2 in the general formula (5a) and Z.sup.9 to Z.sup.12 in the skeleton (6a) can be referred to.

[0210] Hereinafter, specific examples of the compound represented by the general formula (6a) will be given. Compounds of the general formula (6a) that can be used in the present invention are not construed as limiting to the following specific examples. In relation to specific examples including X, it is assumed that a compound in which all X's in the molecule are oxygen atoms, and a compound in which all X's in the molecule are sulfur atoms are disclosed, respectively. A compound in which some of X's in the molecule are oxygen atoms, and the rest are sulfur atoms may also be adopted.

##STR00226## ##STR00227## ##STR00228## ##STR00229## ##STR00230## ##STR00231## ##STR00232## ##STR00233## ##STR00234## ##STR00235## ##STR00236## ##STR00237##

[0211] As one preferable group of compounds having the skeleton (6b), compounds represented by the following general formula (6b) can be exemplified.

##STR00238##

[0212] In the general formula (6b), each of R.sup.61 and R.sup.62 independently represents a substituted or unsubstituted alkyl group. Each of m61 and m60 independently represents an integer of 0 to 4. Each of Y.sup.11 and Y.sup.12 independently represents two hydrogen atoms, a single bond or N(R.sup.27). R.sup.27 represents a hydrogen atom, a deuterium atom, or a substituent. Each of Z.sup.13 to Z.sup.16 independently represents an oxygen atom or a sulfur atom. Each of A.sup.1 and A.sup.2 independently represents a hydrogen atom, a deuterium atom, or a substituent. In relation to details of R.sup.61, R.sup.62, m61, m62, Z.sup.13 to Z.sup.16, A.sup.1, and A.sup.2, descriptions on R.sup.59, R.sup.60, m59, m60, A.sup.1, and A.sup.2 in the general formula (6a), and Z.sup.13 to Z.sup.16 in the skeleton (6b) can be referred to.

[0213] Hereinafter, specific examples of the compound represented by the general formula (6b) will be given. Compounds of the general formula (6b) that can be used in the present invention are not construed as limiting to the following specific examples. In relation to specific examples including X, it is assumed that a compound in which all X's in the molecule are oxygen atoms, and a compound in which all X's in the molecule are sulfur atoms are disclosed, respectively. A compound in which some of X's in the molecule are oxygen atoms, and the rest are sulfur atoms may also be adopted.

##STR00239## ##STR00240## ##STR00241## ##STR00242## ##STR00243## ##STR00244##

[0214] A compound in which a benzene ring is fused with a benzene ring to which a boron atom does not directly bond, between two benzene rings forming a carbazole partial structure existing in the general formula (G), can be preferably mentioned. Examples of such a compound include a compound having the following skeleton (7a), and a compound having the following skeleton (7b).

##STR00245##

[0215] In the skeletons (7a) and (7b), each of Y.sup.21 to Y.sup.24 independently represents two hydrogen atoms, a single bond or N(R.sup.27). In relation to details of Y.sup.21 to Y.sup.24, descriptions on Y.sup.1 to Y.sup.4 in the skeletons (4a) and (4b) can be referred to. In one aspect of the present invention, each hydrogen atom in the skeletons (7a) and (7b) is not substituted with a linking group together with an adjacent hydrogen atom to form a cyclic structure.

[0216] As one preferable group of compounds having the skeleton (7a), compounds represented by the following general formula (7a) can be exemplified.

##STR00246##

[0217] In the general formula (7a), each of Ar.sup.71 to Ar.sup.74 independently represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and, for example, a substituted or unsubstituted aryl group can be preferably selected. Each of n71 and n73 independently represents an integer of 0 to 2. Each of n72 and n74 independently represents an integer of 0 to 4. Each of Y.sup.21 and Y.sup.22 independently represents two hydrogen atoms, a single bond or N(R.sup.27). R.sup.27 represents a hydrogen atom, a deuterium atom, or a substituent. Each of A.sup.1 and A.sup.2 independently represents a hydrogen atom, a deuterium atom, or a substituent.

[0218] In one aspect of the present invention, n71 to n74 are integers of 0 to 2. In one aspect of the present invention, n71 and n73 are the same number, and n72 and n74 are the same number. n71 to n74 can be the same number. For example, n71 to n74 can be 0. n71 to n74 can be all 1. Further, for example, n71 and n73 can be 0, and n72 and n74 can be 1. In relation to preferable groups for Ar.sup.71 to Ar.sup.74, A.sup.1, and A.sup.2, corresponding descriptions on Ar.sup.1 to Ar.sup.4, A.sup.1, and A.sup.2 in the general formula (I a) can be referred to.

[0219] Hereinafter, specific examples of the compound represented by the general formula (7a) will be given. Compounds of the general formula (7a) that can be used in the present invention are not construed as limiting to the following specific examples.

##STR00247## ##STR00248## ##STR00249##

[0220] As one preferable group of compounds having the skeleton (7b), compounds represented by the following general formula (7b) can be exemplified.

##STR00250##

[0221] In the general formula (7b), each of Ar.sup.75 to Ar.sup.78 independently represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and, for example, a substituted or unsubstituted aryl group can be preferably selected. Each of n75 and n77 independently represents an integer of 0 to 2. Each of n76 and n78 independently represents an integer of 0 to 4. Each of Y.sup.23 and Y.sup.24 independently represents two hydrogen atoms, a single bond or N(R.sup.27). R.sup.27 represents a hydrogen atom, a deuterium atom, or a substituent. For detailed descriptions of n75 to n78, descriptions on n71 to n74 in the general formula (7a) can be referred to in this order. In relation to preferable groups for Ar.sup.75 to Ar.sup.78, corresponding descriptions on Ar.sup.1 to Ar.sup.4 in the general formula (1a) can be referred to.

[0222] Hereinafter, specific examples of the compound represented by the general formula (7b) will be given. Compounds of the general formula (7b) that can be used in the present invention are not construed as limiting to the following specific examples.

##STR00251## ##STR00252##

[0223] A compound in which a benzene ring is fused with a benzene ring to which a boron atom directly bonds, between two benzene rings forming a carbazole partial structure existing in the general formula (G), can be preferably mentioned. Examples of such a compound include a compound having the following skeleton (8a), and a compound having the following skeleton (8b).

##STR00253##

[0224] In the skeletons (8a) and (8b), each of Y.sup.25 to Y.sup.28 independently represents two hydrogen atoms, a single bond or N(R.sup.27). In relation to details of Y.sup.25 to Y.sup.28, corresponding descriptions for the skeletons (4a) and (4b) can be referred to. In one aspect of the present invention, each hydrogen atom in the skeletons (8a) and (8b) is not substituted with a linking group together with an adjacent hydrogen atom to form a cyclic structure.

[0225] As one preferable group of compounds having the skeleton (8a), compounds represented by the following general formula (8a) can be exemplified.

##STR00254##

[0226] In the general formula (8a), each of Ar.sup.79 and Ar.sup.80 independently represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and, for example, a substituted or unsubstituted aryl group can be preferably selected. Each of R.sup.71 and R.sup.72 independently represents a substituted or unsubstituted alkyl group. Each of m71 and m72 independently represents an integer of 0 to 4. Each of n79 and n80 independently represents an integer of 0 to 4. Each of Y.sup.25 and Y.sup.26 independently represents two hydrogen atoms, a single bond or N(R.sup.27). R.sup.27 represents a hydrogen atom, a deuterium atom, or a substituent. Each of A.sup.1 and A.sup.2 independently represents a hydrogen atom, a deuterium atom, or a substituent.

[0227] In one aspect of the present invention, n79 and n80 are integers of 0 to 2. In one aspect of the present invention, n79 and n80 are the same number, and for example, can be all 0, or can be all 1. In one aspect of the present invention, m71 and m72 are integers of 0 to 2. In one aspect of the present invention, m71 and m72 are the same number, and for example, can be all 0, or can be all 1. In relation to preferable groups for Ar.sup.79, Ar.sup.80, R.sup.71, R.sup.72, A.sup.1, and A.sup.2, corresponding descriptions on Ar.sup.1, Ar.sup.3, R.sup.41, R.sup.42, A.sup.1, and A.sup.2 in the general formula (1a) can be referred to.

[0228] Hereinafter, specific examples of the compound represented by the general formula (8a) will be given. Compounds of the general formula (8a) that can be used in the present invention are not construed as limiting to the following specific examples.

##STR00255##

[0229] As one preferable group of compounds having the skeleton (8b), compounds represented by the following general formula (8b) can be exemplified.

##STR00256##

[0230] In the general formula (8b), each of Ar.sup.81 and Ar.sup.82 independently represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and, for example, a substituted or unsubstituted aryl group can be preferably selected. Each of R.sup.73 and R.sup.74 independently represents a substituted or unsubstituted alkyl group. Each of m73 and m74 independently represents an integer of 0 to 4. Each of n81 and n82 independently represents an integer of 0 to 4. Each of Y.sup.27 and Y.sup.28 independently represents two hydrogen atoms, a single bond or N(R.sup.27). R.sup.27 represents a hydrogen atom, a deuterium atom, or a substituent. Each of A.sup.1 and A.sup.2 independently represents a hydrogen atom, a deuterium atom, or a substituent.

[0231] In relation to detailed descriptions of m73, m74, n81, and n82, descriptions on m71, m72, n79, and n80 in the general formula (8a) can be referred to. In relation to preferable groups for Ar.sup.81, Ar.sup.82, R.sup.73, R.sup.74, A.sup.1, and A.sup.2, corresponding descriptions on Ar.sup.1, Ar.sup.3, R.sup.41, R.sup.42, A.sup.1, and A.sup.2 in the general formula (1a) can be referred to.

[0232] Hereinafter, specific examples of the compound represented by the general formula (8b) will be given. Compounds of the general formula (8b) that can be used in the present invention are not construed as limiting to the following specific examples.

##STR00257##

[0233] A compound in which benzene rings are fused with both of two benzene rings forming a carbazole partial structure existing in the general formula (G) can be preferably mentioned. Examples of such a compound include a compound having the following skeleton (9a), and a compound having the following skeleton (9b).

##STR00258##

[0234] In the skeletons (9a) and (9b), each of Y.sup.29 to Y.sup.32 independently represents two hydrogen atoms, a single bond or N(R.sup.27). In relation to details of Y.sup.29 to Y.sup.32, corresponding descriptions for the skeletons (4a) and (4b) can be referred to. In one aspect of the present invention, each hydrogen atom in the skeletons (9a) and (9b) is not substituted with a linking group together with an adjacent hydrogen atom to form a cyclic structure.

[0235] As one preferable group of compounds having the skeleton (9a), compounds represented by the following general formula (9a) can be exemplified.

##STR00259##

[0236] In the general formula (9a), each of R.sup.75 and R.sup.76 independently represents a substituted or unsubstituted alkyl group. Each of m75 and m76 independently represents an integer of 0 to 4. Each of Y.sup.29 and Y.sup.30 independently represents two hydrogen atoms, a single bond or N(R.sup.27). R.sup.27 represents a hydrogen atom, a deuterium atom, or a substituent. Each of A.sup.1 and A.sup.2 independently represents a hydrogen atom, a deuterium atom, or a substituent. In relation to details of R.sup.75, R.sup.76, m75, m76, A.sup.1, and A.sup.2, descriptions on R.sup.71, R.sup.72, m71, m72, A.sup.1, and A.sup.2 in the general formula (8a) can be referred to.

[0237] Hereinafter, specific examples of the compound represented by the general formula (9a) will be given. Compounds of the general formula (9a) that can be used in the present invention are not construed as limiting to the following specific examples.

##STR00260## ##STR00261## ##STR00262##

[0238] As one preferable group of compounds having the skeleton (9b), compounds represented by the following general formula (9b) can be exemplified.

##STR00263##

[0239] In the general formula (9b), each of R.sup.77 and R.sup.78 independently represents a substituted or unsubstituted alkyl group. Each of m77 and m78 independently represents an integer of 0 to 4. Each of Y.sup.31 and Y.sup.32 independently represents two hydrogen atoms, a single bond or N(R.sup.27). R.sup.27 represents a hydrogen atom, a deuterium atom, or a substituent. Each of A.sup.1 and A.sup.2 independently represents a hydrogen atom, a deuterium atom, or a substituent. In relation to details of R.sup.77, R.sup.78, m77, m78, A.sup.1, and A.sup.2, descriptions on R.sup.71, R.sup.72, m71, m72, A.sup.1, and A.sup.2 in the general formula (8a) can be referred to.

[0240] Hereinafter, specific examples of the compound represented by the general formula (9b) will be given. Compounds of the general formula (9b) that can be used in the present invention are not construed as limiting to the following specific examples.

##STR00264## ##STR00265##

[0241] As the compound represented by the general formula (G), a compound in which four or more carbazole partial structures are included in the molecule is also preferable. As an example of such a compound, a compound having the following skeleton (10) can be exemplified.

##STR00266##

[0242] Each hydrogen atom in the skeleton (10) can be substituted with a deuterium atom or a substituent. Further, it can be substituted with a linking group together with an adjacent hydrogen atom to form a cyclic structure. For details, corresponding descriptions on R.sup.1 to R.sup.26, A.sup.1, and A.sup.2 in the general formula (G) can be referred to. At least one hydrogen atom of a benzene ring forming a carbazole partial structure included in the skeleton (10) is substituted with a substituted or unsubstituted aryl group. In one aspect of the present invention, each hydrogen atom in the skeleton (10) is not substituted with a linking group together with an adjacent hydrogen atom to form a cyclic structure.

[0243] As one preferable group of compounds having the skeleton (10), compounds represented by the following general formula (10) can be exemplified.

##STR00267##

[0244] In the general formula (10), each of Ar.sup.91 to Ar.sup.94 independently represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and, for example, a substituted or unsubstituted aryl group can be preferably selected. Each of n91 and n93 independently represents an integer of 0 to 4, and each of n92 and n94 independently represents an integer of 0 to 3. An ring, a ring, a ring, and a ring can be substituted, and at least one ring is substituted with a substituted or unsubstituted aryl group, is fused with a benzene ring that can be substituted, or is fused with a substituted or unsubstituted furan ring of benzofuran or a substituted or unsubstituted thiophene ring of thiophene. Each of A.sup.1 and A.sup.2 independently represents a hydrogen atom, a deuterium atom, or a substituent.

[0245] In one aspect of the present invention, n91 to n94 are integers of 0 to 2. In one aspect of the present invention, n91 and n93 are the same number, and n92 and n94 are the same number. n91 to n94 can be all the same number, and for example can be all 0, or can be all 1. In relation to preferable groups for Ar.sup.91 to Ar.sup.94, corresponding descriptions on Ar.sup.1 to Ar.sup.4 in the general formula (1a) can be referred to. In one aspect of the present invention, the ring and the ring have the same substituents or have the same fused structures, and the ring and the ring have the same substituents or have the same fused structures. In one aspect of the present invention, both the ring and the ring are substituted with substituted or unsubstituted aryl groups, are fused with benzene rings that can be substituted, or are fused with substituted or unsubstituted furan rings of benzofuran or substituted or unsubstituted thiophene rings of thiophene. In one aspect of the present invention, both the ring and the ring are substituted with substituted or unsubstituted aryl groups, are fused with benzene rings that can be substituted, or are fused with substituted or unsubstituted furan rings of benzofuran or substituted or unsubstituted thiophene rings of thiophene. In one aspect of the present invention, all of the ring, the ring, the ring, and the ring are substituted with substituted or unsubstituted aryl groups, are fused with benzene rings that can be substituted, or are fused with substituted or unsubstituted furan rings of benzofuran or substituted or unsubstituted thiophene rings of thiophene. For descriptions and preferable ranges of A.sup.1 and A.sup.2, corresponding descriptions on the general formula (G) can be referred to.

[0246] Hereinafter, specific examples of the compound represented by the general formula (10) will be given. Compounds of the general formula (10) that can be used in the present invention are not construed as limiting to the following specific examples.

##STR00268## ##STR00269## ##STR00270## ##STR00271## ##STR00272## ##STR00273## ##STR00274## ##STR00275##

[0247] The compound represented by the general formula (G) can have a skeleton having no symmetry. For example, it can be a compound having an asymmetric skeleton such as the following skeleton (11a) or the following skeleton (11b).

##STR00276##

[0248] In the skeletons (11a) and (11b), each of Z.sup.17 and Z.sup.18 independently represents an oxygen atom or a sulfur atom. In one aspect of the present invention, each hydrogen atom in the skeletons (11a) and (11b) is not substituted with a linking group together with an adjacent hydrogen atom to form a cyclic structure.

[0249] As one preferable group of compounds having the skeleton (11a), compounds represented by the following general formula (11a) can be exemplified.

##STR00277##

[0250] In the general formula (11a), each of Ar.sup.83 to Ar.sup.85 independently represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and, for example, a substituted or unsubstituted aryl group can be preferably selected. Each of R.sup.83 and R.sup.84 independently represents a substituted or unsubstituted alkyl group. Z.sup.17 represents an oxygen atom or a sulfur atom. Each of m83 and m84 independently represents an integer of 0 to 5. n83 represents an integer of 0 to 4, and each of n84 and n85 independently represents an integer of 0 to 3.

[0251] For detailed descriptions and preferable ranges of Ar.sup.83 to Ar.sup.85, R.sup.83, R.sup.84, m83, m84, and n83 to n85, descriptions on Ar.sup.1, Ar.sup.2, Ar.sup.4, R.sup.41, R.sup.42, m1, m2, n1, n2, and n4 in the general formula (1a) can be referred to.

[0252] Hereinafter, specific examples of the compound represented by the general formula (11a) will be given. Compounds of the general formula (11a) that can be used in the present invention are not construed as limiting to the following specific examples. In relation to the following specific examples, it is assumed that a compound in which all X's in the molecule are oxygen atoms, and a compound in which all X's in the molecule are sulfur atoms are disclosed, respectively. A compound in which some of X's in the molecule are oxygen atoms, and the rest are sulfur atoms may also be adopted.

##STR00278## ##STR00279##

[0253] As one preferable group of compounds having the skeleton (11b), compounds represented by the following general formula (11b) can be exemplified.

##STR00280##

[0254] In the general formula (11b), each of Ar.sup.86 to Ar.sup.88 independently represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group, and, for example, a substituted or unsubstituted aryl group can be preferably selected. Each of R.sup.86 and R.sup.87 independently represents a substituted or unsubstituted alkyl group. Z.sup.18 represents an oxygen atom or a sulfur atom. Each of m86 and m87 independently represents an integer of 0 to 5. n86 represents an integer of 0 to 4, and each of n87 and n88 independently represents an integer of 0 to 3.

[0255] For detailed descriptions and preferable ranges of Ar.sup.86 to Ar.sup.88, R.sup.86, R.sup.87, m86, m87, and n86 to n88, descriptions on Ar.sup.1, Ar.sup.2, Ar.sup.4, R.sup.41, R.sup.42, m1, m2, n1, n2, and n4 in the general formula (1a) can be referred to.

[0256] Hereinafter, specific examples of the compound represented by the general formula (11b) will be given. Compounds of the general formula (11b) that can be used in the present invention are not construed as limiting to the following specific examples. In relation to the following specific examples, it is assumed that a compound in which all X's in the molecule are oxygen atoms, and a compound in which all X's in the molecule are sulfur atoms are disclosed, respectively. A compound in which some of X's in the molecule are oxygen atoms, and the rest are sulfur atoms may also be adopted.

##STR00281##

[0257] As the compound represented by the general formula (G), a compound in which R.sup.5 is a donor group can be preferably adopted. The compound in which R.sup.5 is a donor group has a high molar coefficient extinction, and thus tends to have a high luminous efficiency. For example, it exhibits excellent luminescence characteristics as compared to a compound in which R.sup.3 is a donor group. In one preferred aspect of the present invention, R.sup.3 is not a donor group. In one preferred aspect of the present invention, among R.sup.1 to R.sup.7, only R.sup.5 is a donor group, or none of them is a donor group (in particular, a donor group having a p value of 0.2 or less). The donor group is a group having a negative Hammett's p value. The p value of the donor group for R.sup.5 is preferably 0.2 or less, and can be, for example, 0.4 or less, or can be, for example, 0.6 or less. As a preferable donor group, a substituted amino group can be mentioned, and a substituted or unsubstituted diarylamino group is preferable. The aryl group can be a monocycle, or can be a fused ring in which two or more rings are fused. In the case of a fused ring, the number of rings after fusing is preferably two to six, and, for example, can be selected from two to four, or can be two. Two aryl groups constituting the diarylamino group can be the same or different. Further, the two aryl groups can be linked by a single bond or a linking group. As the substituted or unsubstituted diarylamino group, a substituted or unsubstituted diphenyl amino group is preferable. A substituted or unsubstituted carbazol-9-yl group in which two phenyl groups bond by a single bond can be adopted, or a substituted or unsubstituted diphenyl amino group in which two phenyl groups are not bonded by a single bond can be adopted. When any of R.sup.1 to R.sup.7 in the general formula (G) is a substituted amino group, preferably at least R.sup.5 is a substituted amino group, more preferably only R.sup.5 is a substituted amino group. In one aspect of the present invention, R.sup.3 is not a substituted amino group.

[0258] When R.sup.5 is a donor group, and X.sup.1 is a nitrogen atom, it is preferable that R.sup.16 or R.sup.19 is a donor group, and it is more preferable that R.sup.19 is a donor group. Here, all of the rest of R.sup.1 to R.sup.26 can be, for example, hydrogen atoms or deuterium atoms. For example, at least one of R.sup.3, R.sup.6, R.sup.15, and R.sup.20 can be a substituent (preferably, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group) and the others can be hydrogen atoms or deuterium atoms.

[0259] When R.sup.5 is a donor group, and X.sup.1 is a boron atom, it is preferable that R.sup.20 or R.sup.23 is a donor group, and it is more preferable that R.sup.20 is a donor group. Here, all of the rest of R.sup.1 to R.sup.26 can be, for example, hydrogen atoms or deuterium atoms. For example, at least one of R.sup.3, R.sup.6, R.sup.19, and R.sup.24 can be a substituent (preferably, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group) and the others can be hydrogen atoms or deuterium atom.

[0260] As one preferable group of compounds in which R.sup.5 is a donor group, a compound represented by the following general formula (12a) and a compound represented by the following general formula (12b) can be exemplified.

##STR00282##

[0261] In the general formula (12a) and the general formula (12b), each of Ar.sup.1 to Ar.sup.8 independently represents a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted alkyl group. For example, a substituted or unsubstituted alkyl group can be preferably selected, or a substituted or unsubstituted aryl group can be preferably selected. R.sup.5 represents a donor group. Each of R.sup.41 to R.sup.44 independently represents a substituted or unsubstituted alkyl group. Each of m1 to m4 independently represents an integer of 0 to 5. Each of n1, n3, n5, and n7 independently represents an integer of 0 to 4, n4 and n8 represent integers of 0 to 3, and n2 and n6 represent integers of 0 to 2. Each of A.sup.1 and A.sup.2 independently represents a hydrogen atom, a deuterium atom, or a substituent. In relation to details of Ar.sup.1 to Ar.sup.8, R.sup.41 to R.sup.44, m1 to m4, n1, n3 to n5, n7, n8, A.sup.1, and A.sup.2, the corresponding descriptions for the general formula (1a) and the general formula (1b) can be referred to. Meanwhile, Ar.sup.1's bonded to adjacent carbon atoms, Ar.sup.3's bonded to adjacent carbon atoms, Ar.sup.5's bonded to adjacent carbon atoms, and Ar.sup.7's bonded to adjacent carbon atoms can be bonded to each other to form cyclic structures. Preferably, benzofuran (fused as a furan ring) or benzothiophene (fused as a thiophene ring) can be formed.

[0262] Hereinafter, specific examples of the compounds represented by the general formula (12a) and the general formula (12b) will be given. Meanwhile, compounds of the general formula (12a) and the general formula (12b), which can be used in the present invention, are not construed as limiting to the following specific examples. In the following specific examples, R, Ar, and X in the formulas F1 to F56 are specified in the table so that the structure of each compound is defined. R is selected from A to D described below, Ar is selected from a to d described below, and X is selected from a to . For example, the No. 1 compound in the table is a compound of the formula F1, which has a structure in which R is A, and Ar is a.

##STR00283## ##STR00284## ##STR00285## ##STR00286## ##STR00287## ##STR00288## ##STR00289## ##STR00290## ##STR00291## ##STR00292## ##STR00293## ##STR00294## ##STR00295## ##STR00296## ##STR00297## ##STR00298##

TABLE-US-00002 TABLE 2 No. F R Ar 1 F1 A a 2 F1 A b 3 F1 A c 4 F1 A d 5 F1 B a 6 F1 B b 7 F1 B c 8 F1 B d 9 F1 C a 10 F1 C b 11 F1 C c 12 F1 C d 13 F1 D a 14 F1 D b 15 F1 D c 16 F1 D d 17 F2 A a 18 F2 A b 19 F2 A c 20 F2 A d 21 F2 B a 22 F2 B b 23 F2 B c 24 F2 B d 25 F2 C a 26 F2 C b 27 F2 C c 28 F2 C d 29 F3 A a 30 F3 A b 31 F3 A c 32 F3 A d 33 F3 B a 34 F3 B b 35 F3 B c 36 F3 B d 37 F3 C a 38 F3 C b 39 F3 C c 40 F3 C d 41 F4 A a 42 F4 A b 43 F4 A c 44 F4 A d 45 F4 B a 46 F4 B b 47 F4 B c 48 F4 B d 49 F4 C a 50 F4 C b 51 F4 C c 52 F4 C d 53 F4 D a 54 F4 D b 55 F4 D c 56 F4 D d 57 F5 A a 58 F5 A b 59 F5 A c 60 F5 A d 61 F5 B a 62 F5 B b 63 F5 B c 64 F5 B d 65 F5 C a 66 F5 C b 67 F5 C c 68 F5 C d 69 F6 A a 70 F6 A b 71 F6 A c 72 F6 A d 73 F6 B a 74 F6 B b 75 F6 B c 76 F6 B d 77 F6 C a 78 F6 C b 79 F6 C c 80 F6 C d 81 F7 A a 82 F7 A b 83 F7 A c 84 F7 A d 85 F7 B a 86 F7 B b 87 F7 B c 88 F7 B d 89 F7 C a 90 F7 C b 91 F7 C c 92 F7 C d 93 F7 D a 94 F7 D b 95 F7 D c 96 F7 D d 97 F8 A a 98 F8 A b 99 F8 A c 100 F8 A d 101 F8 B a 102 F8 B b 103 F8 B c 104 F8 B d 105 F8 C a 106 F8 C b 107 F8 C c 108 F8 C d 109 F9 A a 110 F9 A b 111 F9 A c 112 F9 A d 113 F9 B a 114 F9 B b 115 F9 B c 116 F9 B d 117 F9 C a 118 F9 C b 119 F9 C c 120 F9 C d 121 F10 A a 122 F10 A b 123 F10 A c 124 F10 A d 125 F10 B a 126 F10 B b 127 F10 B c 128 F10 B d 129 F10 C a 130 F10 C b 131 F10 C c 132 F10 C d 133 F10 D a 134 F10 D b 135 F10 D c 136 F10 D d 137 F11 A a 138 F11 A b 139 F11 A c 140 F11 A d 141 F11 B a 142 F11 B b 143 F11 B c 144 F11 B d 145 F11 C a 146 F11 C b 147 F11 C c 148 F11 C d 149 F12 A a 150 F12 A b 151 F12 A c 152 F12 A d 153 F12 B a 154 F12 B b 155 F12 B c 156 F12 B d 157 F12 C a 158 F12 C b 159 F12 C c 160 F12 C d 161 F13 A a 162 F13 A b 163 F13 A c 164 F13 A d 165 F13 B a 166 F13 B b 167 F13 B c 168 F13 B d 169 F13 C a 170 F13 C b 171 F13 C c 172 F13 C d 173 F13 D a 174 F13 D b 175 F13 D c 176 F13 D d 177 F14 A a 178 F14 A b 179 F14 A c 180 F14 A d 181 F14 B a 182 F14 B b 183 F14 B c 184 F14 B d 185 F14 C a 186 F14 C b 187 F14 C c 188 F14 C d 189 F15 A a 190 F15 A b 191 F15 A c 192 F15 A d 193 F15 B a 194 F15 B b 195 F15 B c 196 F15 B d 197 F15 C a 198 F15 C b 199 F15 C c 200 F15 C d 201 F16 A a 202 F16 A b 203 F16 A c 204 F16 A d 205 F16 B a 206 F16 B b 207 F16 B c 208 F16 B d 209 F16 C a 210 F16 C b 211 F16 C c 212 F16 C d 213 F16 D a 214 F16 D b 215 F16 D c 216 F16 D d 217 F17 A a 218 F17 A b 219 F17 A c 220 F17 A d 221 F17 B a 222 F17 B b 223 F17 B c 224 F17 B d 225 F17 C a 226 F17 C b 227 F17 C c 228 F17 C d 229 F18 A a 230 F18 A b 231 F18 A c 232 F18 A d 233 F18 B a 234 F18 B b 235 F18 B c 236 F18 B d 237 F18 C a 238 F18 C b 239 F18 C c 240 F18 C d 241 F19 A a 242 F19 A b 243 F19 A c 244 F19 A d 245 F19 B a 246 F19 B b 247 F19 B c 248 F19 B d 249 F19 C a 250 F19 C b 251 F19 C c 252 F19 C d 253 F19 D a 254 F19 D b 255 F19 D c 256 F19 D d 257 F20 A a 258 F20 A b 259 F20 A c 260 F20 A d 261 F20 B a 262 F20 B b 263 F20 B c 264 F20 B d 265 F20 C a 266 F20 C b 267 F20 C c 268 F20 C d 269 F21 A a 270 F21 A b 271 F21 A c 272 F21 A d 273 F21 B a 274 F21 B b 275 F21 B c 276 F21 B d 277 F21 C a 278 F21 C b 279 F21 C c 280 F21 C d 281 F22 A a 282 F22 A b 283 F22 A c 284 F22 A d 285 F22 B a 286 F22 B b 287 F22 B c 288 F22 B d 289 F22 C a 290 F22 C b 291 F22 C c 292 F22 C d 293 F22 D a 294 F22 D b 295 F22 D c 296 F22 D d 297 F23 A a 298 F23 A b 299 F23 A c 300 F23 A d 301 F23 B a 302 F23 B b 303 F23 B c 304 F23 B d 305 F23 C a 306 F23 C b 307 F23 C c 308 F23 C d 309 F24 A a 310 F24 A b 311 F24 A c 312 F24 A d 313 F24 B a 314 F24 B b 315 F24 B c 316 F24 B d 317 F24 C a 318 F24 C b 319 F24 C c 320 F24 C d 321 F25 A a 322 F25 A b 323 F25 A c 324 F25 A d 325 F25 B a 326 F25 B b 327 F25 B c 328 F25 B d 329 F25 C a 330 F25 C b 331 F25 C c 332 F25 C d 333 F25 D a 334 F25 D b 335 F25 D c 336 F25 D d 337 F26 A a 338 F26 A b 339 F26 A c 340 F26 A d 341 F26 B a 342 F26 B b 343 F26 B c 344 F26 B d 345 F26 C a 346 F26 C b 347 F26 C c 348 F26 C d 349 F27 A a 350 F27 A b 351 F27 A c 352 F27 A d 353 F27 B a 354 F27 B b 355 F27 B c 356 F27 B d 357 F27 C a 358 F27 C b 359 F27 C c 360 F27 C d 361 F28 A a 362 F28 A b 363 F28 A c 364 F28 A d 365 F28 B a 366 F28 B b 367 F28 B c 368 F28 B d 369 F28 C a 370 F28 C b 371 F28 C c 372 F28 C d 373 F28 D a 374 F28 D b 375 F28 D c 376 F28 D d 377 F29 A a 378 F29 A b 379 F29 A c 380 F29 A d 381 F29 B a 382 F29 B b 383 F29 B c 384 F29 B d 385 F29 C a 386 F29 C b 387 F29 C c 388 F29 C d 389 F30 A a 390 F30 A b 391 F30 A c 392 F30 A d 393 F30 B a 394 F30 B b 395 F30 B c 396 F30 B d 397 F30 C a 398 F30 C b 399 F30 C c 400 F30 C d 401 F31 A a 402 F31 A b 403 F31 A c 404 F31 A d 405 F31 B a 406 F31 B b 407 F31 B c 408 F31 B d 409 F31 C a 410 F31 C b 411 F31 C c 412 F31 C d 413 F31 D a 414 F31 D b 415 F31 D c 416 F31 D d 417 F32 A a 418 F32 A b 419 F32 A c 420 F32 A d 421 F32 B a 422 F32 B b 423 F32 B c 424 F32 B d 425 F32 C a 426 F32 C b 427 F32 C c 428 F32 C d 429 F33 A a 430 F33 A b 431 F33 A c 432 F33 A d 433 F33 B a 434 F33 B b 435 F33 B c 436 F33 B d 437 F33 C a 438 F33 C b 439 F33 C c 440 F33 C d 441 F34 A a 442 F34 A b 443 F34 A c 444 F34 A d 445 F34 B a 446 F34 B b 447 F34 B c 448 F34 B d 449 F34 C a 450 F34 C b 451 F34 C c 452 F34 C d 453 F34 D a 454 F34 D b 455 F34 D c 456 F34 D d 457 F35 A a 458 F35 A b 459 F35 A c 460 F35 A d 461 F35 B a 462 F35 B b 463 F35 B c 464 F35 B d 465 F35 C a 466 F35 C b 467 F35 C c 468 F35 C d 469 F36 A a 470 F36 A b 471 F36 A c 472 F36 A d 473 F36 B a 474 F36 B b 475 F36 B c 476 F36 B d 477 F36 C a 478 F36 C b 479 F36 C c 480 F36 C d No. F R Ar X 481 F37 A a 482 F37 A a 483 F37 A a 484 F37 A b 485 F37 A b 486 F37 A b 487 F37 A c 488 F37 A c 489 F37 A c 490 F37 A d 491 F37 A d 492 F37 A d 493 F37 B a 494 F37 B a 495 F37 B a 496 F37 B b 497 F37 B b 498 F37 B b 499 F37 B c 500 F37 B c 501 F37 B c 502 F37 B d 503 F37 B d 504 F37 B d 505 F37 C a 506 F37 C a 507 F37 C a 508 F37 C b 509 F37 C b 510 F37 C b 511 F37 C c 512 F37 C c 513 F37 C c 514 F37 C d 515 F37 C d 516 F37 C d 517 F37 D a 518 F37 D a 519 F37 D a 520 F37 D b 521 F37 D b 522 F37 D b 523 F37 D c 524 F37 D c 525 F37 D c 526 F37 D d 527 F37 D d 528 F37 D d 529 F38 A a 530 F38 A a 531 F38 A a 532 F38 A b 533 F38 A b 534 F38 A b 535 F38 A c 536 F38 A c 537 F38 A c 538 F38 A d 539 F38 A d 540 F38 A d 541 F38 B a 542 F38 B a 543 F38 B a 544 F38 B b 545 F38 B b 546 F38 B b 547 F38 B c 548 F38 B c 549 F38 B c 550 F38 B d 551 F38 B d 552 F38 B d 553 F38 C a 554 F38 C a 555 F38 C a 556 F38 C b 557 F38 C b 558 F38 C b 559 F38 C c 560 F38 C c 561 F38 C c 562 F38 C d 563 F38 C d 564 F38 C d 565 F39 A a 566 F39 A a 567 F39 A a 568 F39 A b 569 F39 A b 570 F39 A b 571 F39 A c 572 F39 A c 573 F39 A c 574 F39 A d 575 F39 A d 576 F39 A d 577 F39 B a 578 F39 B a 579 F39 B a 580 F39 B b 581 F39 B b 582 F39 B b 583 F39 B c 584 F39 B c 585 F39 B c 586 F39 B d 587 F39 B d 588 F39 B d 589 F39 C a 590 F39 C a 591 F39 C a 592 F39 C b 593 F39 C b 594 F39 C b 595 F39 C c 596 F39 C c 597 F39 C c 598 F39 C d 599 F39 C d 600 F39 C d 601 F40 A a 602 F40 A a 603 F40 A a 604 F40 A b 605 F40 A b 606 F40 A b 607 F40 A c 608 F40 A c 609 F40 A c 610 F40 A d 611 F40 A d 612 F40 A d 613 F40 B a 614 F40 B a 615 F40 B a 616 F40 B b 617 F40 B b 618 F40 B b 619 F40 B c 620 F40 B c 621 F40 B c 622 F40 B d 623 F40 B d 624 F40 B d 625 F40 C a 626 F40 C a 627 F40 C a 628 F40 C b 629 F40 C b 630 F40 C b 631 F40 C c 632 F40 C c 633 F40 C c 634 F40 C d 635 F40 C d 636 F40 C d 637 F40 D a 638 F40 D a 639 F40 D a 640 F40 D b 641 F40 D b 642 F40 D b 643 F40 D c 644 F40 D c 645 F40 D c 646 F40 D d 647 F4 D d 648 F40 D d 649 F41 A a 650 F41 A a 651 F41 A a 652 F41 A b 653 F41 A b 654 F41 A b 655 F41 A c 656 F41 A c 657 F41 A c 658 F41 A d 659 F41 A d 660 F41 A d 661 F41 B a 662 F41 B a 663 F41 B a 664 F41 B b 665 F41 B b 666 F41 B b 667 F41 B c 668 F41 B c 669 F41 B c 670 F41 B d 671 F41 B d 672 F41 B d 673 F41 C a 674 F41 C a 675 F41 C a 676 F41 C b 677 F41 C b 678 F41 C b 679 F41 C c 680 F41 C c 681 F41 C c 682 F41 C d 683 F41 C d 684 F41 C d 685 F42 A a 686 F42 A a 687 F42 A a 688 F42 A b 689 F42 A b 690 F42 A b 691 F42 A c 692 F42 A c 693 F42 A c 694 F42 A d 695 F42 A d 696 F42 A d 697 F42 B a 698 F42 B a 699 F42 B a 700 F42 B b 701 F42 B b 702 F42 B b 703 F42 B c 704 F42 B c 705 F42 B c 706 F42 B d 707 F42 B d 708 F42 B d 709 F42 C a 710 F42 C a 711 F42 C a 712 F42 C b 713 F42 C b 714 F42 C b 715 F42 C c 716 F42 C c 717 F42 C c 718 F42 C d 719 F42 C d 720 F42 C d 721 F43 A a 722 F43 A a 723 F43 A a 724 F43 A b 725 F43 A b 726 F43 A b 727 F43 A c 728 F43 A c 729 F43 A c 730 F43 A d 731 F43 A a 732 F43 A a 733 F43 B a 734 F43 B a 735 F43 B a 736 F43 B b 737 F43 B b 738 F43 B b 739 F43 B c 740 F43 B c 741 F43 B c 742 F43 B d 743 F43 B d 744 F43 B d 745 F43 C a 746 F43 C a 747 F43 C a 748 F43 C b 749 F43 C b 750 F43 C b 751 F43 C c 752 F43 C c 753 F43 C c 754 F43 C d 755 F43 C d 756 F43 C d 757 F43 D a 758 F43 D a 759 F43 D a 760 F43 D b 761 F43 D b 762 F43 D b 763 F43 D c 764 F43 D c 765 F43 D c 766 F43 D d 767 F43 D d 768 F43 D d 769 F44 A a 770 F44 A a 771 F44 A a 772 F44 A b 773 F44 A b 774 F44 A b 775 F44 A c 776 F44 A c 777 F44 A c 778 F44 A d 779 F44 A d 780 F44 A d 781 F44 B a 782 F44 B a 783 F44 B a 784 F44 B b 785 F44 B b 786 F44 B b 787 F44 B c 788 F44 B c 789 F44 B c 790 F44 B d 791 F44 B d 792 F44 B d 793 F44 C a 794 F44 C a 795 F44 C a 796 F44 C b 797 F44 C b 798 F44 C b 799 F44 C c 800 F44 C c 801 F44 C c 802 F44 C d 803 F44 C d 804 F44 C d 805 F45 A a 806 F45 A a 807 F45 A a 808 F45 A b 809 F45 A b 810 F45 A b 811 F45 A c 812 F45 A c 813 F45 A c 814 F45 A d 815 F45 A d 816 F45 A d 817 F45 B a 818 F45 B a 819 F45 B a 820 F45 B b 821 F45 B b 822 F45 B b 823 F45 B c 824 F45 B c 825 F45 B c 826 F45 B d 827 F45 B d 828 F45 B d 829 F45 C a 830 F45 C a 831 F45 C a 832 F45 C b 833 F45 C b 834 F45 C b 835 F45 C c 836 F45 C c 837 F45 C c 838 F45 C d 839 F45 C d 840 F45 C d 841 F46 A a 842 F46 A a 843 F46 A a 844 F46 A b 845 F46 A b 846 F46 A b 847 F46 A c 848 F46 A c 849 F46 A c 850 F46 A d 851 F46 A d 852 F46 A d 853 F46 B a 854 F46 B a 855 F46 B a 856 F46 B b 857 F46 B b 858 F46 B b 859 F46 B c 860 F46 B c 861 F46 B c 862 F46 B d 863 F46 B d 864 F46 B d 865 F46 C a 866 F46 C a 867 F46 C a 868 F46 C b 869 F46 C b 870 F46 C b 871 F46 C c 872 F46 C c 873 F46 C c 874 F46 C d 875 F46 C d 876 F46 C d 877 F46 D a 878 F46 D a 879 F46 D a 880 F46 D b 881 F46 D b 882 F46 D b 883 F46 D c 884 F46 D c 885 F46 D c 886 F46 D d 887 F46 D d 888 F46 D d 889 F47 A a 890 F47 A a 891 F47 A a 892 F47 A b 893 F47 A b 894 F47 A b 895 F47 A c 896 F47 A c 897 F47 A c 898 F47 A d 899 F47 A d 900 F47 A d 901 F47 B d 902 F47 B a 903 F47 B a 904 F47 B b 905 F47 B b 906 F47 B b 907 F47 B c 908 F47 B c 909 F47 B c 910 F47 B d 911 F47 B d 912 F47 B d 913 F47 C a 914 F47 C a 915 F47 C a 916 F47 C b 917 F47 C b 918 F47 C b 919 F47 C c 920 F47 C c 921 F47 C c 922 F47 C d 923 F47 C d 924 F47 C d 925 F48 A a 926 F48 A a 927 F48 A a 928 F48 A b 929 F48 A b 930 F48 A b 931 F48 A c 932 F48 A c 933 F48 A c 934 F48 A d 935 F48 A d 936 F48 A d 937 F48 B a 938 F48 B a 939 F48 B a 940 F48 B b 941 F48 B b 942 F48 B b 943 F48 B c 944 F48 B c 945 F48 B c 946 F48 B d 947 F48 B d 948 F48 B d 949 F48 C a 950 F48 C a 951 F48 C a 952 F48 C b 953 F48 C b 954 F48 C b 955 F48 C c 956 F48 C c 957 F48 C c 958 F48 C d 959 F48 C d 960 F48 C d 961 F49 A a 962 F49 A a 963 F49 A a 964 F49 A b 965 F49 A b 966 F49 A b 967 F49 A c 968 F49 A c 969 F49 A c 970 F49 A d 971 F49 A d 972 F49 A d 973 F49 B a 974 F49 B a 975 F49 B a 976 F49 B b 977 F49 B b 978 F49 B b 979 F49 B c 980 F49 B c 981 F49 B c 982 F49 B d 983 F49 B d 984 F49 B d 985 F49 C a 986 F49 C a 987 F49 C a 988 F49 C b 989 F49 C b 990 F49 C b 991 F49 C c 992 F49 C c 993 F49 C c 994 F49 C d 995 F49 C d 996 F49 C d 997 F49 D a 998 F49 D a 999 F49 D a 1000 F49 D b 1001 F49 D b 1002 F49 D b 1003 F49 D c 1004 F49 D c 1005 F49 D c 1006 F49 D d 1007 F49 D d 1008 F49 D d 1009 F50 A a 1010 F50 A a 1011 F50 A a 1012 F50 A b 1013 F50 A b 1014 F50 A b 1015 F50 A c 1016 F50 A c 1017 F50 A c 1018 F50 A d 1019 F50 A d 1020 F50 A d 1021 F50 B a 1022 F50 B a 1023 F50 B a 1024 F50 B b 1025 F50 B b 1026 F50 B b 1027 F50 B c 1028 F50 B c 1029 F50 B c 1030 F50 B d 1031 F50 B d 1032 F50 B d 1033 F50 C a 1034 F50 C a 1035 F50 C a 1036 F50 C b 1037 F50 C b 1038 F50 C b 1039 F50 C c 1040 F50 C c 1041 F50 C c 1042 F50 C d 1043 F50 C d 1044 F50 C d 1045 F51 A a 1046 F51 A a 1047 F51 A a 1048 F51 A b 1049 F51 A b 1050 F51 A b 1051 F51 A c 1052 F51 A c 1053 F51 A c 1054 F51 A d 1055 F51 A d 1056 F51 A d 1057 F51 B a 1058 F51 B a 1059 F51 B a 1060 F51 B b 1061 F51 B b 1062 F51 B b 1063 F51 B c 1064 F51 B c 1065 F51 B c 1066 F51 B d 1067 F51 B d 1068 F51 B d 1069 F51 C a 1070 F51 C a 1071 F51 C a 1072 F51 C b 1073 F51 C b 1074 F51 C b 1075 F51 C c 1076 F51 C c 1077 F51 C c 1078 F51 C d 1079 F51 C d 1080 F51 C d 1081 F52 A a 1082 F52 A a 1083 F52 A a 1084 F52 A b 1085 F52 A b 1086 F52 A b 1087 F52 A c 1088 F52 A c 1089 F52 A c 1090 F52 A d 1091 F52 A d 1092 F52 A d 1093 F52 B a 1094 F52 B a 1095 F52 B a 1096 F52 B b 1097 F52 B b 1098 F52 B b 1099 F52 B c 1100 F52 B c 1101 F52 B c 1102 F52 B d 1103 F52 B d 1104 F52 B d 1105 F52 C a 1106 F52 C a 1107 F52 C a 1108 F52 C b 1109 F52 C b 1110 F52 C b 1111 F52 C c 1112 F52 C c 1113 F52 C c 1114 F52 C d 1115 F52 C d 1116 F52 C d 1117 F52 D a 1118 F52 D a 1119 F52 D a 1120 F52 D b 1121 F52 D b 1122 F52 D b 1123 F52 D c 1124 F52 D c 1125 F52 D c 1126 F52 D d 1127 F52 D d 1128 F52 D d 1129 F53 A a 1130 F53 A a 1131 F53 A a 1132 F53 A b 1133 F53 A b 1134 F53 A b 1135 F53 A c 1136 F53 A c 1137 F53 A c 1138 F53 A a 1139 F53 A d 1140 F53 A d 1141 F53 B a 1142 F53 B a 1143 F53 B a 1144 F53 B b 1145 F53 B b 1146 F53 B b 1147 F53 B c 1148 F53 B c 1149 F53 B c 1150 F53 B d 1151 F53 B d 1152 F53 B d 1153 F53 C a 1154 F53 C a 1155 F53 C a 1156 F53 C b 1157 F53 C b 1158 F53 C b 1159 F53 C c 1160 F53 C c 1161 F53 C c 1162 F53 C d 1163 F53 C d 1164 F53 C d 1165 F54 A a 1166 F54 A a 1167 F54 A a 1168 F54 A b 1169 F54 A b 1170 F54 A b 1171 F54 A c 1172 F54 A c 1173 F54 A c 1174 F54 A d 1175 F54 A d 1176 F54 A d 1177 F54 B a 1178 F54 B a 1179 F54 B a 1180 F54 B b 1181 F54 B b 1182 F54 B b 1183 F54 B c 1184 F54 B c 1185 F54 B c 1186 F54 B d 1187 F54 B d 1188 F54 B d 1189 F54 C a 1190 F54 C a 1191 F54 C a 1192 F54 C b 1193 F54 C b 1194 F54 C b 1195 F54 C c 1196 F54 C c 1197 F54 C c 1198 F54 C d 1199 F54 C d 1200 F54 C d 1201 F55 A a 1202 F55 A a 1203 F55 A a 1204 F55 A b 1205 F55 A b 1206 F55 A b 1207 F55 A c 1208 F55 A c 1209 F55 A c 1210 F55 A d 1211 F55 A d 1212 F55 A d 1213 F55 B a 1214 F55 B a 1215 F55 B a 1216 F55 B b 1217 F55 B b 1218 F55 B b 1219 F55 B c 1220 F55 B c 1221 F55 B c 1222 F55 B d 1223 F55 B d 1224 F55 B d 1225 F55 C a 1226 F55 C a 1227 F55 C a 1228 F55 C b 1229 F55 C b 1230 F55 C b 1231 F55 C c 1232 F55 C c 1233 F55 C c 1234 F55 C d 1235 F55 C d 1236 F55 C d 1237 F55 D a 1238 F55 D a 1239 F55 D a 1240 F55 D b 1241 F55 D b 1242 F55 D b 1243 F55 D c 1244 F55 D c 1245 F55 D c 1246 F55 D d 1247 F55 D d 1248 F55 D d 1249 F56 A a 1250 F56 A a 1251 F56 A a 1252 F56 A b 1253 F56 A b 1254 F56 A b 1255 F56 A c 1256 F56 A c 1257 F56 A c 1258 F56 A d 1259 F56 A d 1260 F56 A d 1261 F56 B a 1262 F56 B a 1263 F56 B a 1264 F56 B b 1265 F56 B b 1266 F56 B b 1267 F56 B c 1268 F56 B c 1269 F56 B c 1270 F56 B d 1271 F56 B d 1272 F56 B d 1273 F56 C a 1274 F56 C a 1275 F56 C a 1276 F56 C b 1277 F56 C b 1278 F56 C b 1279 F56 C c 1280 F56 C c 1281 F56 C c 1282 F56 C d 1283 F56 C d 1284 F56 C d 1285 F56 D a 1286 F56 D a 1287 F56 D a 1288 F56 D b 1289 F56 D b 1290 F56 D b 1291 F56 D c 1292 F56 D c [00299][00300][00301][00302][00303][00304][00305][00306][00307][00308][00309]

[0263] In one aspect of the present invention, the skeletons (1a) to (12b) are skeletons in which other rings are not further fused. In one aspect of the present invention, the skeletons (1a) to (12b) are skeletons in which other rings can be further fused. Regarding other rings mentioned herein, the above descriptions on the cyclic structures formed by bonding R.sup.1 and R.sup.2, R.sup.2 and R.sup.3, R.sup.3 and R.sup.4, R.sup.4 and R.sup.5, R.sup.5 and R.sup.6, R.sup.6 and R.sup.7, R.sup.8 and R.sup.9, R.sup.9 and R.sup.10, R.sup.10 and R.sup.11, R.sup.11 and R.sup.12, R.sup.13 and R.sup.14, R.sup.14 and R.sup.15, R.sup.15 and R.sup.16, R.sup.16 and R.sup.17, R.sup.18 and R.sup.19, R.sup.19 and R.sup.20, R.sup.20 and R.sup.21, R.sup.22 and R.sup.23, R.sup.23 and R.sup.24, R.sup.24 and R.sup.25, and R.sup.25 and R.sup.26 to each other can be referred to.

[0264] In one aspect of the present invention, A.sup.1 and A.sup.2 in the general formula (G) are acceptor groups. For example, a compound having acceptor groups at positions of A.sup.1 and A.sup.2 and having any of the skeletons (1a) to (12b) can be mentioned. In relation to descriptions and specific examples of the acceptor group, descriptions, and specific examples of the acceptor group for A.sup.1 and A.sup.2 in the general formula (G) can be referred to.

[0265] Hereinafter, specific examples of a compound in which A.sup.1 and A.sup.2 are acceptor groups will be given. The compounds in which A.sup.1 and A.sup.2 are acceptor groups, which can be used in the present invention, are not construed as limiting to the following specific examples. The following specific examples have structures in which both A.sup.1 and A.sup.2 are A, and the structure of each compound is specified by individually specifying the A.

##STR00310## ##STR00311## ##STR00312## ##STR00313## ##STR00314## ##STR00315## ##STR00316## ##STR00317##

##STR00318## ##STR00319## ##STR00320## ##STR00321## ##STR00322## ##STR00323## ##STR00324##

[0266] In one aspect of the present invention, as the compound represented by the general formula (G), a compound having a rotationally symmetric structure is selected. In one aspect of the present invention, as the compound represented by the general formula (G), a compound having an axisymmetric structure is selected. In one aspect of the present invention, as the compound represented by the general formula (G), a compound having an asymmetric structure is selected.

[0267] Specific examples of a compound having an asymmetric skeleton will be given below. The compounds having asymmetric skeletons or the compounds having asymmetric structures, which can be used in the present invention, are not construed as limiting to the following specific examples. In relation to specific examples including X, it is assumed that a compound in which all X's in the molecule are oxygen atoms, and a compound in which all X's in the molecule are sulfur atoms are disclosed, respectively. A compound in which some of X's in the molecule are oxygen atoms, and the rest are sulfur atoms may also be adopted.

##STR00325## ##STR00326## ##STR00327## ##STR00328## ##STR00329## ##STR00330## ##STR00331## ##STR00332## ##STR00333## ##STR00334## ##STR00335## ##STR00336## ##STR00337##

[0268] Hereinafter, specific examples of a compound that has a symmetric skeleton but has an asymmetric structure because a substituent is asymmetrically bonded will be given. The compounds having asymmetric structures, which can be used in the present invention, are not construed as limiting to the following specific examples.

##STR00338## ##STR00339##

[0269] In one aspect of the present invention, R.sup.3 in the general formula (G) is not a diarylamino group (two aryl groups constituting the diarylamino group can be bonded to each other). In one preferred aspect of the present invention, R.sup.3 in the general formula (G) is a hydrogen atom, a deuterium atom, or an acceptor group (not a donor group).

[0270] In one aspect of the present invention, at least one of n1 to n4 in the general formula (1a) is 1 or more. In one preferred aspect of the present invention, at least one of m1 and m2 in the general formula (1a) is 1 or more. In a more preferable aspect of the present invention, at least one of n1 to n4 in the general formula (1a) is 1 or more, and moreover, at least one of m1 and m2 in the general formula (1a) is 1 or more.

[0271] In one aspect of the present invention, at least one of n5 to n8 in the general formula (1b) is 1 or more. In one preferred aspect of the present invention, at least one of m3 and m4 in the general formula (1b) is 1 or more. In a more preferable aspect of the present invention, at least one of n5 to n8 in the general formula (1b) is 1 or more, and moreover, at least one of m3 and m4 in the general formula (1b) is 1 or more.

[0272] When at least one of m1 and m2 is 1 or more, and at least one of m3 and m4 is 1 or more, it is preferable that at least one of R.sup.41 and R.sup.42 and at least one of R.sup.43 and R.sup.44 are alkyl groups which can be substituted with deuterium atoms, and for example, all of R.sup.41 to R.sup.44 are alkyl groups which can be substituted with deuterium atoms. When at least one of n1 to n4 is 1 or more, and at least one of n5 to n8 is 1 or more, it is preferable that at least one of Ar.sup.1 to A.sup.4 and at least one of Ar.sup.5 to Ar.sup.8 are aryl groups which can be substituted with deuterium atoms or alkyl groups, and for example, all of Ar.sup.1 to Ar.sup.8 are aryl groups which can be substituted with deuterium atoms or alkyl groups.

[0273] In one aspect of the present invention, when X.sup.1 in the general formula (G) is a boron atom, and R.sup.8, R.sup.10, R.sup.12, R.sup.13, R.sup.15, and R.sup.17 are alkyl groups (or methyl groups), at least one of R.sup.1 to R.sup.7, R.sup.18 to R.sup.20, and R.sup.23 to R.sup.26 is a substituent, preferably a group of Substituent Group E, and is, for example, an aryl group that can be substituted with a deuterium atom or an alkyl group. In one aspect of the present invention, when X.sup.2 in the general formula (G) is a boron atom, and R.sup.8, R.sup.10, R.sup.12, R.sup.22, R.sup.24, and R.sup.26 are alkyl groups (or methyl groups), at least one of R.sup.1 to R.sup.7, R.sup.13 to R.sup.16, and R.sup.19 to R.sup.21 is a substituent, preferably a group of Substituent Group E, and is, for example, an aryl group that can be substituted with a deuterium atom or an alkyl group.

[0274] In one aspect of the present invention, when X.sup.1 in the general formula (G) is a boron atom, and any one combination of R.sup.8 and R.sup.9, and R.sup.9 and R.sup.10, and any one combination of R.sup.15 and R.sup.16, and R.sup.16 and R.sup.17 bond to each other to form an aromatic ring (or a benzene ring), at least one of R.sup.1 to R.sup.7, R.sup.18 to R.sup.20, and R.sup.23 to R.sup.26 is a substituent, preferably a group of Substituent Group E, and is, for example, an aryl group that can be substituted with a deuterium atom or an alkyl group. In one aspect of the present invention, when X.sup.2 in the general formula (G) is a boron atom, and any one combination of R.sup.8 and R.sup.9, and R.sup.9 and R.sup.10, and any one combination of R.sup.22 and R.sup.23, and R.sup.23 and R.sup.24 bond to each other to form an aromatic ring (or a benzene ring), at least one of R.sup.1 to R.sup.7, R.sup.13 to R.sup.16, and R.sup.19 to R.sup.21 is a substituent, preferably a group of Substituent Group E, and is, for example, an aryl group that can be substituted with a deuterium atom or an alkyl group.

[0275] In one aspect of the present invention, R.sup.9 and R.sup.11 in the general formula (G) are neither cyano groups nor alkyl groups. That is, R.sup.9 and R.sup.11 are hydrogen atoms, deuterium atoms, or substituents other than cyano groups and alkyl groups. In one aspect of the present invention, R.sup.9 and R.sup.11 in the general formula (G) are neither cyano groups nor tert-butyl groups.

[0276] In one preferred aspect of the present invention, at least one of R.sup.8 to R.sup.12 in the general formula (G) is a substituent.

[0277] In one aspect of the present invention, R.sup.3 in the general formula (G) is not a substituted amino group or aryl group. In one aspect of the present invention, R.sup.3 in the general formula (G) is not a substituted amino group or phenyl group. In one aspect of the present invention, R.sup.3 in the general formula (G) is not a dimethyl amino group, a diphenyl amino group, or a phenyl group.

[0278] In one preferred aspect of the present invention, at least one of R.sup.1 to R.sup.26 in the general formula (G) is a substituent. More preferably, at least one of R.sup.1 to R.sup.26 is an alkyl group, and is, for example, an alkyl group having 1 to 4 carbon atoms.

(Substrate)

[0279] In some embodiments, the organic electroluminescent device of the present invention is supported by a substrate, wherein the substrate is not particularly limited and can be any of those that have been commonly used in an organic electroluminescent device, for example those formed of glass, transparent plastics, quartz, and silicon.

(Anode)

[0280] In some embodiments, the anode of the organic electroluminescent device is made of a metal, an alloy, a conductive compound, or a combination thereof. In some embodiments, the metal, alloy, or conductive compound has a large work function (4 eV or more). In some embodiments, the metal is Au. In some embodiments, the conductive transparent material is selected from CuI, indium tin oxide (ITO), SnO.sub.2, and ZnO. In some embodiments, an amorphous material capable of forming a transparent conductive film, such as IDIXO (In.sub.2O.sub.3ZnO), is used. In some embodiments, the anode is a thin film. In some embodiments, the thin film is made by vapor deposition or sputtering. In some embodiments, the film is patterned by a photolithography method. In some embodiments, when the pattern may not require high accuracy (for example, approximately 100 m or more), the pattern can be formed with a mask having a desired shape on vapor deposition or sputtering of the electrode material. In some embodiments, when a material can be applied as a coating material, such as an organic conductive compound, a wet film forming method, such as a printing method and a coating method is used. In some embodiments, when the emitted light goes through the anode, the anode has a transmittance of more than 10%, and the anode has a sheet resistance of several hundred Ohm per square or less. In some embodiments, the thickness of the anode is from 10 to 1,000 nm. In some embodiments, the thickness of the anode is from 10 to 200 nm. In some embodiments, the thickness of the anode varies depending on the material used.

(Cathode)

[0281] In some embodiments, the cathode is made of an electrode material such as a metal having a small work function (4 eV or less) (referred to as an electron injection metal), an alloy, a conductive compound, or a combination thereof. In some embodiments, the electrode material is selected from sodium, a sodium-potassium alloy, magnesium, lithium, a magnesium-copper mixture, a magnesium-silver mixture, a magnesium-aluminum mixture, a magnesium-indium mixture, an aluminum-aluminum oxide (Al.sub.2O.sub.3) mixture, indium, a lithium-aluminum mixture, and a rare earth element. In some embodiments, a mixture of an electron injection metal and a second metal that is a stable metal having a larger work function than the electron injection metal is used. In some embodiments, the mixture is selected from a magnesium-silver mixture, a magnesium-aluminum mixture, a magnesium-indium mixture, an aluminum-aluminum oxide (Al.sub.2O.sub.3) mixture, a lithium-aluminum mixture, and aluminum. In some embodiments, the mixture increases the electron injection property and the durability against oxidation. In some embodiments, the cathode is produced by forming the electrode material into a thin film by vapor deposition or sputtering. In some embodiments, the cathode has a sheet resistance of several hundred Ohm per square or less. In some embodiments, the thickness of the cathode is from 10 nm to 5 m. In some embodiments, the thickness of the cathode is from 50 to 200 nm. In some embodiments, for transmitting the emitted light, any one of the anode and the cathode of the organic electroluminescent device is transparent or translucent. In some embodiments, the transparent or translucent electroluminescent devices enhance the light emission luminance.

[0282] In some embodiments, the cathode is formed with a conductive transparent material, as described for the anode, to form a transparent or translucent cathode. In some embodiments, a device comprises an anode and a cathode, both being transparent or translucent.

(Injection Layer)

[0283] An injection layer is a layer between the electrode and the organic layer. In some embodiments, the injection layer decreases the drive voltage and enhances the light emission luminance. In some embodiments, the injection layer includes a hole injection layer and an electron injection layer. The injection layer can be positioned between the anode and the light emitting layer or the hole transport layer, and between the cathode and the light emitting layer or the electron transport layer. In some embodiments, an injection layer is present. In some embodiments, no injection layer is present.

[0284] Preferred compound examples for use as a hole injection material are shown below.

##STR00340##

[0285] Next, preferred compound examples for use as an electron injection material are shown below. [0286] LiF, CsF,

##STR00341##

(Barrier Layer)

[0287] A barrier layer is a layer capable of inhibiting charges (electrons or holes) and/or excitons present in the light emitting layer from being diffused outside the light emitting layer. In some embodiments, the electron barrier layer is between the light emitting layer and the hole transport layer, and inhibits electrons from passing through the light emitting layer toward the hole transport layer. In some embodiments, the hole barrier layer is between the light emitting layer and the electron transport layer, and inhibits holes from passing through the light emitting layer toward the electron transport layer. In some embodiments, the barrier layer inhibits excitons from being diffused outside the light emitting layer. In some embodiments, the electron barrier layer and the hole barrier layer form an exciton barrier layer. As used in the present description, the term electron barrier layer or exciton barrier layer includes a layer that has the functions of both electron barrier layer and of an exciton barrier layer.

(Hole Barrier Layer)

[0288] A hole barrier layer acts as an electron transport layer. In some embodiments, the hole barrier layer inhibits holes from reaching the electron transport layer while transporting electrons. In some embodiments, the hole barrier layer enhances the recombination probability of electrons and holes in the light emitting layer. The material for the hole barrier layer can be the same materials as the ones described for the electron transport layer.

[0289] Preferred compound examples for use for the hole barrier layer are shown below.

##STR00342##

(Exciton Barrier Layer)

[0290] An exciton barrier layer inhibits excitons generated through recombination of holes and electrons in the light emitting layer from being diffused to the charge transport layer. In some embodiments, the exciton barrier layer enables effective confinement of excitons in the light emitting layer. In some embodiments, the light emission efficiency of the device is enhanced. In some embodiments, the exciton barrier layer is adjacent to the light emitting layer on any of the side of the anode and the side of the cathode, or on both the sides. In some embodiments, when the exciton barrier layer is on the side of the anode, the layer can be between the hole transport layer and the light emitting layer and adjacent to the light emitting layer. In some embodiments, when the exciton barrier layer is on the side of the cathode, the layer can be between the light emitting layer and the cathode and adjacent to the light emitting layer. In some embodiments, a hole injection layer, an electron barrier layer, or a similar layer is between the anode and the exciton barrier layer that is adjacent to the light emitting layer on the side of the anode. In some embodiments, a hole injection layer, an electron barrier layer, a hole barrier layer, or a similar layer is between the cathode and the exciton barrier layer that is adjacent to the light emitting layer on the side of the cathode. In some embodiments, the exciton barrier layer comprises excited singlet energy and excited triplet energy, at least one of which is higher than the excited singlet energy and the excited triplet energy of the light emitting material, respectively.

(Hole Transport Layer)

[0291] The hole transport layer comprises a hole transport material. In some embodiments, the hole transport layer is a single layer. In some embodiments, the hole transport layer comprises a plurality of layers.

[0292] In some embodiments, the hole transport material has one of injection or transport property of holes and barrier property of electrons. In some embodiments, the hole transport material is an organic material. In some embodiments, the hole transport material is an inorganic material. Examples of known hole transport materials that can be used in the present invention include but are not limited to a triazole derivative, an oxadiazole derivative, an imidazole derivative, a carbazole derivative, an indolocarbazole derivative, a polyarylalkane derivative, a pyrazoline derivative, a pyrazolone derivative, a phenylenediamine derivative, an allylamine derivative, an amino-substituted chalcone derivative, an oxazole derivative, a styrylanthracene derivative, a fluorenone derivative, a hydrazone derivative, a stilbene derivative, a silazane derivative, an aniline copolymer and a conductive polymer oligomer (particularly a thiophene oligomer), or a combination thereof. In some embodiments, the hole transport material is selected from a porphyrin compound, an aromatic tertiary amine compound, and a styrylamine compound. In some embodiments, the hole transport material is an aromatic tertiary amine compound. Preferred specific examples of a compound for use as the hole transport material are shown below.

##STR00343## ##STR00344## ##STR00345##

Electron Transport Layer:

[0293] The electron transport layer comprises an electron transport material. In some embodiments, the electron transport layer is a single layer. In some embodiments, the electron transport layer comprises a plurality of layers.

[0294] In some embodiments, the electron transport material needs only to have a function of transporting electrons, which are injected from the cathode, to the light emitting layer. In some embodiments, the electron transport material also functions as a hole barrier material. Examples of the electron transport layer that can be used in the present invention include but are not limited to a nitro-substituted fluorene derivative, a diphenylquinone derivative, a thiopyran dioxide derivative, a carbodiimide, a fluorenylidenemethane derivative, an anthraquinodimethane, an anthrone derivative, an oxadiazole derivative, an azole derivative, an azine derivative, or a combination thereof, or a polymer thereof. In some embodiments, the electron transport material is a thiadiazole derivative, or a quinoxaline derivative. In some embodiments, the electron transport material is a polymer material. Preferred specific examples of a compound for use as the electron transport material are shown below.

##STR00346##

[0295] Preferred examples of compounds usable as materials that can be added to each organic layer are shown below. For example, the addition of a compound as a stabilizing material can be taken into consideration.

##STR00347##

[0296] Hereinabove preferred materials for use in an organic electroluminescent device are specifically shown; however, the materials which can be used in the present invention are not construed as limiting to the exemplary compounds. Compounds that are exemplified as materials having a specific function can also be used as materials having any other function.

[0297] Each organic layer of the organic electroluminescent device can be formed in a wet process. In a wet process, a solution prepared by dissolving a composition containing the compound to constitute an organic layer is applied onto a surface, and then the solvent is removed to form a film. The wet process includes a spin coating method, a slit coating method, an ink jet method (a spraying method), a gravure printing method, an offset printing method and a flexographic printing method, which, however, are not limitative. In the wet process, an appropriate organic solvent capable of dissolving the compound to constitute an organic layer is selected and used. In some embodiments, a substituent (for example, an alkyl group) capable of increasing the solubility in an organic solvent can be introduced into the compound to constitute an organic layer.

[0298] In some embodiments, the organic layer can be formed in a dry process. In some embodiments, a vacuum evaporation method is employable as a dry process, which, however, is not limitative. In the case where a vacuum evaporation method is employed, compounds to constitute organic layers can be co-evaporated from individual evaporation sources, or can be co-evaporated from a single evaporation source formed by mixing the compounds. In the case where a single evaporation source is used, a mixed powder prepared by mixing compound powders can be used, or a compression molded body prepared by compressing the mixed powder can be used, or a mixture prepared by heating and melting the constituent compounds and cooling the resulting melt can be used. In some embodiments, by co-evaporation under the condition where the evaporation rate (weight reduction rate) of the plural compounds contained in a single evaporation source is the same or is nearly the same, an organic layer having a compositional ratio corresponding to the compositional ratio of the plural compounds contained in the evaporation source can be formed. When plural compounds are mixed in the same compositional ratio as the compositional ratio of the organic layer to be formed to prepare an evaporation source, an organic layer having a desired compositional ratio can be formed in a simplified manner. In some embodiments, the temperature at which the compounds to be co-evaporated has the same weight reduction ratio is specifically defined, and the temperature can be employed as the temperature of co-evaporation.

[Devices]

[0299] In some embodiments, the light emitting layers are incorporated into a device. For example, the device includes, but is not limited to an OLED bulb, an OLED lamp, a television screen, a computer monitor, a mobile phone, and a tablet.

[0300] In some embodiments, an electronic device comprises an OLED comprising an anode, a cathode, and at least one organic layer comprising a light emitting layer between the anode and the cathode.

[0301] In some embodiments, compositions described in the present description can be incorporated into various light-sensitive or light-activated devices, such as OLEDs or photoelectronic devices. In some embodiments, the composition can be useful in facilitating charge transfer or energy transfer within a device and/or as a hole transport material. The device can be, for example, an organic light-emitting diode (OLED), an organic integrated circuit (OIC), an organic field-effect transistor (O-FET), an organic thin-film transistor (O-TFT), an organic light-emitting transistor (O-LET), an organic solar cell (OSC), an organic optical detector, an organic photoreceptor, an organic field-quench device (O-FQD), a light-emitting electrochemical cell (LEC) or an organic laser diode (O-laser).

[Bulbs or Lamps]

[0302] In some embodiments, an electronic device comprises an OLED comprising an anode, a cathode, and at least one organic layer comprising a light emitting layer between the anode and the cathode.

[0303] In some embodiments, a device comprises OLEDs that differ in color. In some embodiments, a device comprises an array comprising a combination of OLEDs. In some embodiments, the combination of OLEDs is a combination of three colors (for example, having RGB). In some embodiments, the combination of OLEDs is a combination of colors that are not red, green, or blue (for example, orange and yellow green). In some embodiments, the combination of OLEDs is a combination of two, four, or more colors.

[0304] In some embodiments, a device is an OLED light comprising, [0305] a circuit board having a first side with a mounting surface and an opposing second side, and defining at least one opening; [0306] at least one OLED on the mounting surface, the at least one OLED configured to emanate light, comprising an anode, a cathode, and at least one organic layer comprising a light emitting layer between the anode and the cathode; [0307] a housing for the circuit board; and [0308] at least one connector arranged at an end of the housing, the housing and the connector defining a package adapted for installation in a light fixture.

[0309] In some embodiments, the OLED light comprises a plurality of OLEDs mounted on a circuit board such that light emanates in a plurality of directions. In some embodiments, a portion of the light emanated in a first direction is deflected to emanate in a second direction. In some embodiments, a reflector is used to deflect the light emanated in a first direction.

[Displays or Screens]

[0310] In some embodiments, the light emitting layer in the present invention can be used in a screen or a display. In some embodiments, the compounds in the present invention are deposited onto a substrate using a process including, but not limited to, vacuum evaporation, deposition, vapor deposition, or chemical vapor deposition (CVD). In some embodiments, the substrate is a photoplate structure useful in a two-sided etching that provides a unique aspect ratio pixel. The screen (which may also be referred to as a mask) is used in a process in the manufacturing of OLED displays. The corresponding artwork pattern design facilitates a very steep and narrow tie-bar between the pixels in the vertical direction and a large, sweeping bevel opening in the horizontal direction. This allows the close patterning of pixels needed for high resolution displays while optimizing the chemical vapor deposition onto a TFT backplane.

[0311] The internal patterning of the pixel allows the construction of a three-dimensional pixel opening with varying aspect ratios in the horizontal and vertical directions. Additionally, the use of imaged stripes or halftone circles within the pixel area inhibits etching in specific areas until these specific patterns are undercut and fall off the substrate. At that point, the entire pixel area is subjected to a similar etching rate but the depths are varying depending on the halftone pattern. Varying the size and spacing of the halftone pattern allows etching to be inhibited at different rates within the pixel allowing for a localized deeper etching needed to create steep vertical bevels.

[0312] A preferred material for the deposition mask is invar. Invar is a metal alloy that is cold rolled into long thin sheet in a steel mill. Invar cannot be electrodeposited onto a rotating mandrel as the nickel mask. An appropriate and more cost feasible method for forming the opening areas in the mask used for deposition is through a wet chemical etching.

[0313] In some embodiments, a screen or display pattern is a pixel matrix on a substrate. In some embodiments, a screen or display pattern is fabricated using lithography (for example, having photolithography and e-beam lithography). In some embodiments, a screen or display pattern is fabricated using a wet chemical etching. In further embodiments, a screen or display pattern is fabricated using plasma etching.

[Methods of Manufacturing Devices]

[0314] An OLED display is generally manufactured by forming a large mother panel and then cutting the mother panel in units of cell panels. In general, each of the cell panels on the mother panel is formed by forming a thin film transistor (TFT) including an active layer and a source/drain electrode on a base substrate, applying a planarization film to the TFT, and sequentially forming a pixel electrode, a light emitting layer, a counter electrode, and an encapsulation layer, and then is cut from the mother panel.

[0315] In another aspect, provided herein is a method of manufacturing an organic light-emitting diode (OLED) display, the method comprising: [0316] forming a barrier layer on a base substrate of a mother panel; [0317] forming a plurality of display units in units of cell panels on the barrier layer; [0318] forming an encapsulation layer on each of the display units of the cell panels; and [0319] applying an organic film to an interface portion between the cell panels.

[0320] In some embodiments, the barrier layer is an inorganic film formed of, for example, SiNx, and an edge portion of the barrier layer is covered with an organic film formed of polyimide or acryl. In some embodiments, the organic film helps the mother panel to be softly cut in units of the cell panel.

[0321] In some embodiments, the thin film transistor (TFT) layer includes a light emitting layer, a gate electrode, and a source/drain electrode. Each of the plurality of display units may include a thin film transistor (TFT) layer, a planarization film formed on the TFT layer, and a light-emitting unit formed on the planarization film, wherein the organic film applied to the interface portion is formed of a same material as a material of the planarization film and is formed at a same time as the planarization film is formed. In some embodiments, the light-emitting unit is connected to the TFT layer with a passivation layer and a planarization film therebetween and an encapsulation layer that covers and protects the light-emitting unit. In some embodiments of the method of manufacturing, the organic film is connected to neither the display units nor the encapsulation layer.

[0322] Each of the organic film and the planarization film may include any one of polyimide and acryl. In some embodiments, the barrier layer can be an inorganic film. In some embodiments, the base substrate can be formed of polyimide. The method may further include, before the forming of the barrier layer on one surface of the base substrate formed of polyimide, attaching a carrier substrate formed of a glass material to another surface of the base substrate, and before the cutting along the interface portion, separating the carrier substrate from the base substrate. In some embodiments, the OLED display is a flexible display.

[0323] In some embodiments, the passivation layer is an organic film disposed on the TFT layer to cover the TFT layer. In some embodiments, the planarization film is an organic film formed on the passivation layer. In some embodiments, the planarization film is formed of polyimide or acryl, like the organic film formed on the edge portion of the barrier layer. In some embodiments, the planarization film and the organic film are simultaneously formed when the OLED display is manufactured. In some embodiments, the organic film can be formed on the edge portion of the barrier layer such that a portion of the organic film directly contacts the base substrate and a remaining portion of the organic film contacts the barrier layer while surrounding the edge portion of the barrier layer.

[0324] In some embodiments, the light emitting layer includes a pixel electrode, a counter electrode, and an organic light emitting layer disposed between the pixel electrode and the counter electrode. In some embodiments, the pixel electrode is connected to the source/drain electrode of the TFT layer.

[0325] In some embodiments, when a voltage is applied to the pixel electrode through the TFT layer, an appropriate voltage is formed between the pixel electrode and the counter electrode, and thus the organic light emitting layer emits light, thereby forming an image. Hereinafter, an image forming unit including the TFT layer and the light-emitting unit is referred to as a display unit.

[0326] In some embodiments, the encapsulation layer that covers the display unit and prevents penetration of external moisture can be formed to have a thin film encapsulation structure in which an organic film and an inorganic film are alternately stacked. In some embodiments, the encapsulation layer has a thin film encapsulation structure in which a plurality of thin films are stacked. In some embodiments, the organic film applied to the interface portion is spaced apart from each of the plurality of display units. In some embodiments, the organic film is formed such that a portion of the organic film directly contacts the base substrate and a remaining portion of the organic film contacts the barrier layer while surrounding the edge portion of the barrier layer.

[0327] In some embodiments, the OLED display is flexible and uses the soft base substrate formed of polyimide. In some embodiments, the base substrate is formed on a carrier substrate formed of a glass material, and then the carrier substrate is separated.

[0328] In some embodiments, the barrier layer is formed on a surface of the base substrate opposite to the carrier substrate. In some embodiments, the barrier layer is patterned according to a size of each of the cell panels. For example, while the base substrate is formed over the entire surface of a mother panel, the barrier layer is formed according to a size of each of the cell panels, and thus a groove is formed at an interface portion between the barrier layers of the cell panels. Each of the cell panels can be cut along the groove.

[0329] In some embodiments, the method of manufacture further comprises cutting along the interface portion, wherein a groove is formed in the barrier layer, wherein at least a portion of the organic film is formed in the groove, and wherein the groove does not penetrate into the base substrate. In some embodiments, the TFT layer of each of the cell panels is formed, and the passivation layer which is an inorganic film and the planarization film which is an organic film are disposed on the TFT layer to cover the TFT layer. At the same time as the planarization film formed of, for example, polyimide or acryl is formed, the groove at the interface portion is covered with the organic film formed of, for example, polyimide or acryl. This is to prevent cracks from occurring by allowing the organic film to absorb an impact generated when each of the cell panels is cut along the groove at the interface portion. That is, if the entire barrier layer is entirely exposed without the organic film, an impact generated when each of the cell panels is cut along the groove at the interface portion is transferred to the barrier layer, thereby increasing the risk of cracks. However, in one embodiment, since the groove at the interface portion between the barrier layers is covered with the organic film and the organic film absorbs an impact that would otherwise be transferred to the barrier layer, each of the cell panels can be softly cut and cracks can be prevented from occurring in the barrier layer. In one embodiment, the organic film covering the groove at the interface portion and the planarization film are spaced apart from each other. For example, if the organic film and the planarization film are connected to each other as one layer, since external moisture may penetrate into the display unit through portions where the planarization film and the organic film remain, the organic film and the planarization film are spaced apart from each other such that the organic film is spaced apart from the display unit.

[0330] In some embodiments, the display unit is formed by forming the light-emitting unit, and the encapsulation layer is disposed on the display unit to cover the display unit. As such, once the mother panel is completely manufactured, the carrier substrate that supports the base substrate is separated from the base substrate. In some embodiments, when a laser beam is emitted toward the carrier substrate, the carrier substrate is separated from the base substrate due to a difference in a thermal expansion coefficient between the carrier substrate and the base substrate.

[0331] In some embodiments, the mother panel is cut in units of the cell panels. In some embodiments, the mother panel is cut along an interface portion between the cell panels by using a cutter. In some embodiments, since the groove at the interface portion along which the mother panel is cut is covered with the organic film, the organic film absorbs an impact during the cutting. In some embodiments, cracks can be prevented from occurring in the barrier layer during the cutting.

[0332] In some embodiments, the methods reduce a defect rate of a product and stabilize its quality.

[0333] Another aspect is an OLED display including: a barrier layer that is formed on a base substrate; a display unit that is formed on the barrier layer; an encapsulation layer that is formed on the display unit; and an organic film that is applied to an edge portion of the barrier layer.

EXAMPLES

[0334] The characteristics of the present invention will be explained in more detail with reference to Examples below. The materials, processes, procedures and the like shown below can be appropriately modified unless they deviate from the substance of the present invention. Accordingly, the scope of the present invention is not construed as being limited to the specific examples shown below. Herein under the light emission characteristics were evaluated using a source meter (available from Keithley Instruments Corporation: 2400 series), a semiconductor parameter analyzer (available from Agilent Corporation, E5273A), an optical power meter device (available from Newport Corporation, 1930C), an optical spectroscope (available from Ocean Optics Corporation, USB2000), a spectroradiometer (available from Topcon Corporation, SR-3), and a streak camera (available from Hamamatsu Photonics K.K., Model C4334).

Example 1

[0335] On a glass substrate on which an anode made of indium-tin oxide (ITO) having a film thickness of 50 nm was formed, the following thin films were laminated by a vacuum deposition method at a vacuum degree of 5.010.sup.5 Pa to produce an organic electroluminescent device.

[0336] First, on ITO, HAT-CN was formed to have a thickness of 10 nm, then NPD was formed thereon to have a thickness of 30 nm, and further thereon, Compound 1 was formed to have a thickness of 5 nm. Next, a host material (H50), a delayed fluorescence material (T33), and a light emitting material (E1) were co-deposited from different evaporation sources to form a light emitting layer with a thickness of 35 nm. In that case, the content of the host material was 34.2% by mass, the content of the delayed fluorescent material was 65.0% by mass, and the content of the light emitting material was 0.8% by mass. Next, SF3-TRZ was formed with a thickness of 10 nm, and then, Liq and SF3-TRZ were co-deposited from different evaporation sources to form a layer with a thickness of 30 nm. The contents of Liq and SF3-TRZ in this layer were 30% by mass and 70% by mass, respectively. Further, Liq was formed with a thickness of 2 nm, and then, aluminum (Al) was vapor-deposited with a thickness of 100 nm to form a cathode, and an organic electroluminescence device was thus produced. The device was referred to as EL Device 1.

[0337] An organic electroluminescent device was produced according to the same process as above except that Comparative Compound A was used in place of Compound 1, and this was referred to as Comparative EL Device 1.

[0338] Thus produced each organic electroluminescent device was energized, and delayed fluorescence derived from the light emitting material (E1) was observed. Each organic electroluminescent device was driven at 6.3 mA/cm.sup.2 to measure the initial drive voltage. The measurement results are shown in Table 3. The drive voltage in Table 3 is a relative value based on the drive voltage of Comparative EL Device 1. Each organic electroluminescent device was driven at a current density of 12.6 mA/cm.sup.2, and the time taken until the emission intensity reached 95% at the start of the driving was measured (LT95). The measurement results are shown in Table 3. LT95 in Table 3 is expressed as a relative value, when LT95 of Relative EL Device 1 is defined as 1. The measurement results show that the device using a compound represented by the general formula (1) as an electron barrier material can be driven at a lower drive voltage and can have a remarkably more prolonged device lifetime, than the device using Comparative Compound A that has heretofore been used as an electron barrier material.

TABLE-US-00003 TABLE 3 Electron Barrier Device Number Material Drive Voltage LT95 EL Device 1 Compound 1 0.65 V 2.1 times Comparative EL Comparative Reference 1 Device 1 Compound A

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INDUSTRIAL APPLICABILITY

[0339] The compound represented by the general formula (1) is useful as an electron barrier material, and can be effectively used in an organic semiconductor device. By using the compound of the present invention as an electron barrier layer of an organic electroluminescent device, the drive voltage can be lowered and the device lifetime can be prolonged. Accordingly, the industrial applicability of the present invention is great.