ORGANIC ELECTROLUMINESCENT ELEMENT, COMPOUND, AND ELECTRONIC DEVICE

Abstract

An organic electroluminescence device includes an anode, a cathode, and an emitting layer provided between the anode and the cathode. The emitting layer contains a compound M3 represented by a formula (1-1) or (1-2) and a delayed fluorescent compound M2. The compound M3 and the compound M2 are mutually different in structure. A singlet energy S.sub.1(M3) of the compound M3 and a singlet energy S.sub.1(M2) of the compound M2 satisfy a relationship of S.sub.1(M3)>S.sub.1(M2). In the formulae (1-1) and (1-2), A is a group represented by a formula (11A) or the like, L.sub.1 and L.sub.2 are each independently a single bond or a substituted or unsubstituted arylene group, and Y.sub.1 is an oxygen atom or a sulfur atom.

##STR00001##

Claims

1. An organic electroluminescence device comprising: an anode; a cathode; and an emitting layer provided between the anode and the cathode, wherein the emitting layer comprises a compound M3 represented by a formula (1-1) or (1-2) below and a delayed fluorescent compound M2, the compound M3 and the compound M2 are mutually different in structure, and a singlet energy S.sub.1(M3) of the compound M3 and a singlet energy S.sub.1(M2) of the compound M2 satisfy a relationship expressed by (Numerical Formula 1) below, $\begin{matrix} S_{1} (M 3) > S_{1} (M 2) & (Numerical Formula 1) \end{matrix}$ ##STR00182## where, in the formulae (1-1) and (1-2): A is a group represented by any one of formulae (11A), (11B), (11C), (11D), (11E), and (11F) below; L.sub.1 and L.sub.2 are each independently a single bond, or a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms; Y.sub.1 is an oxygen atom or a sulfur atom; at least one combination of adjacent two or more of R.sub.21 to R.sub.28 are mutually bonded to form a substituted or unsubstituted monocyclic ring, mutually bonded to form a substituted or unsubstituted fused ring, or not mutually bonded; R.sub.21 to R.sub.28 forming neither the substituted or unsubstituted monocyclic ring nor the substituted or unsubstituted fused ring, and R.sub.100 are each independently a hydrogen atom, a halogen atom, a cyano group, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkyl halide group having 1 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 ring carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 30 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 60 ring carbon atoms, a substituted or unsubstituted arylphosphoryl group having 6 to 60 ring carbon atoms, a hydroxy group, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms, a group represented by N(Rz).sub.2, a thiol group, a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 30 ring carbon atoms, a substituted germanium group, a substituted phosphine oxide group, a nitro group, a substituted boryl group, or a substituted or unsubstituted arylthio group having 6 to 30 ring carbon atoms; Rz is a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms, or a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms; two Rz in N(Rz).sub.2 are mutually the same or different; a plurality of R.sub.100 are mutually the same or different; and each * in the formulae (1-1) and (1-2) represents a bonding position to any one of carbon atoms of a six-membered ring to which R.sub.21 to R.sub.24 are bonded, ##STR00183## ##STR00184## where, in the formulae (11A), (11B), (11C), (11D), (11E), and (11F): X.sub.1 is an oxygen atom or a sulfur atom; at least one combination of adjacent two or more of R.sub.11 to R.sub.20 are mutually bonded to form a substituted or unsubstituted monocyclic ring, mutually bonded to form a substituted or unsubstituted fused ring, or not mutually bonded; R.sub.11 to R.sub.20 forming neither the substituted or unsubstituted monocyclic ring nor the substituted or unsubstituted fused ring each independently represent the same as R.sub.21 to R.sub.28 forming neither the substituted or unsubstituted monocyclic ring nor the substituted or unsubstituted fused ring in the formulae (1-1) and (1-2); and each * represents a bonding position.

2. The organic electroluminescence device according to claim 1, wherein the compound M3 is a compound represented by the formula (1-1).

3. The organic electroluminescence device according to claim 1, wherein L.sub.1 and L.sub.2 are each a single bond.

4. The organic electroluminescence device according to claim 1, wherein A is a group represented by the formula (11F).

5. The organic electroluminescence device according to claim 1, wherein Y.sub.1 is an oxygen atom.

6. The organic electroluminescence device according to claim 1, wherein X.sub.1 is a sulfur atom.

7. The organic electroluminescence device according to claim 1, wherein R.sub.21 to R.sub.28 are each a hydrogen atom.

8. The organic electroluminescence device according to claim 1, wherein R.sub.11 to R.sub.20 are each a hydrogen atom.

9. The organic electroluminescence device according to claim 1, wherein R.sub.100 is a hydrogen atom.

10. The organic electroluminescence device according to claim 1, wherein the emitting layer comprises no metal complex.

11. An electronic device comprising the organic electroluminescence device according to claim 1.

12. A compound represented by any one of formulae (100-1) to (100-4) below, ##STR00185## where, in the formulae (100-1) to (100-4): A is a group represented by any one of formulae (11A), (11B), (11C), (11D), (11E), and (11F) below; L.sub.1 and L.sub.2 are each independently a single bond, or a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms; Y.sub.1 is an oxygen atom or a sulfur atom; at least one combination of adjacent two or more of R.sub.21 to R.sub.28 are mutually bonded to form a substituted or unsubstituted monocyclic ring, mutually bonded to form a substituted or unsubstituted fused ring, or not mutually bonded; R.sub.21 to R.sub.28 forming neither the substituted or unsubstituted monocyclic ring nor the substituted or unsubstituted fused ring, and R.sub.100 are each independently a hydrogen atom, a halogen atom, a cyano group, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkyl halide group having 1 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 ring carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 30 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 60 ring carbon atoms, a substituted or unsubstituted arylphosphoryl group having 6 to 60 ring carbon atoms, a hydroxy group, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms, a group represented by N(Rz).sub.2, a thiol group, a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 30 ring carbon atoms, a substituted germanium group, a substituted phosphine oxide group, a nitro group, a substituted boryl group, or a substituted or unsubstituted arylthio group having 6 to 30 ring carbon atoms; Rz is a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms, or a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms; two Rz in N(Rz).sub.2 are mutually the same or different; a plurality of R.sub.100 are mutually the same or different; R.sub.100 in the formula (100-4) is not a group represented by N(Rz).sub.2; and * in the formula (100-4) represents a bonding position to any one of carbon atoms of a six-membered ring to which R.sub.21 to R.sub.24 are bonded, ##STR00186## ##STR00187## where, in the formulae (11A), (11B), (11C), (11D), (11E), and (11F): X.sub.1 is an oxygen atom or a sulfur atom; at least one combination of adjacent two or more of R.sub.11 to R.sub.20 are mutually bonded to form a substituted or unsubstituted monocyclic ring, mutually bonded to form a substituted or unsubstituted fused ring, or not mutually bonded; R.sub.11 to R.sub.20 forming neither the substituted or unsubstituted monocyclic ring nor the substituted or unsubstituted fused ring each independently represent the same as R.sub.21 to R.sub.28 forming neither the substituted or unsubstituted monocyclic ring nor the substituted or unsubstituted fused ring in the formulae (100-1) to (100-4); and each * represents a bonding position.

13. The compound according to claim 12, represented by the formula (100-1), (100-2), or (100-3).

14. The compound according to claim 12, wherein L.sub.1 and L.sub.2 are each a single bond.

15. The compound according to claim 12, wherein A is a group represented by the formula (11F).

16. The compound according to claim 12, wherein Y.sub.1 is an oxygen atom.

17. The compound according to claim 12, wherein X.sub.1 is a sulfur atom.

18. The compound according to claim 12, wherein R.sub.21 to R.sub.28 are each a hydrogen atom.

19. The compound according to claim 12, wherein R.sub.11 to R.sub.20 are each a hydrogen atom.

20. The compound according to claim 12, wherein R.sub.100 is a hydrogen atom.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0045] FIG. 1 schematically illustrates an exemplary arrangement of an organic electroluminescence device according to a first exemplary embodiment of the invention.

[0046] FIG. 2 schematically illustrates an apparatus for measuring transient PL.

[0047] FIG. 3 illustrates an example of decay curves of the transient PL.

[0048] FIG. 4 schematically illustrates a relationship in energy level between a compound M3 and a compound M2 in an emitting layer of an exemplary organic electroluminescence device according to the first exemplary embodiment of the invention.

[0049] FIG. 5 schematically illustrates a relationship in energy level and energy transfer between the compound M3, the compound M2 and a compound M1 in an emitting layer of an exemplary organic electroluminescence device according to a second exemplary embodiment of the invention.

DESCRIPTION OF EMBODIMENT(S)

Definitions

[0050] Herein, a hydrogen atom includes isotope having different numbers of neutrons, specifically, protium, deuterium and tritium.

[0051] In chemical formulae herein, it is assumed that a hydrogen atom (i.e. protium, deuterium and tritium) is bonded to each of bondable positions that are not annexed with signs R or the like or D representing a deuterium.

[0052] Herein, the ring carbon atoms refer to the number of carbon atoms among atoms forming a ring of a compound (e.g., a monocyclic compound, fused-ring compound, crosslinking compound, carbon ring compound, and heterocyclic compound) in which the atoms are bonded to each other to form the ring. When the ring is substituted by a substituent(s), carbon atom(s) contained in the substituent(s) is not counted in the ring carbon atoms. Unless specifically described, the same applies to the ring carbon atoms described later. For instance, a benzene ring has 6 ring carbon atoms, a naphthalene ring has 10 ring carbon atoms, a pyridine ring has 5 ring carbon atoms, and a furan ring has 4 ring carbon atoms. Further, for instance, 9,9-diphenylfluorenyl group has 13 ring carbon atoms and 9,9-spirobifluorenyl group has 25 ring carbon atoms.

[0053] When a benzene ring is substituted by a substituent in a form of, for instance, an alkyl group, the number of carbon atoms of the alkyl group is not counted in the number of the ring carbon atoms of the benzene ring. Accordingly, the benzene ring substituted by an alkyl group has 6 ring carbon atoms. When a naphthalene ring is substituted by a substituent in a form of, for instance, an alkyl group, the number of carbon atoms of the alkyl group is not counted in the number of the ring carbon atoms of the naphthalene ring. Accordingly, the naphthalene ring substituted by an alkyl group has 10 ring carbon atoms.

[0054] Herein, the ring atoms refer to the number of atoms forming a ring of a compound (e.g., a monocyclic compound, fused-ring compound, cross-linking compound, carbon ring compound, and heterocyclic compound) in which the atoms are bonded to each other to form the ring (e.g., monocyclic ring, fused ring, and ring assembly). Atom(s) not forming the ring (e.g., hydrogen atom(s) for saturating the valence of the atom which forms the ring) and atom(s) in a substituent by which the ring is substituted are not counted as the ring atoms. Unless otherwise specified, the same applies to the ring atoms described later. For instance, a pyridine ring has 6 ring atoms, a quinazoline ring has 10 ring atoms, and a furan ring has 5 ring atoms. For instance, the number of hydrogen atom(s) bonded to a pyridine ring or the number of atoms forming a substituent is not counted in the number of the ring atoms of the pyridine ring. Accordingly, a pyridine ring bonded to a hydrogen atom(s) or a substituent(s) has 6 ring atoms. For instance, the hydrogen atom(s) bonded to carbon atom(s) of a quinazoline ring or the atoms forming a substituent are not counted as the quinazoline ring atoms. Accordingly, a quinazoline ring bonded to hydrogen atom(s) or a substituent(s) has 10 ring atoms.

[0055] Herein, XX to YY carbon atoms in the description of substituted or unsubstituted ZZ group having XX to YY carbon atoms represent carbon atoms of an unsubstituted ZZ group and do not include carbon atoms of a substituent(s) of the substituted ZZ group. Herein, YY is larger than XX, XX representing an integer of 1 or more and YY representing an integer of 2 or more.

[0056] Herein, XX to YY atoms in the description of substituted or unsubstituted ZZ group having XX to YY atoms represent atoms of an unsubstituted ZZ group and does not include atoms of a substituent(s) of the substituted ZZ group. Herein, YY is larger than XX, XX representing an integer of 1 or more and YY representing an integer of 2 or more.

[0057] Herein, an unsubstituted ZZ group refers to an unsubstituted ZZ group in a substituted or unsubstituted ZZ group, and a substituted ZZ group refers to a substituted ZZ group in a substituted or unsubstituted ZZ group.

[0058] Herein, the term unsubstituted used in a substituted or unsubstituted ZZ group means that a hydrogen atom(s) in the ZZ group is not substituted with a substituent(s). The hydrogen atom(s) in the unsubstituted ZZ group is protium, deuterium, or tritium.

[0059] Herein, the term substituted used in a substituted or unsubstituted ZZ group means that at least one hydrogen atom in the ZZ group is substituted with a substituent. Similarly, the term substituted used in a BB group substituted by AA group means that at least one hydrogen atom in the BB group is substituted with the AA group.

Substituents Mentioned Herein

[0060] Substituents mentioned herein will be described below.

[0061] An unsubstituted aryl group mentioned herein has, unless otherwise specified herein, 6 to 50, preferably 6 to 30, and more preferably 6 to 18 ring carbon atoms.

[0062] An unsubstituted heterocyclic group mentioned herein has, unless otherwise specified herein, 5 to 50, preferably 5 to 30, and more preferably 5 to 18 ring atoms.

[0063] An unsubstituted alkyl group mentioned herein has, unless otherwise specified herein, 1 to 50, preferably 1 to 20, and more preferably 1 to 6 carbon atoms.

[0064] An unsubstituted alkenyl group mentioned herein has, unless otherwise specified herein, 2 to 50, preferably 2 to 20, and more preferably 2 to 6 carbon atoms.

[0065] An unsubstituted alkynyl group mentioned herein has, unless otherwise specified herein, 2 to 50, preferably 2 to 20, and more preferably 2 to 6 carbon atoms.

[0066] An unsubstituted cycloalkyl group mentioned herein has, unless otherwise specified herein, 3 to 50, preferably 3 to 20, and more preferably 3 to 6 ring carbon atoms.

[0067] An unsubstituted arylene group mentioned herein has, unless otherwise specified herein, 6 to 50, preferably 6 to 30, and more preferably 6 to 18 ring carbon atoms.

[0068] An unsubstituted divalent heterocyclic group mentioned herein has, unless otherwise specified herein, 5 to 50, preferably 5 to 30, and more preferably 5 to 18 ring atoms.

[0069] An unsubstituted alkylene group mentioned herein has, unless otherwise specified herein, 1 to 50, preferably 1 to 20, and more preferably 1 to 6 carbon atoms.

Substituted or Unsubstituted Aryl Group

[0070] Specific examples (specific example group G1) of the substituted or unsubstituted aryl group mentioned herein include unsubstituted aryl groups (specific example group G1A) below and substituted aryl groups (specific example group G1B). (Herein, an unsubstituted aryl group refers to an unsubstituted aryl group in a substituted or unsubstituted aryl group, and a substituted aryl group refers to a substituted aryl group in a substituted or unsubstituted aryl group.) A simply termed aryl group herein includes both of an unsubstituted aryl group and a substituted aryl group.

[0071] The substituted aryl group refers to a group derived by substituting at least one hydrogen atom in an unsubstituted aryl group with a substituent. Examples of the substituted aryl group include a group derived by substituting at least one hydrogen atom in the unsubstituted aryl group in the specific example group G1A below with a substituent, and examples of the substituted aryl group in the specific example group G1B below. It should be noted that the examples of the unsubstituted aryl group and the substituted aryl group mentioned herein are merely exemplary, and the substituted aryl group mentioned herein includes a group derived by further substituting a hydrogen atom bonded to a carbon atom of a skeleton of a substituted aryl group in the specific example group G1B below, and a group derived by further substituting a hydrogen atom of a substituent of the substituted aryl group in the specific example group G1B below.

Unsubstituted Aryl Group (Specific Example Group G1A):

[0072] a phenyl group, p-biphenyl group, m-biphenyl group, o-biphenyl group, p-terphenyl-4-yl group, p-terphenyl-3-yl group, p-terphenyl-2-yl group, m-terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-terphenyl-4-yl group, o-terphenyl-3-yl group, o-terphenyl-2-yl group, 1-naphthyl group, 2-naphthyl group, anthryl group, benzanthryl group, phenanthryl group, benzophenanthryl group, phenalenyl group, pyrenyl group, chrysenyl group, benzochrysenyl group, triphenylenyl group, benzotriphenylenyl group, tetracenyl group, pentacenyl group, fluorenyl group, 9,9-spirobifluorenyl group, benzofluorenyl group, dibenzofluorenyl group, fluoranthenyl group, benzofluoranthenyl group, perylenyl group, and monovalent aryl group derived by removing one hydrogen atom from cyclic structures represented by formulae (TEMP-1) to (TEMP-15) below.

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

Substituted Aryl Group (Specific Example Group G1B):

[0073] an o-tolyl group, m-tolyl group, p-tolyl group, para-xylyl group, meta-xylyl group, ortho-xylyl group, para-isopropylphenyl group, meta-isopropylphenyl group, ortho-isopropylphenyl group, para-t-butylphenyl group, meta-t-butylphenyl group, ortho-t-butylphenyl group, 3,4,5-trimethylphenyl group, 9,9-dimethylfluorenyl group, 9,9-diphenylfluorenyl group, 9,9-bis(4-methylphenyl) fluorenyl group, 9,9-bis(4-isopropylphenyl) fluorenyl group, 9,9-bis(4-t-butylphenyl) fluorenyl group, cyanophenyl group, triphenylsilylphenyl group, trimethylsilylphenyl group, phenylnaphthyl group, naphthylphenyl group, and group derived by substituting at least one hydrogen atom of a monovalent group derived from one of the cyclic structures represented by the formulae (TEMP-1) to (TEMP-15) with a substituent.

Substituted or Unsubstituted Heterocyclic Group

[0074] The heterocyclic group mentioned herein refers to a cyclic group having at least one hetero atom in the ring atoms. Specific examples of the hetero atom include a nitrogen atom, oxygen atom, sulfur atom, silicon atom, phosphorus atom, and boron atom.

[0075] The heterocyclic group mentioned herein is a monocyclic group or a fused-ring group.

[0076] The heterocyclic group mentioned herein is an aromatic heterocyclic group or a non-aromatic heterocyclic group.

[0077] Specific examples (specific example group G2) of the substituted or unsubstituted heterocyclic group mentioned herein include unsubstituted heterocyclic groups (specific example group G2A) and substituted heterocyclic groups (specific example group G2B). (Herein, an unsubstituted heterocyclic group refers to an unsubstituted heterocyclic group in a substituted or unsubstituted heterocyclic group, and a substituted heterocyclic group refers to a substituted heterocyclic group in a substituted or unsubstituted heterocyclic group.) A simply termed heterocyclic group herein includes both of an unsubstituted heterocyclic group and a substituted heterocyclic group.

[0078] The substituted heterocyclic group refers to a group derived by substituting at least one hydrogen atom in an unsubstituted heterocyclic group with a substituent. Specific examples of the substituted heterocyclic group include a group derived by substituting at least one hydrogen atom in the unsubstituted heterocyclic group in the specific example group G2A below with a substituent, and examples of the substituted heterocyclic group in the specific example group G2B below. It should be noted that the examples of the unsubstituted heterocyclic group and the substituted heterocyclic group mentioned herein are merely exemplary, and the substituted heterocyclic group mentioned herein includes a group derived by further substituting a hydrogen atom bonded to a ring atom of a skeleton of a substituted heterocyclic group in the specific example group G2B below, and a group derived by further substituting a hydrogen atom of a substituent of the substituted heterocyclic group in the specific example group G2B below.

[0079] The specific example group G2A includes, for instance, unsubstituted heterocyclic groups including a nitrogen atom (specific example group G2A1) below, unsubstituted heterocyclic groups including an oxygen atom (specific example group G2A2) below, unsubstituted heterocyclic groups including a sulfur atom (specific example group G2A3) below, and monovalent heterocyclic groups (specific example group G2A4) derived by removing a hydrogen atom from cyclic structures represented by formulae (TEMP-16) to (TEMP-33) below.

[0080] The specific example group G2B includes, for instance, substituted heterocyclic groups including a nitrogen atom (specific example group G2B1) below, substituted heterocyclic groups including an oxygen atom (specific example group G2B2) below, substituted heterocyclic groups including a sulfur atom (specific example group G2B3) below, and groups derived by substituting at least one hydrogen atom of the monovalent heterocyclic groups (specific example group G2B4) derived from the cyclic structures represented by formulae (TEMP-16) to (TEMP-33) below.

Unsubstituted Heterocyclic Groups Including Nitrogen Atom (Specific Example Group G2A1):

[0081] a pyrrolyl group, imidazolyl group, pyrazolyl group, triazolyl group, tetrazolyl group, oxazolyl group, isoxazolyl group, oxadiazolyl group, thiazolyl group, isothiazolyl group, thiadiazolyl group, pyridyl group, pyridazynyl group, pyrimidinyl group, pyrazinyl group, triazinyl group, indolyl group, isoindolyl group, indolizinyl group, quinolizinyl group, quinolyl group, isoquinolyl group, cinnolyl group, phthalazinyl group, quinazolinyl group, quinoxalinyl group, benzimidazolyl group, indazolyl group, phenanthrolinyl group, phenanthridinyl group, acridinyl group, phenazinyl group, carbazolyl group, benzocarbazolyl group, morpholino group, phenoxazinyl group, phenothiazinyl group, azacarbazolyl group, and diazacarbazolyl group.

Unsubstituted Heterocyclic Groups Including Oxygen Atom (Specific Example Group G2A2):

[0082] a furyl group, oxazolyl group, isoxazolyl group, oxadiazolyl group, xanthenyl group, benzofuranyl group, isobenzofuranyl group, dibenzofuranyl group, naphthobenzofuranyl group, benzoxazolyl group, benzisoxazolyl group, phenoxazinyl group, morpholino group, dinaphthofuranyl group, azadibenzofuranyl diazadibenzofuranyl group, azanaphthobenzofuranyl group, and group, diazanaphthobenzofuranyl group.

Unsubstituted Heterocyclic Groups Including Sulfur Atom (Specific Example Group G2A3):

[0083] a thienyl group, thiazolyl group, isothiazolyl group, thiadiazolyl group, benzothiophenyl group (benzothienyl group), isobenzothiophenyl group (isobenzothienyl group), dibenzothiophenyl group (dibenzothienyl group), naphthobenzothiophenyl group (nahthobenzothienyl group), benzothiazolyl group, benzisothiazolyl group, phenothiazinyl group, dinaphthothiophenyl group (dinaphthothienyl group), azadibenzothiophenyl group (azadibenzothienyl group), diazadibenzothiophenyl group (diazadibenzothienyl group), azanaphthobenzothiophenyl group (azanaphthobenzothienyl group), and diazanaphthobenzothiophenyl group (diazanaphthobenzothienyl group).
Monovalent Heterocyclic Groups Derived by Removing One Hydrogen Atom from Cyclic Structures Represented by Formulae (TEMP-16) to (TEMP-33) (Specific Example Group G2A4):

##STR00009## ##STR00010## ##STR00011##

[0084] In the formulae (TEMP-16) to (TEMP-33), XA and YA are each independently an oxygen atom, a sulfur atom, NH or CH.sub.2, and at least one of XA or YA is an oxygen atom, a sulfur atom, or NH.

[0085] When at least one of XA or YA in the formulae (TEMP-16) to (TEMP-33) is NH or CH.sub.2, the monovalent heterocyclic groups derived from the cyclic structures represented by the formulae (TEMP-16) to (TEMP-33) include a monovalent group derived by removing one hydrogen atom from NH or CH.sub.2.

[0086] Substituted Heterocyclic Groups Including Nitrogen Atom (Specific Example Group G2B1): [0087] a (9-phenyl) carbazolyl group, (9-biphenylyl) carbazolyl group, (9-phenyl)phenylcarbazolyl group, (9-naphthyl) carbazolyl group, diphenylcarbazole-9-yl group, phenylcarbazole-9-yl group, methylbenzimidazolyl group, ethylbenzimidazolyl group, phenyltriazinyl group, biphenylyltriazinyl group, diphenyltriazinyl group, phenylquinazolinyl group, and biphenylquinazolinyl group.

Substituted Heterocyclic Groups Including Oxygen Atom (Specific Example Group G2B2):

[0088] a phenyldibenzofuranyl group, methyldibenzofuranyl group, t-butyldibenzofuranyl group, and monovalent residue of spiro[9H-xanthene-9,9-[9H]fluorene].

Substituted Heterocyclic Groups Including Sulfur Atom (Specific Example Group G2B3):

[0089] a phenyldibenzothiophenyl group, methyldibenzothiophenyl group, t-butyldibenzothiophenyl group, and monovalent residue of spiro[9H-thioxanthene-9,9-[9H]fluorene].
Groups Obtained by Substituting at Least One Hydrogen Atom of Monovalent Heterocyclic Group Derived from Cyclic Structures Represented by Formulae (TEMP-16) to (TEMP-33) with Substituent (Specific Example Group G2B4):

[0090] The at least one hydrogen atom of a monovalent heterocyclic group means at least one hydrogen atom selected from a hydrogen atom bonded to a ring carbon atom of the monovalent heterocyclic group, a hydrogen atom bonded to a nitrogen atom of at least one of XA or YA in a form of NH, and a hydrogen atom of one of XA and YA in a form of a methylene group (CH.sub.2).

Substituted or Unsubstituted Alkyl Group

[0091] Specific examples (specific example group G3) of the substituted or unsubstituted alkyl group mentioned herein include unsubstituted alkyl groups (specific example group G3A) and substituted alkyl groups (specific example group G3B) below. (Herein, an unsubstituted alkyl group refers to an unsubstituted alkyl group in a substituted or unsubstituted alkyl group, and a substituted alkyl group refers to a substituted alkyl group in a substituted or unsubstituted alkyl group.) A simply termed alkyl group herein includes both of an unsubstituted alkyl group and a substituted alkyl group.

[0092] The substituted alkyl group refers to a group derived by substituting at least one hydrogen atom in an unsubstituted alkyl group with a substituent. Specific examples of the substituted alkyl group include a group derived by substituting at least one hydrogen atom of an unsubstituted alkyl group (specific example group G3A) below with a substituent, and examples of the substituted alkyl group (specific example group G3B) below. Herein, the alkyl group for the unsubstituted alkyl group refers to a chain alkyl group. Accordingly, the unsubstituted alkyl group include linear unsubstituted alkyl group and branched unsubstituted alkyl group. It should be noted that the examples of the unsubstituted alkyl group and the substituted alkyl group mentioned herein are merely exemplary, and the substituted alkyl group mentioned herein includes a group derived by further substituting a hydrogen atom of a skeleton of the substituted alkyl group in the specific example group G3B, and a group derived by further substituting a hydrogen atom of a substituent of the substituted alkyl group in the specific example group G3B.

Unsubstituted Alkyl Group (Specific Example Group G3A):

[0093] a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, and t-butyl group.

Substituted Alkyl Group (Specific Example Group G3B):

[0094] a heptafluoropropyl group (including isomer thereof), pentafluoroethyl group, 2,2,2-trifluoroethyl group, and trifluoromethyl group.

Substituted or Unsubstituted Alkenyl Group

[0095] Specific examples (specific example group G4) of the substituted or unsubstituted alkenyl group mentioned herein include unsubstituted alkenyl groups (specific example group G4A) and substituted alkenyl groups (specific example group G4B). (Herein, an unsubstituted alkenyl group refers to an unsubstituted alkenyl group in a substituted or unsubstituted alkenyl group, and a substituted alkenyl group refers to a substituted alkenyl group in a substituted or unsubstituted alkenyl group.) A simply termed alkenyl group herein includes both of an unsubstituted alkenyl group and a substituted alkenyl group.

[0096] The substituted alkenyl group refers to a group derived by substituting at least one hydrogen atom in an unsubstituted alkenyl group with a substituent. Specific examples of the substituted alkenyl group include an unsubstituted alkenyl group (specific example group G4A) substituted by a substituent, and examples of the substituted alkenyl group (specific example group G4B) below. It should be noted that the examples of the unsubstituted alkenyl group and the substituted alkenyl group mentioned herein are merely exemplary, and the substituted alkenyl group mentioned herein includes a group derived by further substituting a hydrogen atom of a skeleton of the substituted alkenyl group in the specific example group G4B with a substituent, and a group derived by further substituting a hydrogen atom of a substituent of the substituted alkenyl group in the specific example group G4B with a substituent.

[0097] Unsubstituted Alkenyl Group (Specific Example Group G4A): [0098] a vinyl group, allyl group, 1-butenyl group, 2-butenyl group, and 3-butenyl group.

Substituted Alkenyl Group (Specific Example Group G4B):

[0099] a 1,3-butanedienyl group, 1-methylvinyl group, 1-methylallyl group, 1,1-dimethylallyl group, 2-methylallyl group, and 1,2-dimethylallyl group.

Substituted or Unsubstituted Alkynyl Group

[0100] Specific examples (specific example group G5) of the substituted or unsubstituted alkynyl group mentioned herein include unsubstituted alkynyl groups (specific example group G5A) below. (Herein, an unsubstituted alkynyl group refers to an unsubstituted alkynyl group in a substituted or unsubstituted alkynyl group.) A simply termed alkynyl group herein includes both of unsubstituted alkynyl group and substituted alkynyl group.

[0101] The substituted alkynyl group refers to a group derived by substituting at least one hydrogen atom in an unsubstituted alkynyl group with a substituent. Specific examples of the substituted alkynyl group include a group derived by substituting at least one hydrogen atom of the unsubstituted alkynyl group (specific example group G5A) below with a substituent.

Unsubstituted Alkynyl Group (Specific Example Group G5A): An Ethynyl Group

Substituted or Unsubstituted Cycloalkyl Group

[0102] Specific examples (specific example group G6) of the substituted or unsubstituted cycloalkyl group mentioned herein include unsubstituted cycloalkyl groups (specific example group G6A) and substituted cycloalkyl groups (specific example group G6B). (Herein, an unsubstituted cycloalkyl group refers to an unsubstituted cycloalkyl group in a substituted or unsubstituted cycloalkyl group, and a substituted cycloalkyl group refers to a substituted cycloalkyl group in a substituted or unsubstituted cycloalkyl group.) A simply termed cycloalkyl group herein includes both of unsubstituted cycloalkyl group and substituted cycloalkyl group.

[0103] The substituted cycloalkyl group refers to a group derived by substituting at least one hydrogen atom of an unsubstituted cycloalkyl group with a substituent. Specific examples of the substituted cycloalkyl group include a group derived by substituting at least one hydrogen atom of the unsubstituted cycloalkyl group (specific example group G6A) below with a substituent, and examples of the substituted cycloalkyl group (specific example group G6B) below. It should be noted that the examples of the unsubstituted cycloalkyl group and the substituted cycloalkyl group mentioned herein are merely exemplary, and the substituted cycloalkyl group mentioned herein includes a group derived by substituting at least one hydrogen atom bonded to a carbon atom of a skeleton of the substituted cycloalkyl group in the specific example group G6B with a substituent, and a group derived by further substituting a hydrogen atom of a substituent of the substituted cycloalkyl group in the specific example group G6B with a substituent.

Unsubstituted Cycloalkyl Group (Specific Example Group G6A)

[0104] a cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, 1-adamantyl group, 2-adamantyl group, 1-norbornyl group, and 2-norbornyl group.

Substituted Cycloalkyl Group (Specific Example Group G6B):

[0105] a 4-methylcyclohexyl group.
Group Represented by Si(R.sub.901)(R.sub.902)(R.sub.903)

[0106] Specific examples (specific example group G7) of the group represented herein by Si(R.sub.901)(R.sub.902)(R.sub.903) include: Si(G1)(G1)(G1); Si(G1)(G2)(G2); Si(G1)(G1)(G2); Si(G2)(G2)(G2); Si(G3)(G3)(G3); and Si(G6)(G6)(G6); where: [0107] G1 represents a substituted or unsubstituted aryl group in the specific example group G1; [0108] G2 represents a substituted or unsubstituted heterocyclic group in the specific example group G2; [0109] G3 represents a substituted or unsubstituted alkyl group in the specific example group G3; [0110] G6 represents a substituted or unsubstituted cycloalkyl group in the specific example group G6; [0111] a plurality of G1 in Si(G1)(G1)(G1) are mutually the same or different; [0112] a plurality of G2 in Si(G1)(G2)(G2) are mutually the same or different; [0113] a plurality of G1 in Si(G1)(G1)(G2) are mutually the same or different; [0114] a plurality of G2 in Si(G2)(G2)(G2) are mutually the same or different; [0115] a plurality of G3 in Si(G3)(G3)(G3) are mutually the same or different; and [0116] a plurality of G6 in Si(G6)(G6)(G6) are mutually the same or different.

Group Represented by O(R.SUB.904.)

[0117] Specific examples (specific example group G8) of a group represented by O(R.sub.904) herein include: O(G1); O(G2); O(G3); and O(G6); [0118] where: [0119] G1 represents a substituted or unsubstituted aryl group in the specific example group G1; [0120] G2 represents a substituted or unsubstituted heterocyclic group in the specific example group G2; [0121] G3 represents a substituted or unsubstituted alkyl group in the specific example group G3; and [0122] G6 represents a substituted or unsubstituted cycloalkyl group in the specific example group G6.

Group Represented by S(R.SUB.905.)

[0123] Specific examples (specific example group G9) of a group represented herein by S(R.sub.905) include: S(G1); S(G2); S(G3); and S(G6); [0124] where: [0125] G1 represents a substituted or unsubstituted aryl group in the specific example group G1; [0126] G2 represents a substituted or unsubstituted heterocyclic group in the specific example group G2; [0127] G3 represents a substituted or unsubstituted alkyl group in the specific example group G3; and [0128] G6 represents a substituted or unsubstituted cycloalkyl group in the specific example group G6.
Group Represented by N(R.sub.906)(R.sub.907)

[0129] Specific examples (specific example group G10) of a group represented herein by N(R.sub.906)(R.sub.907) include: N(G1)(G1); N(G2)(G2); N(G1)(G2); N(G3)(G3); and N(G6)(G6), [0130] where: [0131] G1 represents a substituted or unsubstituted aryl group in the specific example group G1; [0132] G2 represents a substituted or unsubstituted heterocyclic group in the specific example group G2; [0133] G3 represents a substituted or unsubstituted alkyl group in the specific example group G3; [0134] G6 represents a substituted or unsubstituted cycloalkyl group in the specific example group G6; [0135] a plurality of G1 in N(G1)(G1) are mutually the same or different; [0136] a plurality of G2 in N(G2)(G2) are mutually the same or different; [0137] a plurality of G3 in N(G3)(G3) are mutually the same or different; and [0138] a plurality of G6 in N(G6)(G6) are mutually the same or different.

Halogen Atom

[0139] Specific examples (specific example group G11) of halogen atom mentioned herein include a fluorine atom, chlorine atom, bromine atom, and iodine atom.

Substituted or Unsubstituted Fluoroalkyl Group

[0140] The substituted or unsubstituted fluoroalkyl group mentioned herein refers to a group derived by substituting at least one hydrogen atom bonded to at least one of carbon atoms forming an alkyl group in the substituted or unsubstituted alkyl group with a fluorine atom, and also includes a group (perfluoro group) derived by substituting all of hydrogen atoms bonded to carbon atoms forming the alkyl group in the substituted or unsubstituted alkyl group with fluorine atoms. An unsubstituted fluoroalkyl group has, unless otherwise specified herein, 1 to 50, preferably 1 to 30, more preferably 1 to 18 carbon atoms. The substituted fluoroalkyl group refers to a group derived by substituting at least one hydrogen atom in a fluoroalkyl group with a substituent. It should be noted that the examples of the substituted fluoroalkyl group mentioned herein include a group derived by further substituting at least one hydrogen atom bonded to a carbon atom of an alkyl chain of a substituted fluoroalkyl group with a substituent, and a group derived by further substituting at least one hydrogen atom of a substituent of the substituted fluoroalkyl group with a substituent. Specific examples of the unsubstituted fluoroalkyl group include a group derived by substituting at least one hydrogen atom of the alkyl group (specific example group G3) with a fluorine atom.

Substituted or Unsubstituted Haloalkyl Group

[0141] The substituted or unsubstituted haloalkyl group mentioned herein refers to a group derived by substituting at least one hydrogen atom bonded to carbon atoms forming the alkyl group in the substituted or unsubstituted alkyl group with a halogen atom, and also includes a group derived by substituting all hydrogen atoms bonded to carbon atoms forming the alkyl group in the substituted or unsubstituted alkyl group with halogen atoms. An unsubstituted haloalkyl group has, unless otherwise specified herein, 1 to 50, preferably 1 to 30, and more preferably 1 to 18 carbon atoms. The substituted haloalkyl group refers to a group derived by substituting at least one hydrogen atom in a haloalkyl group with a substituent. It should be noted that the examples of the substituted haloalkyl group mentioned herein include a group derived by further substituting at least one hydrogen atom bonded to a carbon atom of an alkyl chain of a substituted haloalkyl group with a substituent, and a group derived by further substituting at least one hydrogen atom of a substituent of the substituted haloalkyl group with a substituent. Specific examples of the unsubstituted haloalkyl group include a group derived by substituting at least one hydrogen atom of the alkyl group (specific example group G3) with a halogen atom. The haloalkyl group is sometimes referred to as a halogenated alkyl group.

Substituted or Unsubstituted Alkoxy Group

[0142] Specific examples of a substituted or unsubstituted alkoxy group mentioned herein include a group represented by O(G3), G3 being the substituted or unsubstituted alkyl group in the specific example group G3. An unsubstituted alkoxy group has, unless otherwise specified herein, 1 to 50, preferably 1 to 30, more preferably 1 to 18 carbon atoms.

Substituted or Unsubstituted Alkylthio Group

[0143] Specific examples of a substituted or unsubstituted alkylthio group mentioned herein include a group represented by S(G3), G3 being the substituted or unsubstituted alkyl group in the specific example group G3. An unsubstituted alkylthio group has, unless otherwise specified herein, 1 to 50, preferably 1 to 30, more preferably 1 to 18 carbon atoms.

Substituted or Unsubstituted Aryloxy Group

[0144] Specific examples of a substituted or unsubstituted aryloxy group mentioned herein include a group represented by O(G1), G1 being the substituted or unsubstituted aryl group in the specific example group G1. An unsubstituted aryloxy group has, unless otherwise specified herein, 6 to 50, preferably 6 to 30, more preferably 6 to 18 ring carbon atoms.

Substituted or Unsubstituted Arylthio Group

[0145] Specific examples of a substituted or unsubstituted arylthio group mentioned herein include a group represented by S(G1), G1 being the substituted or unsubstituted aryl group in the specific example group G1. An unsubstituted arylthio group has, unless otherwise specified herein, 6 to 50, preferably 6 to 30, more preferably 6 to 18 ring carbon atoms.

Substituted or Unsubstituted Trialkylsilyl Group

[0146] Specific examples of a substituted or unsubstituted trialkylsilyl group mentioned herein include a group represented by Si(G3)(G3)(G3), G3 being the substituted or unsubstituted alkyl group in the specific example group G3. A plurality of G3 in Si(G3)(G3)(G3) are mutually the same or different. Each of the alkyl groups in the unsubstituted trialkylsilyl group has, unless otherwise specified herein, 1 to 50, preferably 1 to 20, more preferably 1 to 6 carbon atoms.

Substituted or Unsubstituted Aralkyl Group

[0147] Specific examples of a substituted or unsubstituted aralkyl group mentioned herein include a group represented by -(G3)-(G1), G3 being the substituted or unsubstituted alkyl group in the specific example group G3, G1 being the substituted or unsubstituted aryl group in the specific example group G1. Accordingly, the aralkyl group is a group derived by substituting a hydrogen atom of the alkyl group with a substituent in a form of the aryl group, which is an example of the substituted alkyl group. An unsubstituted aralkyl group, which is an unsubstituted alkyl group substituted by an unsubstituted aryl group, has, unless otherwise specified herein, 7 to 50 carbon atoms, preferably 7 to 30 carbon atoms, more preferably 7 to 18 carbon atoms.

[0148] Specific examples of the substituted or unsubstituted aralkyl group include a benzyl group, 1-phenylethyl group, 2-phenylethyl group, 1-phenylisopropyl group, 2-phenylisopropyl group, phenyl-t-butyl group, a-naphthylmethyl group, 1--naphthylethyl group, 2--naphthylethyl group, 1--naphthylisopropyl group, 2--naphthylisopropyl group, -naphthylmethyl group, 1--naphthylethyl group, 2--naphthylethyl group, 1--naphthylisopropyl group, and 2--naphthylisopropyl group. Preferable examples of the substituted or unsubstituted aryl group mentioned herein include, unless otherwise specified herein, a phenyl group, p-biphenyl group, m-biphenyl group, o-biphenyl group, p-terphenyl-4-yl group, p-terphenyl-3-yl group, p-terphenyl-2-yl group, m-terphenyl-4-yl group, m-terphenyl-3-yl group, m-terphenyl-2-yl group, o-terphenyl-4-yl group, o-terphenyl-3-yl group, o-terphenyl-2-yl group, 1-naphthyl group, 2-naphthyl group, anthryl group, phenanthryl group, pyrenyl group, chrysenyl group, triphenylenyl group, fluorenyl group, 9,9-spirobifluorenyl group, 9,9-dimethylfluorenyl group, and 9,9-diphenylfluorenyl group.

[0149] Preferable examples of the substituted or unsubstituted heterocyclic group mentioned herein include, unless otherwise specified herein, a pyridyl group, pyrimidinyl group, triazinyl group, quinolyl group, isoquinolyl group, quinazolinyl group, benzimidazolyl group, phenanthrolinyl group, carbazolyl group (1-carbazolyl group, 2-carbazolyl group, 3-carbazolyl group, 4-carbazolyl group, or 9-carbazolyl group), benzocarbazolyl group, azacarbazolyl group, diazacarbazolyl group, dibenzofuranyl group, naphthobenzofuranyl group, azadibenzofuranyl group, diazadibenzofuranyl group, dibenzothiophenyl group, naphthobenzothiophenyl group, azadibenzothiophenyl group, diazadibenzothiophenyl group, (9-phenyl) carbazolyl group ((9-phenyl) carbazole-1-yl group, (9-phenyl) carbazole-2-yl group, (9-phenyl) carbazole-3-yl group, or (9-phenyl) carbazole-4-yl group), (9-biphenylyl) carbazolyl group, (9-phenyl)phenylcarbazolyl group, diphenylcarbazole-9-yl group, phenylcarbazole-9-yl group, phenyltriazinyl group, biphenylyltriazinyl group, diphenyltriazinyl group, phenyldibenzofuranyl group, and phenyldibenzothiophenyl group.

[0150] The carbazolyl group mentioned herein is, unless otherwise specified herein, specifically a group represented by one of formulae below.

##STR00012##

[0151] The (9-phenyl) carbazolyl group mentioned herein is, unless otherwise specified herein, specifically a group represented by one of formulae below.

##STR00013##

[0152] In the formulae (TEMP-Cz1) to (TEMP-Cz9), * represents a bonding position.

[0153] The dibenzofuranyl group and dibenzothiophenyl group mentioned herein are, unless otherwise specified herein, each specifically represented by one of formulae below.

##STR00014##

[0154] In the formulae (TEMP-34) to (TEMP-41), each * represents a bonding position.

[0155] Preferable examples of the substituted or unsubstituted alkyl group mentioned herein include, unless otherwise specified herein, a methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, isobutyl group, and t-butyl group.

Substituted or Unsubstituted Arylene Group

[0156] The substituted or unsubstituted arylene group mentioned herein is, unless otherwise specified herein, a divalent group derived by removing one hydrogen atom on an aryl ring of the substituted or unsubstituted aryl group. Specific examples of the substituted or unsubstituted arylene group (specific example group G12) include a divalent group derived by removing one hydrogen atom on an aryl ring of the substituted or unsubstituted aryl group in the specific example group G1.

Substituted or Unsubstituted Divalent Heterocyclic Group

[0157] The substituted or unsubstituted divalent heterocyclic group mentioned herein is, unless otherwise specified herein, a divalent group derived by removing one hydrogen atom on a heterocyclic ring of the substituted or unsubstituted heterocyclic group. Specific examples of the substituted or unsubstituted divalent heterocyclic group (specific example group G13) include a divalent group derived by removing one hydrogen atom on a heterocyclic ring of the substituted or unsubstituted heterocyclic group in the specific example group G2.

Substituted or Unsubstituted Alkylene Group

[0158] The substituted or unsubstituted alkylene group mentioned herein is, unless otherwise specified herein, a divalent group derived by removing one hydrogen atom on an alkyl chain of the substituted or unsubstituted alkyl group. Specific examples of the substituted or unsubstituted alkylene group (specific example group G14) include a divalent group derived by removing one hydrogen atom on an alkyl chain of the substituted or unsubstituted alkyl group in the specific example group G3.

[0159] The substituted or unsubstituted arylene group mentioned herein is, unless otherwise specified herein, preferably any one of groups represented by formulae (TEMP-42) to (TEMP-68) below.

##STR00015## ##STR00016##

[0160] In the formulae (TEMP-42) to (TEMP-52), Q.sub.1 to Q.sub.10 are each independently a hydrogen atom or a substituent.

[0161] In the formulae (TEMP-42) to (TEMP-52), each * represents a bonding position.

##STR00017## ##STR00018##

[0162] In the formulae (TEMP-53) to (TEMP-62), Q.sub.1 to Q.sub.10 are each independently a hydrogen atom or a substituent.

[0163] In the formulae, Q.sub.9 and Q.sub.10 may be mutually bonded through a single bond to form a ring.

[0164] In the formulae (TEMP-53) to (TEMP-62), each * represents a bonding position.

##STR00019##

[0165] In the formulae (TEMP-63) to (TEMP-68), Q.sub.1 to Q.sub.8 are each independently a hydrogen atom or a substituent.

[0166] In the formulae (TEMP-63) to (TEMP-68), each * represents a bonding position.

[0167] The substituted or unsubstituted divalent heterocyclic group mentioned herein is, unless otherwise specified herein, preferably a group represented by any one of formulae (TEMP-69) to (TEMP-102) below.

##STR00020## ##STR00021## ##STR00022##

[0168] In the formulae (TEMP-69) to (TEMP-82), Q.sub.1 to Q.sub.9 are each independently a hydrogen atom or a substituent. In the formulae (TEMP-69) to (TEMP-82), each * represents a bonding position.

##STR00023## ##STR00024## ##STR00025##

[0169] In the formulae (TEMP-83) to (TEMP-102), Q.sub.1 to Q.sub.8 are each independently a hydrogen atom or a substituent. In the formulae (TEMP-83) to (TEMP-102), each * represents a bonding position.

[0170] The substituent mentioned herein has been described above.

Instance of Bonded to Form Ring

[0171] Instances where at least one combination of adjacent two or more (of . . . ) are mutually bonded to form a substituted or unsubstituted monocyclic ring, mutually bonded to form a substituted or unsubstituted fused ring, or not mutually bonded mentioned herein refer to instances where at least one combination of adjacent two or more (of . . . ) are mutually bonded to form a substituted or unsubstituted monocyclic ring, at least one combination of adjacent two or more (of . . . ) are mutually bonded to form a substituted or unsubstituted fused ring, and at least one combination of adjacent two or more (of . . . ) are not mutually bonded.

[0172] Instances where at least one combination of adjacent two or more (of . . . ) are mutually bonded to form a substituted or unsubstituted monocyclic ring and at least one combination of adjacent two or more (of . . . ) are mutually bonded to form a substituted or unsubstituted fused ring mentioned herein (these instances will be sometimes collectively referred to as an instance of bonded to form a ring hereinafter) will be described below.

[0173] An anthracene compound having a basic skeleton in a form of an anthracene ring and represented by a formula (TEMP-103) below will be used as an example for the description.

##STR00026##

[0174] For instance, when at least one combination of adjacent two or more of R.sub.921 to R.sub.930 are mutually bonded to form a ring, the combination of adjacent ones of R.sub.921 to R.sub.930 (i.e. the combination at issue) is a combination of R.sub.921 and R.sub.922, a combination of R.sub.922 and R.sub.923, a combination of R.sub.923 and R.sub.924, a combination of R.sub.924 and R.sub.930, a combination of R.sub.930 and R.sub.925, a combination of R.sub.925 and R.sub.926, a combination of R.sub.926 and R.sub.927, a combination of R.sub.927 and R.sub.928, a combination of R.sub.928 and R.sub.929, or a combination of R.sub.929 and R.sub.921.

[0175] The term at least one combination means that two or more of the above combinations of adjacent two or more of R.sub.921 to R.sub.930 may simultaneously form rings. For instance, when R.sub.921 and R.sub.922 are mutually bonded to form a ring Q.sub.A and R.sub.925 and R.sub.926 are simultaneously mutually bonded to form a ring Q.sub.B, the anthracene compound represented by the formula (TEMP-103) is represented by a formula (TEMP-104) below.

##STR00027##

[0176] The instance where the combination of adjacent two or more form a ring means not only an instance where the two adjacent components are bonded but also an instance where adjacent three or more are bonded. For instance, R.sub.921 and R.sub.922 are mutually bonded to form a ring Q.sub.A and R.sub.922 and R.sub.923 are mutually bonded to form a ring Q.sub.C, and mutually adjacent three components (R.sub.921, R.sub.922 and R.sub.923) are mutually bonded to form a ring fused to the anthracene basic skeleton. In this case, the anthracene compound represented by the formula (TEMP-103) is represented by a formula (TEMP-105) below. In the formula (TEMP-105) below, the ring Q.sub.A and the ring Q.sub.C share R.sub.922.

##STR00028##

[0177] The formed monocyclic ring or fused ring may be, in terms of the formed ring in itself, a saturated ring or an unsaturated ring. When the combination of adjacent two form a monocyclic ring or a fused ring, the monocyclic ring or fused ring may be a saturated ring or an unsaturated ring. For instance, the ring Q.sub.A and the ring Q.sub.B formed in the formula (TEMP-104) are each independently a monocyclic ring or a fused ring. Further, the ring Q.sub.A and the ring Q.sub.C formed in the formula (TEMP-105) are each a fused ring. The ring Q.sub.A and the ring Q.sub.C in the formula (TEMP-105) are fused to form a fused ring. When the ring Q.sub.A in the formula (TEMP-104) is a benzene ring, the ring Q.sub.A is a monocyclic ring. When the ring Q.sub.A in the formula (TEMP-104) is a naphthalene ring, the ring Q.sub.A is a fused ring.

[0178] The unsaturated ring is at least one ring selected from the group consisting of an aromatic hydrocarbon ring, aromatic heterocyclic ring, aliphatic hydrocarbon ring having an unsaturated bond in a cyclic structure, and non-aromatic heterocyclic ring having an unsaturated bond in a cyclic structure. The unsaturated bond in the cyclic structure of the unsaturated ring is one or both of a double bond and a triple bond. The aliphatic hydrocarbon ring having the unsaturated bond in the cyclic structure is exemplified by cyclohexane and cyclohexadiene. The non-aromatic heterocyclic ring having the unsaturated bond in the cyclic structure is exemplified by dihydropyran, imidazoline, pyrazoline, quinolizine, indoline, and isoindoline.

[0179] The saturated ring is at least one ring selected from the group consisting of an aliphatic hydrocarbon ring having no unsaturated bond, and non-aromatic heterocyclic ring having no unsaturated bond. The saturated bond has none of a double bond and a triple bond in its cyclic structure.

[0180] Specific examples of the aromatic hydrocarbon ring include a ring formed by terminating a bond of a group in the specific examples of the specific example group G1 with a hydrogen atom.

[0181] Specific examples of the aromatic heterocyclic ring include a ring formed by terminating a bond of an aromatic heterocyclic group in the specific examples of the specific example group G2 with a hydrogen atom.

[0182] Specific examples of the aliphatic hydrocarbon ring include a ring formed by terminating a bond of a group in the specific examples of the specific example group G6 with a hydrogen atom.

[0183] The phrase to form a ring herein means that a ring is formed only by a plurality of atoms of a basic skeleton, or by a combination of a plurality of atoms of the basic skeleton and one or more optional atoms. For instance, a ring Q.sub.A formed by mutually bonding R.sub.921 and R.sub.922 shown in the formula (TEMP-104) is a ring formed by a carbon atom of an anthracene skeleton bonded to R.sub.921, a carbon atom of an anthracene skeleton bonded to R.sub.922, and one or more optional atoms. Specifically, when the ring Q.sub.A is a monocyclic unsaturated ring formed by R.sub.921 and R.sub.922, the ring formed by a carbon atom of the anthracene skeleton bonded to R.sub.921, a carbon atom of the anthracene skeleton bonded to R.sub.922, and four carbon atoms is a benzene ring.

[0184] The optional atom is, unless otherwise specified herein, preferably at least one atom selected from the group consisting of a carbon atom, nitrogen atom, oxygen atom, and sulfur atom. A bond of the optional atom (e.g. a carbon atom and a nitrogen atom) not forming a ring may be terminated by a hydrogen atom or the like or may be substituted by an optional substituent described later. When the ring includes an optional atom other than a carbon atom, the resultant ring is a heterocyclic ring.

[0185] The number of one or more optional atoms forming the monocyclic ring or fused ring is, unless otherwise specified herein, preferably in a range from 2 to 15, more preferably in a range from 3 to 12, further preferably in a range from 3 to 5.

[0186] Unless otherwise specified herein, the ring, which may be a monocyclic ring or fused ring, is preferably a monocyclic ring.

[0187] Unless otherwise specified herein, the ring, which may be a saturated ring or unsaturated ring, is preferably an unsaturated ring.

[0188] Unless otherwise specified herein, the monocyclic ring is preferably a benzene ring.

[0189] Unless otherwise specified herein, the unsaturated ring is preferably a benzene ring.

[0190] When at least one combination of adjacent two or more (of . . . ) are mutually bonded to form a substituted or unsubstituted monocyclic ring or mutually bonded to form a substituted or unsubstituted fused ring, unless otherwise specified herein, at least one combination of adjacent two or more of components are preferably mutually bonded to form a substituted or unsubstituted unsaturated ring formed of a plurality of atoms of the basic skeleton, and 1 to 15 atoms of at least one atom selected from the group consisting of a carbon atom, a nitrogen atom, an oxygen atom, and a sulfur atom.

[0191] When the monocyclic ring or the fused ring has a substituent, the substituent is the substituent described in later-described optional substituent. When the monocyclic ring or the fused ring has a substituent, specific examples of the substituent are the substituents described in the above under the subtitle

Substituent Mentioned Herein.

[0192] When the saturated ring or the unsaturated ring has a substituent, the substituent is the substituent described in later-described optional substituent. When the saturated ring or the unsaturated ring has a substituent, specific examples of the substituent are the substituents described in the above under the subtitle Substituent Mentioned Herein.

[0193] The above is the description for the instances where at least one combination of adjacent two or more (of . . . ) are mutually bonded to form a substituted or unsubstituted monocyclic ring and at least one combination of adjacent two or more (of . . . ) are mutually bonded to form a substituted or unsubstituted fused ring mentioned herein (sometimes referred to as an instance of bonded to form a ring).

Substituent for Substituted or Unsubstituted Group

[0194] In an exemplary embodiment herein, the substituent for the substituted or unsubstituted group (sometimes referred to as an optional substituent hereinafter), is for instance, a group selected from the group consisting of an unsubstituted alkyl group having 1 to 50 carbon atoms, an unsubstituted alkenyl group having 2 to 50 carbon atoms, an unsubstituted alkynyl group having 2 to 50 carbon atoms, an unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, Si(R.sub.901)(R.sub.902)(R.sub.903), O(R.sub.904), S(R.sub.905), N(R.sub.906)(R.sub.907), a halogen atom, a cyano group, a nitro group, an unsubstituted aryl group having 6 to 50 ring carbon atoms, and an unsubstituted heterocyclic group having 5 to 50 ring atoms; [0195] R.sub.901 to R.sub.907 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms; [0196] when two or more R.sub.901 are present, the two or more R.sub.901 are mutually the same or different; [0197] when two or more R.sub.902 are present, the two or more R.sub.902 are mutually the same or different; [0198] when two or more R.sub.903 are present, the two or more Roos are mutually the same or different; [0199] when two or more R.sub.904 are present, the two or more R.sub.904 are mutually the same or different; [0200] when two or more R.sub.905 are present, the two or more R.sub.905 are mutually the same or different; [0201] when two or more R.sub.906 are present, the two or more R.sub.906 are mutually the same or different; and [0202] when two or more R.sub.907 are present, the two or more R.sub.907 are mutually the same or different.

[0203] In an exemplary embodiment, the substituent for the substituted or unsubstituted group is a group selected from the group consisting of an alkyl group having 1 to 50 carbon atoms, an aryl group having 6 to 50 ring carbon atoms, and a heterocyclic group having 5 to 50 ring atoms.

[0204] In an exemplary embodiment, the substituent for the substituted or unsubstituted group is a group selected from the group consisting of an alkyl group having 1 to 18 carbon atoms, an aryl group having 6 to 18 ring carbon atoms, and a heterocyclic group having 5 to 18 ring atoms.

[0205] Specific examples of the above optional substituent are the same as the specific examples of the substituent described in the above under the subtitle Substituent Mentioned Herein.

[0206] Unless otherwise specified herein, adjacent ones of the optional substituents may form a saturated ring or an unsaturated ring, preferably a substituted or unsubstituted saturated five-membered ring, a substituted or unsubstituted saturated six-membered ring, a substituted or unsubstituted unsaturated five-membered ring, or a substituted or unsubstituted unsaturated six-membered ring, more preferably a benzene ring.

[0207] Unless otherwise specified herein, the optional substituent may further include a substituent. Examples of the substituent for the optional substituent are the same as the examples of the optional substituent.

[0208] When a plurality of optional substituents are present, the plurality of optional substituents are mutually the same or different.

[0209] Herein, numerical ranges represented by AA to BB represent a range whose lower limit is the value (AA) recited before to and whose upper limit is the value (BB) recited after to.

First Exemplary Embodiment

[0210] An arrangement of an organic EL device according to a first exemplary embodiment of the invention will be described below.

[0211] The organic EL device includes an anode, a cathode, and an organic layer between the anode and the cathode. The organic layer includes at least one layer formed from an organic compound(s). Alternatively, the organic layer includes a plurality of layers layered and formed from an organic compound(s). The organic layer may further contain an inorganic compound(s). In the organic EL device of the exemplary embodiment, at least one layer of the organic layer is an emitting layer. For instance, the organic layer may be one emitting layer, or may further include a layer(s) usable in the organic EL device. Examples of the layer usable in the organic EL device, which are not particularly limited, include at least one selected from the group consisting of a hole injecting layer, a hole transporting layer, an electron injecting layer, an electron transporting layer, and a blocking layer.

[0212] The organic EL device of the exemplary embodiment includes an emitting layer between an anode and a cathode.

[0213] The organic EL device of the exemplary embodiment includes the anode, the cathode, and the emitting layer provided between the anode and the cathode, in which the emitting layer contains a compound M3 represented by a formula (1-1) or (1-2) below and a delayed fluorescent compound M2, the compound M3 and the compound M2 are mutually different in structure, and a singlet energy S.sub.1(M3) of the compound M3 and a singlet energy S.sub.1(M2) of the compound M2 satisfy a relationship of a numerical formula (Numerical Formula 1) below.

[00002] $\begin{matrix} S_{1} (M 3) > S_{1} (M 2) & (Numerical Formula 1) \end{matrix}$

[0214] The inventors have found that a high-performance organic EL device is achievable by containing both the compound M3 represented by the formula (1-1) or (1-2) (the compound M3 of the exemplary embodiment) and the delayed fluorescent compound M2 in the emitting layer.

[0215] The compound M3 of the exemplary embodiment is a compound in which benzofuranocarbazole or benzothienocarbazole, which supplies an adequate amount of holes to the emitting layer, is bonded to dibenzofuran or dibenzothiophene, which is highly durable, via meta-bonded biphenylene or ortho-bonded biphenylene with a short conjugation length. Since the compound M3 of the exemplary embodiment exhibits a high triplet energy, a triplet energy of the delayed fluorescent compound can be sufficiently trapped.

[0216] According to the exemplary embodiment, a high-performance organic EL device is achievable.

[0217] According to an exemplary arrangement of the exemplary embodiment, an organic EL device emits light with high efficiency.

[0218] According to an exemplary arrangement of the exemplary embodiment, an organic EL device has a longer lifetime.

[0219] FIG. 1 schematically illustrates an exemplary arrangement of an organic EL device according to the exemplary embodiment.

[0220] An organic EL device 1 includes a light-transmissive substrate 2, an anode 3, a cathode 4, and an organic layer 10 provided between the anode 3 and the cathode 4. The organic layer 10 are a hole injecting layer 6, a hole transporting layer 7, an emitting layer 5, an electron transporting layer 8, and an electron injecting layer 9 that are layered on the anode 3 in this order.

[0221] The emitting layer 5 may contain a metal complex.

[0222] The emitting layer 5 preferably does not contain a phosphorescent material (dopant material).

[0223] The emitting layer 5 preferably does not contain a heavy-metal complex and a phosphorescent rare earth metal complex. Examples of the heavy-metal complex herein include iridium complex, osmium complex, and platinum complex.

[0224] The emitting layer 5 also preferably does not contain a metal complex.

[0225] In the organic EL device 1 according to the exemplary embodiment, the emitting layer 5 contains the delayed fluorescent compound M2 and the compound M3 represented by the formula (1-1) or (1-2).

[0226] In this exemplary arrangement, the compound M2 is preferably a dopant material (also referred to as a guest material, emitter or luminescent material), and the compound M3 is preferably a host material (also referred to as a matrix material). The compound M3 may be a delayed fluorescent compound or a compound exhibiting no delayed fluorescence.

[0227] An arrangement of an organic EL device according to the exemplary embodiment will be described in details below. It should be noted that the description of reference numerals are omitted below.

Emitting Layer

Compound M3

[0228] The emitting layer of the exemplary embodiment contains the compound M3 represented by the formula (1-1) or (1-2) below.

[0229] The compound M3 of the exemplary embodiment may be a thermally activated delayed fluorescent compound or a compound exhibiting no thermally activated delayed fluorescence. However, the compound M3 is preferably a compound exhibiting no thermally activated delayed fluorescence.

##STR00029##

[0230] In the formulae (1-1) and (1-2): [0231] A is a group represented by any one of formulae (11A), (11B), (11C), (11D), (11E), and (11F) below; [0232] L.sub.1 and L.sub.2 are each independently a single bond, or a substituted or unsubstituted arylene group having 6 to 50 ring carbon atoms; [0233] Y.sub.1 is an oxygen atom or a sulfur atom; [0234] at least one combination of adjacent two or more of R.sub.21 to R.sub.28 are mutually bonded to form a substituted or unsubstituted monocyclic ring, mutually bonded to form a substituted or unsubstituted fused ring, or not mutually bonded; [0235] R.sub.21 to R.sub.28 forming neither the substituted or unsubstituted monocyclic ring nor the substituted or unsubstituted fused ring, and R.sub.100 are each independently a hydrogen atom, a halogen atom, a cyano group, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms, a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms, a substituted or unsubstituted alkyl halide group having 1 to 30 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 30 ring carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 30 carbon atoms, a substituted or unsubstituted alkylsilyl group having 3 to 30 carbon atoms, a substituted or unsubstituted arylsilyl group having 6 to 60 ring carbon atoms, a substituted or unsubstituted arylphosphoryl group having 6 to 60 ring carbon atoms, a hydroxy group, a substituted or unsubstituted alkoxy group having 1 to 30 carbon atoms, a substituted or unsubstituted aryloxy group having 6 to 30 ring carbon atoms, a group represented by N(Rz).sub.2, a thiol group, a substituted or unsubstituted alkylthio group having 1 to 30 carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 30 ring carbon atoms, a substituted germanium group, a substituted phosphine oxide group, a nitro group, a substituted boryl group, or a substituted or unsubstituted arylthio group having 6 to 30 ring carbon atoms; [0236] Rz is a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms, or a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms; [0237] two Rz in N(Rz).sub.2 are mutually the same or different; [0238] a plurality of R.sub.100 are mutually the same or different; and [0239] each * in the formulae (1-1) and (1-2) represents a bonding position to any one of carbon atoms of a six-membered ring to which R.sub.21 to R.sub.24 are bonded.

##STR00030## ##STR00031##

[0240] In the formulae (11A), (11B), (11C), (11D), (11E), and (11F): [0241] X.sub.1 is an oxygen atom or a sulfur atom; [0242] at least one combination of adjacent two or more of R.sub.11 to R.sub.20 are mutually bonded to form a substituted or unsubstituted monocyclic ring, mutually bonded to form a substituted or unsubstituted fused ring, or not mutually bonded; [0243] R.sub.11 to R.sub.20 forming neither the substituted or unsubstituted monocyclic ring nor the substituted or unsubstituted fused ring each independently represent the same as R.sub.21 to R.sub.28 forming neither the substituted or unsubstituted monocyclic ring nor the substituted or unsubstituted fused ring in the formulae (1-1) and (1-2); and [0244] each * represents a bonding position.

[0245] In the formulae (11A), (11B), (11C), (11D), (11E), and (11F): [0246] when L.sub.1 is a single bond and L.sub.2 is an arylene group, * represents a bonding position with L.sub.2; [0247] when L.sub.1 is an arylene group and L.sub.2 is a single bond, * represents a bonding position with L.sub.1; [0248] when L.sub.1 and L.sub.2 are each an arylene group, * represents a bonding position with L.sub.1; and [0249] when L.sub.1 and L.sub.2 are each a single bond, * represents a bonding position with a carbon atom in a six-membered ring.

[0250] The compound M3 of the exemplary embodiment is preferably a compound represented by the formula (1-1).

[0251] The compound represented by the formula (1-1) as the compound M3 in the exemplary embodiment is represented by a formula (100-1), (100-2), (100-3), or (100-5) below.

##STR00032##

[0252] In the formulae (100-1), (100-2), (100-3), and (100-5), A, L.sub.1, L.sub.2, Y.sub.1, R.sub.21 to R.sub.28, and R.sub.100 each independently represent the same as A, L.sub.1, L.sub.2, Y.sub.1, R.sub.21 to R.sub.28, and R.sub.100 in the formula (1-1).

[0253] The compound represented by the formula (1-2) as the compound M3 in the exemplary embodiment is represented by a formula (100-4A), (100-4B), (100-4C), or (100-4D) below.

##STR00033##

[0254] In the formulae (100-4A), (100-4B), (100-4C), and (100-4D), A, L.sub.1, L.sub.2, Y.sub.1, R.sub.21 to R.sub.28, and R.sub.100 each independently represent the same as A, L.sub.1, L.sub.2, Y.sub.1, R.sub.21 to R.sub.28, and R.sub.100 in the formula (1-2).

[0255] In a compound M3 according to an exemplary embodiment, L.sub.1 and L.sub.2 are each independently a single bond or a substituted or unsubstituted phenylene group.

[0256] In a compound M3 according to an exemplary embodiment, L.sub.1 and L.sub.2 are each a single bond.

[0257] In a compound M3 according to an exemplary embodiment, A is a group represented by the formula (11F).

[0258] In a compound M3 according to an exemplary embodiment, A is a group represented by the formula (11D).

[0259] In a compound M3 according to an exemplary embodiment, X.sub.1 is a sulfur atom.

[0260] In a compound M3 according to an exemplary embodiment, X.sub.1 is an oxygen atom.

[0261] In a compound M3 according to an exemplary embodiment, Y.sub.1 is an oxygen atom.

[0262] In a compound M3 according to an exemplary embodiment, X.sub.1 is a sulfur atom and Y.sub.1 is an oxygen atom. In a compound M3 according to an exemplary embodiment, X.sub.1 and Y.sub.1 are each an oxygen atom.

[0263] In a compound M3 according to an exemplary embodiment, none of combinations of adjacent two or more of R.sub.21 to R.sub.28 are bonded to each other.

[0264] In a compound M3 according to an exemplary embodiment, R.sub.21 to R.sub.28 are each independently a hydrogen atom or a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms (preferably a substituted or unsubstituted phenyl group).

[0265] In a compound M3 according to an exemplary embodiment, R.sub.21 to R.sub.28 are each independently a hydrogen atom, a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted carbazolyl group, or a substituted or unsubstituted dibenzofuranyl group.

[0266] In a compound M3 according to an exemplary embodiment, R.sub.21 to R.sub.28 are each a hydrogen atom.

[0267] In a compound M3 according to an exemplary embodiment, at least one of R.sub.21 to R.sub.28 is a deuterium atom.

[0268] In a compound M3 according to an exemplary embodiment, none of combinations of adjacent two or more of R.sub.11 to R.sub.20 are bonded to each other.

[0269] In a compound M3 according to an exemplary embodiment, R.sub.11 to R.sub.20 are each independently a hydrogen atom or a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms (preferably a substituted or unsubstituted phenyl group).

[0270] In a compound M3 according to an exemplary embodiment, R.sub.11 to R.sub.20 are each independently a hydrogen atom, a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, or a substituted or unsubstituted carbazolyl group.

[0271] In a compound M3 according to an exemplary embodiment, R.sub.11 to R.sub.20 are each a hydrogen atom.

[0272] In a compound M3 according to an exemplary embodiment, at least one of R.sub.11 to R.sub.20 is a deuterium atom.

[0273] In a compound M3 according to an exemplary embodiment, R.sub.100 is each independently a hydrogen atom or a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms (preferably a substituted or unsubstituted phenyl group).

[0274] In a compound M3 according to an exemplary embodiment, R.sub.100 is each independently a hydrogen atom, a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a trimethylsilyl group.

[0275] In a compound M3 according to an exemplary embodiment, R.sub.100 is a hydrogen atom.

[0276] In a compound M3 according to an exemplary embodiment, at least one of a plurality of R.sub.100 is a deuterium atom.

[0277] In a compound M3 according to an exemplary embodiment, R.sub.100 is not a group represented by N(Rz).sub.2.

[0278] A compound M3 according to an exemplary embodiment is a compound selected from the group consisting of compounds represented by the formulae (100-1) to (100-3) and compounds represented by the formulae (100-4A) to (100-4D). R.sub.100 in the formulae (100-4A) to (100-4D) is preferably not a group represented by N(Rz).sub.2.

[0279] The compounds represented by the formulae (100-1) to (100-3) represent the same as compounds represented by formulae (100-1) to (100-3) among compounds according to a fourth exemplary embodiment.

[0280] The compounds represented by the formulae (100-4A) to (100-4D) in which R.sub.100 is not a group represented by N(Rz).sub.2 represent the same as a compound represented by a formula (100-4) among the compounds according to the fourth exemplary embodiment.

[0281] In an emitting layer according to an exemplary embodiment, only the compound M3 has a larger singlet energy S.sub.1 than the singlet energy S.sub.1(M2) of the delayed fluorescent compound M2.

Producing Method of Compound M3 in the Exemplary Embodiment

[0282] The compound M3 of the exemplary embodiment can be produced, for instance, by a method described in Example described later. The compound M3 of the exemplary embodiment can be produced by application of known substitution reactions and materials depending on a target compound according to reactions described in Example described later.

[0283] Specific examples of the compound M3 in the exemplary embodiment include compounds below. However, the invention is by no means limited to the specific examples of the compound.

##STR00034## ##STR00035## ##STR00036## ##STR00037## ##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## ##STR00078## ##STR00079## ##STR00080## ##STR00081## ##STR00082## ##STR00083## ##STR00084## ##STR00085## ##STR00086## ##STR00087## ##STR00088## ##STR00089## ##STR00090## ##STR00091## ##STR00092## ##STR00093## ##STR00094## ##STR00095## ##STR00096## ##STR00097## ##STR00098## ##STR00099## ##STR00100##

##STR00101## ##STR00102## ##STR00103## ##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## ##STR00130## ##STR00131##

Compound M2

[0284] The emitting layer of the exemplary embodiment contains a delayed fluorescent compound M2.

Delayed Fluorescence

[0285] Delayed fluorescence is explained in Yuki Hando-tai no Debaisu Bussei (Device Physics of Organic Semiconductors) (edited by ADACHI, Chihaya, published by Kodansha, on pages 261-268). This document describes that, if an energy difference E.sub.13 of a fluorescent material between a singlet state and a triplet state is reducible, a reverse energy transfer from the triplet state to the singlet state, which usually occurs at a low transition probability, would occur with high efficiency to express thermally activated delayed fluorescence (TADF). Further, a generation mechanism of delayed fluorescence is explained in FIG. 10.38 in the document. The compound M2 of the exemplary embodiment is preferably a compound exhibiting thermally activated delayed fluorescence generated by such a mechanism.

[0286] In general, emission of delayed fluorescence can be confirmed by measuring the transient PL (Photo Luminescence).

[0287] The behavior of delayed fluorescence can also be analyzed based on the decay curve obtained from the transient PL measurement. The transient PL measurement is a method of irradiating a sample with a pulse laser to excite the sample, and measuring the decay behavior (transient characteristics) of PL emission after the irradiation is stopped. PL emission in TADF materials is classified into a light emission component from a singlet exciton generated by the first PL excitation and a light emission component from a singlet exciton generated via a triplet exciton. The lifetime of the singlet exciton generated by the first PL excitation is on the order of nanoseconds and is very short. Therefore, light emission from the singlet exciton rapidly attenuates after irradiation with the pulse laser.

[0288] On the other hand, the delayed fluorescence is gradually attenuated due to light emission from a singlet exciton generated via a triplet exciton having a long lifetime. As described above, there is a large temporal difference between the light emission from the singlet exciton generated by the first PL excitation and the light emission from the singlet exciton generated via the triplet exciton. Therefore, the luminous intensity derived from delayed fluorescence can be determined.

[0289] FIG. 2 is a schematic diagram of an exemplary apparatus for measuring the transient PL. An example of a method of measuring a transient PL as illustrated in FIG. 2 and an example of behavior analysis of delayed fluorescence will be described.

[0290] A transient PL measuring apparatus 100 in FIG. 2 includes: a pulse laser 101 capable of radiating a light having a predetermined wavelength; a sample chamber 102 configured to house a measurement sample; a spectrometer 103 configured to divide a light radiated from the measurement sample; a streak camera 104 configured to provide a two-dimensional image; and a personal computer 105 configured to import and analyze the two-dimensional image. An apparatus for measuring the transient PL is not limited to the apparatus illustrated in FIG. 2

[0291] The sample housed in the sample chamber 102 is obtained by forming a thin film, in which a matrix material is doped with a doping material at a concentration of 12 mass %, on the quartz substrate.

[0292] The thin film sample housed in the sample chamber 102 is irradiated with the pulse laser from the pulse laser 101 to excite the doping material. Emission is extracted in a direction of 90 degrees with respect to a radiation direction of the excited light. The extracted emission is divided by the spectrometer 103 to form a two-dimensional image in the streak camera 104. As a result, the two-dimensional image is obtainable in which the ordinate axis represents a time, the abscissa axis represents a wavelength, and a bright spot represents a luminous intensity. When this two-dimensional image is taken out at a predetermined time axis, an emission spectrum in which the ordinate axis represents the luminous intensity and the abscissa axis represents the wavelength is obtainable. Moreover, when this two-dimensional image is taken out at the wavelength axis, a decay curve (transient PL) in which the ordinate axis represents a logarithm of the luminous intensity and the abscissa axis represents the time is obtainable.

[0293] For instance, a thin film sample A was prepared as described above from a reference compound H1 as the matrix material and a reference compound D1 as the doping material and was measured in terms of the transient PL.

##STR00132##

[0294] The decay curve was analyzed with respect to the above thin film sample A and a thin film sample B. The thin film sample B was produced in the same manner as described above from a reference compound H2 as the matrix material and the reference compound D1 as the doping material.

[0295] FIG. 3 illustrates decay curves obtained from transient PL obtained by measuring the thin film samples A and B.

##STR00133##

[0296] As described above, an emission decay curve in which the ordinate axis represents the luminous intensity and the abscissa axis represents the time can be obtained by the transient PL measurement. Based on the emission decay curve, a fluorescence intensity ratio between fluorescence emitted from a singlet state generated by photo-excitation and delayed fluorescence emitted from a singlet state generated by reverse energy transfer via a triplet state can be estimated. In a delayed fluorescent material, a ratio of the intensity of the slowly decaying delayed fluorescence to the intensity of the promptly decaying fluorescence is relatively large.

[0297] Specifically, Prompt emission and Delay emission are present as emission from the delayed fluorescent material. Prompt emission is observed promptly when the excited state is achieved by exciting the compound of the exemplary embodiment with a pulse beam (i.e., a beam emitted from a pulse laser) having a wavelength absorbable by the delayed fluorescent material. Delay emission is observed not promptly when the excited state is achieved but after the excited state is achieved.

[0298] An amount of Prompt emission, an amount of Delay emission and a ratio between the amounts thereof can be obtained according to the method as described in Nature 492, 234-238, 2012 (Reference Document 1). The amount of Prompt emission and the amount of Delay emission may be calculated using an apparatus different from one described in Reference Document 1 or one illustrated in FIG. 2.

[0299] Herein, a sample produced by the following method is used for measuring delayed fluorescence of the compound M2. For instance, the compound M2 is dissolved in toluene to prepare a dilute solution with an absorbance of 0.05 or less at the excitation wavelength to eliminate the contribution of self-absorption. In order to prevent quenching due to oxygen, the sample solution is frozen and degassed and then sealed in a cell with a lid under an argon atmosphere to obtain an oxygen-free sample solution saturated with argon.

[0300] The fluorescence spectrum of the sample solution is measured with a spectrofluorometer FP-8600 (produced by JASCO Corporation), and the fluorescence spectrum of a 9,10-diphenylanthracene ethanol solution is measured under the same conditions. Using the fluorescence area intensities of both spectra, the total fluorescence quantum yield is calculated by an equation (1) in Morris et al. J. Phys. Chem. 80 (1976) 969.

[0301] In the exemplary embodiment, provided that an amount of Prompt emission of a measurement target compound (compound M2) is denoted by X.sub.P and an amount of Delay emission is denoted by XD, a value of XD/X.sub.P is preferably 0.05 or more.

[0302] The amounts of Prompt emission and Delay emission and a ratio of the amounts thereof in compounds other than the compound M2 herein are measured in the same manner as those of the compound M2.

Producing Method of Compound M2 in the Exemplary Embodiment

[0303] The compound M2 of the exemplary embodiment can be produced by a known method.

[0304] Specific examples of the compound M2 in the exemplary embodiment include compounds below. However, the invention is by no means limited to these specifically exemplary compounds.

##STR00134## ##STR00135## ##STR00136##

Relationship between Compound M3 and Compound M2 in Emitting Layer

[0305] In the organic EL device according to the exemplary embodiment, a singlet energy S.sub.1(M2) of the compound M2 and a singlet energy S.sub.1(M3) of the compound M3 satisfy a relationship of a numerical formula (Numerical Formula 1) below.

[00003] $\begin{matrix} S_{1} (M 3) > S_{1} (M 2) & (Numerical Formula 1) \end{matrix}$

[0306] An energy gap T.sub.77K (M3) at 77K of the compound M3 is preferably larger than an energy gap T.sub.77K (M2) at 77K of the compound M2. In other words, a relationship of a numerical formula (Numerical Formula 11) below is preferably satisfied.

[00004] $\begin{matrix} T_{7 7 K} (M 3) > T_{7 7 K} (M 2) & (Numerical Formula 11) \end{matrix}$

[0307] When the organic EL device according to the exemplary embodiment emits light, it is preferable that the compound M3 does not mainly emit light in the emitting layer.

Relationship between Triplet Energy and Energy Gap at 77K

[0308] Here, a relationship between a triplet energy and an energy gap at 77K will be described. In the exemplary embodiment, the energy gap at 77K is different from a typically defined triplet energy in some aspects.

[0309] The triplet energy is measured as follows. First, a solution in which a compound (measurement target) is dissolved in an appropriate solvent is encapsulated in a quartz glass tube to prepare a sample. A phosphorescence spectrum (ordinate axis: phosphorescent luminous intensity, abscissa axis: wavelength) of the sample is measured at a low temperature (77K). A tangent is drawn to the rise of the phosphorescence spectrum close to the short-wavelength region. The triplet energy is calculated by a predetermined conversion equation based on a wavelength value at an intersection of the tangent and the abscissa axis.

[0310] Herein, among the compounds of the exemplary embodiment, the thermally activated delayed fluorescent compound is preferably a compound having a small ST. When ST is small, intersystem crossing and inverse intersystem crossing are likely to occur even at a low temperature (77K), so that the singlet state and the triplet state coexist. As a result, the spectrum to be measured in the same manner as the above includes emission from both the singlet state and the triplet state. Although it is difficult to distinguish from which state, the singlet state or the triplet state, light is emitted, the value of the triplet energy is basically considered dominant.

[0311] Accordingly, in the exemplary embodiment, the triplet energy is measured by the same method as a typical triplet energy T, but a value measured in the following manner is referred to as an energy gap T.sub.77K in order to differentiate the measured energy from the typical triplet energy in a strict meaning. The measurement target compound is dissolved in EPA (diethylether: isopentane: ethanol=5:5:2 in volume ratio) at a concentration of 10 mol/L, and the obtained solution is put in a quartz cell to provide a measurement sample. A phosphorescence spectrum (ordinate axis: phosphorescent luminous intensity, abscissa axis: wavelength) of the sample is measured at a low temperature (77K). A tangent is drawn to the rise of the phosphorescence spectrum close to the short-wavelength region. An energy amount is calculated by a conversion equation (F1) below based on a wavelength value .sub.edge [nm] at an intersection of the tangent and the abscissa axis and is defined as an energy gap T.sub.77K at 77K.

[00005] $\begin{matrix} T_{7 7 K} [eV] = 1 2 3 9 .85 /_{e d g e} & Conversion Equation (F1) \end{matrix}$

[0312] The tangent to the rise of the phosphorescence spectrum close to the short-wavelength region is drawn as follows. While moving on a curve of the phosphorescence spectrum from the short-wavelength region to the local maximum value closest to the short-wavelength region among the local maximum values of the phosphorescence spectrum, a tangent is checked at each point on the curve toward the long-wavelength of the phosphorescence spectrum. An inclination of the tangent is increased along the rise of the curve (i.e., a value of the ordinate axis is increased). A tangent drawn at a point of the local maximum inclination (i.e., a tangent at an inflection point) is defined as the tangent to the rise of the phosphorescence spectrum close to the short-wavelength region.

[0313] A local maximum point where a peak intensity is 15% or less of the maximum peak intensity of the spectrum is not counted as the above-mentioned local maximum peak intensity closest to the short-wavelength region. The tangent drawn at a point that is closest to the local maximum peak intensity closest to the short-wavelength region and where the inclination of the curve is the local maximum is defined as a tangent to the rise of the phosphorescence spectrum close to the short-wavelength region.

[0314] For phosphorescence measurement, a spectrophotofluorometer body F-4500 (produced by Hitachi High-Technologies Corporation) is usable. The measurement apparatus is not limited thereto. A combination of a cooling unit, a low temperature container, an excitation light source and a light-receiving unit may be used for measurement.

Singlet Energy S.SUB.1

[0315] A method of measuring a singlet energy S.sub.1 with use of a solution (occasionally referred to as a solution method) is exemplified by a method below.

[0316] A toluene solution of a measurement target compound at a concentration of 10 mol/L is prepared and put in a quartz cell. An absorption spectrum (ordinate axis: absorption intensity, abscissa axis: wavelength.) of the thus-obtained sample is measured at a normal temperature (300K). A tangent is drawn to the fall of the absorption spectrum close to the long-wavelength region, and a wavelength value .sub.edge (nm) at an intersection of the tangent and the abscissa axis is assigned to a conversion equation (F2) below to calculate singlet energy.

[00006] $\begin{matrix} S_{1} [eV] = 1 2 3 9 .85 /_{e d g e} & Conversion Equation (F2) \end{matrix}$

[0317] Any apparatus for measuring absorption spectrum is usable. For instance, a spectrophotometer U3310 manufactured by Hitachi, Ltd. is usable.

[0318] The tangent to the fall of the absorption spectrum close to the long-wavelength region is drawn as follows. While moving on a curve of the absorption spectrum from the local maximum value closest to the long-wavelength region, among the local maximum values of the absorption spectrum, in a long-wavelength direction, a tangent at each point on the curve is checked. An inclination of the tangent is decreased and increased in a repeated manner as the curve falls (i.e., a value of the ordinate axis is decreased). A tangent drawn at a point where the inclination of the curve is the local minimum closest to the long-wavelength region (except when absorbance is 0.1 or less) is defined as the tangent to the fall of the absorption spectrum close to the long-wavelength region.

[0319] The local maximum absorbance of 0.2 or less is not counted as the above-mentioned local maximum absorbance closest to the long-wavelength region.

[0320] In the exemplary embodiment, a difference (S.sub.1-T.sub.77K) between the singlet energy S.sub.1 and the energy gap T.sub.77K at 77K is defined as ST.

[0321] In the exemplary embodiment, a difference ST (M2) between the singlet energy S.sub.1(M2) of the compound M2 and the energy gap T.sub.77K (M2) at 77K of the compound M2 is preferably less than 0.3 eV, more preferably less than 0.2 eV, still more preferably less than 0.1 eV, and still further more preferably less than 0.01 eV. In other words, ST (M2) preferably satisfies a relationship of one of numerical formulae (Numerical Formula 1A) to (Numerical Formula 1D) below.

[00007] $\begin{matrix} ST (M 2) = S_{1} (M 2) - T_{7 7 K} (M 2) < 0.3 eV & (Numerical Formula 1 A) \end{matrix}$ $\begin{matrix} ST (M 2) = S_{1} (M 2) - T_{7 7 K} (M 2) < 0.2 eV & (Numerical Formula 1 B) \end{matrix}$ $\begin{matrix} ST (M 2) = S_{1} (M 2) - T_{7 7 K} (M 2) < 0.1 eV & (Numerical Formula 1 C) \end{matrix}$ $\begin{matrix} ST (M 2) = S_{1} (M 2) - T_{7 7 K} (M 2) < 0.01 eV & (Numerical Formula 1 D) \end{matrix}$

Film Thickness of Emitting Layer

[0322] The film thickness of the emitting layer of the organic EL device in the exemplary embodiment is preferably in a range from 5 nm to 50 nm, more preferably in a range from 7 nm to 50 nm, and most preferably in a range from 10 nm to 50 nm. When the film thickness of the emitting layer is 5 nm or more, the formation of the emitting layer and the adjustment of the chromaticity are easy. When the film thickness of the emitting layer is 50 nm or less, an increase in the drive voltage is likely to be reduced.

Content Ratios of Compounds in Emitting Layer

[0323] For instance, content ratios of the compound M2 and the compound M3 in the emitting layer preferably fall within ranges shown below.

[0324] The content ratio of the compound M2 is preferably in a range from 10 mass % to 80 mass %, more preferably in a range from 10 mass % to 60 mass %, and still more preferably in a range from 20 mass % to 60 mass %.

[0325] The content ratio of the compound M3 is preferably in a range from 20 mass % to 90 mass %, more preferably in a range from 40 mass % to 90 mass %, and still more preferably in a range from 40 mass % to 80 mass %.

[0326] It should be noted that the emitting layer of the exemplary embodiment may contain a material other than the compound M2 and the compound M3.

[0327] The emitting layer may contain a single type of the compound M2 or may contain two or more types of the compound M2. The emitting layer may contain a single type of the compound M3 or may contain two or more types of the compound M3.

[0328] FIG. 4 illustrates an example of a relationship between energy levels of the compound M3 and the compound M2 in the emitting layer. In FIG. 4, S0 represents a ground state. S.sub.1(M2) represents the lowest singlet state of the compound M2. T1(M2) represents the lowest triplet state of the compound M2. S.sub.1(M3) represents the lowest singlet state of the compound M3. T1(M3) represents the lowest triplet state of the compound M3. As illustrated in FIG. 4, when a compound having a small ST (M2) is used as the compound M2, inverse intersystem crossing from the lowest triplet state T1 to the lowest singlet state S.sub.1 can be caused by heat energy.

[0329] The inverse intersystem crossing caused in the compound M2 enables light emission from the lowest singlet state S.sub.1(M2) of the compound M2 to be observed when the emitting layer does not contain a fluorescent dopant with the lowest singlet state S.sub.1 smaller than the lowest singlet state S.sub.1(M2) of the compound M2. It is inferred that the internal quantum efficiency can be theoretically raised up to 100% also by using delayed fluorescence by the TADF mechanism.

[0330] The organic EL device according to the exemplary embodiment contains the delayed fluorescent compound M2 and the compound M3 having a larger singlet energy than that of the compound M2 (compound M3 represented by the formula (1-1) or (1-2)) in the emitting layer.

[0331] According to the exemplary embodiment, a high-performance organic EL device is achievable.

[0332] According to an exemplary arrangement of the exemplary embodiment, an organic EL device emitting light with high efficiency is achievable.

[0333] According to an exemplary arrangement of the exemplary embodiment, an organic EL device emitting light with a long lifetime is achievable.

[0334] The organic EL device according to the exemplary embodiment is usable in an electronic device such as a display device and a light-emitting unit.

[0335] An arrangement of the organic EL device will be further described below.

Substrate

[0336] The substrate is used as a support for the organic EL device. For instance, glass, quartz, plastics and the like are usable for the substrate. A flexible substrate is also usable. The flexible substrate, which is a bendable substrate, is exemplified by a plastic substrate. Examples of a material for the plastic substrate include polycarbonate, polyarylate, polyethersulfone, polypropylene, polyester, polyvinyl fluoride, polyvinyl chloride, polyimide, and polyethylene naphthalate. Further, an inorganic vapor deposition film is also usable.

Anode

[0337] Metal, an alloy, an electrically conductive compound, a mixture thereof, or the like having a large work function (specifically, 4.0 eV or more) is preferably used as the anode formed on the substrate. Specific examples of the material include indium tin oxide (ITO), indium oxide-tin oxide containing silicon or silicon oxide, indium oxide-zinc oxide, indium oxide containing tungsten oxide and zinc oxide, and graphene. In addition, gold (Au), platinum (Pt), nickel (Ni), tungsten (W), chrome (Cr), molybdenum (Mo), iron (Fe), cobalt (Co), copper (Cu), palladium (Pd), titanium (Ti), and nitrides of a metallic material (e.g., titanium nitride) are usable.

[0338] The material is typically formed into a film by a sputtering method. For instance, the indium oxide-zinc oxide can be formed into a film by the sputtering method using a target in which zinc oxide in a range from 1 mass % to 10 mass % is added to indium oxide. Moreover, for instance, the indium oxide containing tungsten oxide and zinc oxide can be formed by the sputtering method using a target in which tungsten oxide in a range from 0.5 mass % to 5 mass % and zinc oxide in a range from 0.1 mass % to 1 mass % are added to indium oxide. In addition, the anode may be formed by a vacuum deposition method, a coating method, an inkjet method, a spin coating method or the like.

[0339] Among the EL layers formed on the anode, since the hole injecting layer adjacent to the anode is formed of a composite material into which holes are easily injectable irrespective of the work function of the anode, a material usable as an electrode material (e.g., metal, an alloy, an electroconductive compound, a mixture thereof, and the elements belonging to the group 1 or 2 of the periodic table) is also usable for the anode.

[0340] The elements belonging to the group 1 or 2 of the periodic table, which are a material having a small work function, specifically, an alkali metal such as lithium (Li) and cesium (Cs), an alkaline earth metal such as magnesium (Mg), calcium (Ca) and strontium (Sr), an alloy containing the alkali metal and the alkaline earth metal (e.g., MgAg, AILi), a rare earth metal such as europium (Eu) and ytterbium (Yb), and an alloy containing the rare earth metal are usable for the anode. It should be noted that the vacuum deposition method and the sputtering method are usable for forming the anode using the alkali metal, alkaline earth metal and the alloy thereof. Further, when a silver paste is used for the anode, the coating method and the inkjet method are usable.

Cathode

[0341] It is preferable to use metal, an alloy, an electroconductive compound, a mixture thereof, or the like having a small work function (specifically, 3.8 eV or less) for the cathode. Examples of materials for the cathode include elements belonging to the group 1 or 2 of the periodic table, specifically, an alkali metal such as lithium (Li) and cesium (Cs), an alkaline earth metal such as magnesium (Mg), calcium (Ca) and strontium (Sr), an alloy containing the alkali metal and the alkaline earth metal (e.g., MgAg, AILi), a rare earth metal such as europium (Eu) and ytterbium (Yb), and an alloy containing the rare earth metal.

[0342] It should be noted that the vacuum deposition method and the sputtering method are usable for forming the cathode using the alkali metal, alkaline earth metal and the alloy thereof. Further, when a silver paste is used for the cathode, the coating method and the inkjet method are usable.

[0343] By providing the electron injecting layer, various conductive materials such as Al, Ag, ITO, graphene, and indium oxide-tin oxide containing silicon or silicon oxide may be used for forming the cathode regardless of the work function. The conductive materials can be formed into a film using the sputtering method, inkjet method, spin coating method, or the like.

Hole Injecting Layer

[0344] The hole injecting layer is a layer containing a substance exhibiting a high hole injectability. Examples of the substance exhibiting a high hole injectability include molybdenum oxide, titanium oxide, vanadium oxide, rhenium oxide, ruthenium oxide, chrome oxide, zirconium oxide, hafnium oxide, tantalum oxide, silver oxide, tungsten oxide, and manganese oxide.

[0345] In addition, the examples of the highly hole-injectable substance include a low-molecule organic compound, examples of which include: an aromatic amine compound such as 4,4,4-tris(N,N-diphenylamino)triphenylamine (abbreviation: 4,4,4-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine TDATA), (abbreviation: MTDATA), 4,4-bis[N-(4-diphenylaminophenyl)-N-phenylamino]biphenyl (abbreviation: DPAB), 4,4-bis(N-{4-[N-(3-methylphenyl)-N-phenylamino]phenyl}-N-phenylamino) biphenyl (abbreviation: DNTPD), 1,3,5-tris[N-(4-diphenylaminophenyl)-N-phenylamino]benzene (abbreviation: DPA3B), 3-[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA1), 3,6-bis[N-(9-phenylcarbazole-3-yl)-N-phenylamino]-9-phenylcarbazole (abbreviation: PCzPCA2), and 3-[N-(1-naphthyl)-N-(9-phenylcarbazole-3-yl)amino]-9-phenylcarbazole (abbreviation: PCzPCN1); and dipyrazino[2,3-f: 20,30-h]quinoxaline-2,3,6,7,10,11-hexacarbonitrile (HAT-CN).

[0346] In addition, a high polymer compound (e.g., oligomer, dendrimer and polymer) is usable as the substance exhibiting a high hole injectability. Examples of the high-molecule compound include poly(N-vinylcarbazole) (abbreviation: PVK), poly(4-vinyltriphenylamine) (abbreviation: PVTPA), poly[N-(4-{N-[4-(4-diphenylamino)phenyl]phenyl-N-phenylamino}phenyl) methacrylamide] (abbreviation: PTPDMA), and poly[N,N-bis(4-butylphenyl)-N,N-bis(phenyl)benzidine] (abbreviation: Poly-TPD). Moreover, an acid-added high polymer compound such as poly(3,4-ethylenedioxythiophene)/poly(styrene sulfonic acid) (PEDOT/PSS) and polyaniline/poly(styrene sulfonic acid) (PAni/PSS) are also usable.

Hole Transporting Layer

[0347] The hole transporting layer is a layer containing a substance exhibiting a high hole transportability. An aromatic amine compound, carbazole derivative, anthracene derivative and the like are usable for the hole transporting layer. Specific examples of a material for the hole transporting layer include 4,4-bis[N-(1-naphthyl)-N-phenylamino]biphenyl (abbreviation: NPB), N,N-bis(3-methylphenyl)-N, N-diphenyl-[1,1-biphenyl]-4,4-diamine (abbreviation: TPD), 4-phenyl-4-(9-phenylfluorene-9-yl)triphenylamine (abbreviation: BAFLP), 4,4-bis[N-(9,9-dimethylfluorene-2-yl)-N-phenylamino]biphenyl (abbreviation: DFLDPBi), 4,4,4-tris(N,N-diphenylamino)triphenylamine (abbreviation: TDATA), 4,4,4-tris[N-(3-methylphenyl)-N-phenylamino]triphenylamine (abbreviation: MTDATA), and 4,4-bis[N-(spiro-9,9-bifluorene-2-yl)-N-phenylamino]biphenyl (abbreviation: BSPB). The above-described substances mostly have a hole mobility of 10-6 cm.sup.2/(V.s) or more.

[0348] For the hole transporting layer, a carbazole derivative such as CBP, 9-[4-(N-carbazolyl)]phenyl-10-phenylanthracene (CzPA), and 9-phenyl-3-[4-(10-phenyl-9-anthryl)phenyl]-9H-carbazole (PCzPA) and an anthracene derivative such as t-BuDNA, DNA, and DPAnth may be used. A high polymer compound such as poly(N-vinylcarbazole) (abbreviation: PVK) and poly(4-vinyltriphenylamine) (abbreviation: PVTPA) is also usable.

[0349] However, in addition to the above substances, any substance exhibiting a higher hole transportability than an electron transportability may be used. It should be noted that the layer containing the substance exhibiting a high hole transportability may be not only a single layer but also a laminate of two or more layers formed of the above substance(s).

[0350] When the hole transporting layer includes two or more layers, one of the layers with a larger energy gap is preferably provided closer to the emitting layer. Such a material is exemplified by HT-2 used in Examples described later.

Electron Transporting Layer

[0351] The electron transporting layer is a layer containing a highly electron-transporting substance. For the electron transporting layer, 1) a metal complex such as an aluminum complex, beryllium complex, and zinc complex, 2) a hetero aromatic compound such as imidazole derivative, benzimidazole derivative, azine derivative, carbazole derivative, and phenanthroline derivative, and 3) a high polymer compound are usable. Specifically, as a low-molecule organic compound, for instance, a metal complex such as Alq, tris(4-methyl-8-quinolinolato) aluminum (abbreviation: Almq.sub.3), bis(10-hydroxybenzo[h]quinolinato) beryllium (abbreviation: BeBq2), BAlq, Znq, ZnPBO and ZnBTZ is usable. In addition to the metal complex, a heteroaromatic compound such as 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviation: PBD), 1,3-bis[5-(ptert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene (abbreviation: OXD-7), 3-(4-tert-butylphenyl)-4-phenyl-5-(4-biphenylyl)-1,2,4-triazole (abbreviation: TAZ), 3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenylyl)-1,2,4-triazole (abbreviation: p-EtTAZ), bathophenanthroline (abbreviation: BPhen), bathocuproine (abbreviation: BCP), and 4,4-bis(5-methylbenzoxazole-2-yl) stilbene (abbreviation: BzOs) is also usable. In the exemplary embodiment, a benzimidazole compound is suitably usable. The above-described substances mostly have an electron mobility of 10-6 cm.sup.2/Vs or more. It should be noted that any other substance than the above substances may be used for the electron transporting layer as long as the substance exhibits a higher electron transportability than the hole transportability. The electron transporting layer may be a single layer or a laminate of two or more layers formed of the above substance.

[0352] Further, a high polymer compound is usable for the electron transporting layer. For instance, poly[(9,9-dihexylfluorene-2,7-diyl)-co-(pyridine-3,5-diyl)] (abbreviation: PF-Py), and poly[(9,9-dioctylfluorene-2,7-diyl)-co-(2,2-bipyridine-6,6-diyl)] (abbreviation: PF-BPy) are usable.

Electron Injecting Layer

[0353] The electron injecting layer is a layer containing a highly electron-injectable substance. Examples of a material for the electron injecting layer include an alkali metal, alkaline earth metal and a compound thereof, examples of which include lithium (Li), cesium (Cs), calcium (Ca), lithium fluoride (LiF), cesium fluoride (CsF), calcium fluoride (CaF.sub.2), and lithium oxide (LiOx). In addition, the alkali metal, alkaline earth metal or the compound thereof may be added to the substance exhibiting the electron transportability in use. Specifically, for instance, magnesium (Mg) added to Alq may be used. In this case, the electrons can be more efficiently injected from the cathode.

[0354] Alternatively, the electron injecting layer may be provided by a composite material in a form of a mixture of the organic compound and the electron donor. Such a composite material exhibits excellent electron injectability and electron transportability since electrons are generated in the organic compound by the electron donor. In this case, the organic compound is preferably a material excellent in transporting the generated electrons. Specifically, the above examples (e.g., the metal complex and the hetero aromatic compound) of the substance forming the electron transporting layer are usable. As the electron donor, any substance exhibiting electron donating property to the organic compound is usable. Specifically, the electron donor is preferably alkali metal, alkaline earth metal and rare earth metal such as lithium, cesium, magnesium, calcium, erbium and ytterbium. The electron donor is also preferably alkali metal oxide and alkaline earth metal oxide such as lithium oxide, calcium oxide, and barium oxide. Moreover, a Lewis base such as magnesium oxide is also usable. Further, the organic compound such as tetrathiafulvalene (abbreviation: TTF) is also usable.

Layer Formation Method

[0355] A method of forming each layer of the organic EL device in the exemplary embodiment is subject to no limitation except for the above particular description. However, known methods of dry film-forming such as vacuum deposition, sputtering, plasma or ion plating and wet film-forming such as spin coating, dipping, flow coating or ink-jet are applicable.

Film Thickness

[0356] A thickness of each layer of the organic layer in the organic EL device according to the exemplary embodiment is not limited except for the above particular description. In general, the thickness preferably ranges from several nanometers to 1 m because excessively small film thickness is likely to cause defects (e.g. pin holes) and excessively large thickness leads to the necessity of applying high voltage and consequent reduction in efficiency.

Second Exemplary Embodiment

[0357] An arrangement of an organic EL device according to a second exemplary embodiment of the invention will be described below. In the description of the second exemplary embodiment, the same components as those in the first exemplary embodiment are denoted by the same reference signs and names to simplify or omit an explanation of the components. In the second exemplary embodiment, the same materials and compounds as described in the first exemplary embodiment are usable, unless otherwise specified.

[0358] The organic EL device according to the second exemplary embodiment is different from the organic EL device according to the first exemplary embodiment in that the emitting layer further includes a fluorescent compound M1. The second exemplary embodiment is the same as the first exemplary embodiment in other respects.

[0359] In an exemplary arrangement of the second exemplary embodiment, the emitting layer contains the compound M3 represented by the formula (1-1) or (1-2), the delayed fluorescent compound M2, and the fluorescent compound M1.

[0360] In an exemplary arrangement of the second exemplary embodiment, it is preferable that the compound M1 is a dopant material, the compound M2 is a host material, and the compound M3 is a host material. Occasionally, one of the compound M2 and the compound M3 is referred as a first host material and the other thereof is referred to as a second host material.

Compound M1

[0361] The emitting layer of the exemplary embodiment contains the fluorescent compound M1.

[0362] The compound M1 of the exemplary embodiment is not a phosphorescent metal complex. The compound M1 of the exemplary embodiment is preferably not a heavy-metal complex. The compound M1 of the exemplary embodiment is preferably not a metal complex.

[0363] The compound M1 of the exemplary embodiment is preferably a compound not exhibiting thermally activated delayed fluorescence.

[0364] A fluorescent material is usable as the compound M1 of the exemplary embodiment. Specific examples of the fluorescent material include a bisarylaminonaphthalene derivative, aryl-substituted naphthalene derivative, bisarylaminoanthracene derivative, aryl-substituted anthracene derivative, bisarylaminopyrene derivative, aryl-substituted pyrene derivative, bisarylamino chrysene derivative, aryl-substituted chrysene derivative, bisarylaminofluoranthene derivative, aryl-substituted fluoranthene derivative, indenoperylene derivative, acenaphthofluoranthene derivative, compound including a boron atom, pyromethene boron complex compound, compound having a pyromethene skeleton, metal complex of the compound having a pyrromethene skeleton, diketopyrrolopyrrole derivative, perylene derivative, and naphthacene derivative.

[0365] When the compound M1 is a fluorescent compound, the compound M1 preferably emits light having a main peak wavelength in a range from 400 nm to 700 nm.

[0366] Herein, the maximum peak wavelength means a peak wavelength of a fluorescence spectrum exhibiting a maximum luminous intensity among fluorescence spectra measured in a toluene solution in which a measurement target compound is dissolved at a concentration ranging from 10-6 mol/l to 10-5 mol/l. A spectrophotofluorometer (F-7000 manufactured by Hitachi High-Tech Science Corporation) is used as a measurement apparatus.

[0367] The compound M1 preferably exhibits red or green light emission.

[0368] Herein, the red light emission refers to light emission whose maximum peak wavelength of fluorescence spectrum is in a range from 600 nm to 660 nm.

[0369] When the compound M1 is a red fluorescent compound, the maximum peak wavelength of the compound M1 is preferably in a range from 600 nm to 660 nm, more preferably in a range from 600 nm to 640 nm, and still more preferably in a range from 610 nm to 630 nm.

[0370] Herein, the green light emission refers to light emission whose maximum peak wavelength of fluorescence spectrum is in a range from 500 nm to 560 nm.

[0371] When the compound M1 is a green fluorescent compound, the maximum peak wavelength of the compound M1 is preferably in a range from 500 nm to 560 nm, more preferably in a range from 500 nm to 540 nm, and still more preferably in a range from 510 nm to 540 nm.

[0372] Herein, the blue light emission refers to light emission whose maximum peak wavelength of fluorescence spectrum is in a range from 430 nm to 480 nm.

[0373] When the compound M1 is a blue fluorescent compound, the maximum peak wavelength of the compound M1 is preferably in a range from 430 nm to 480 nm, more preferably in a range from 440 nm to 480 nm.

[0374] The maximum peak wavelength of the light emitted from the organic EL device is measured as follows.

[0375] Voltage is applied on the organic EL devices such that a current density becomes 10 mA/cm.sup.2, where spectral radiance spectrum is measured by a spectroradiometer CS-2000 (manufactured by Konica Minolta, Inc.).

[0376] A peak wavelength of an emission spectrum, at which the luminous intensity of the resultant spectral radiance spectrum is at the maximum, is measured and defined as the maximum peak wavelength (unit: nm).

Compound Represented by Formula (2A)

[0377] The compound M1 of the exemplary embodiment is preferably a compound represented by a formula (2A) below. The compound M1 preferably emits light having a maximum peak wavelength in a range from 500 nm to 560 nm.

##STR00137##

[0378] In the formula (2A): [0379] a Za ring, a Zb ring, and a Zc ring are each independently a substituted or unsubstituted aromatic hydrocarbon ring having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocycle having 5 to 50 ring atoms; [0380] Ra is bonded to the Za ring or the Zb ring to form a substituted or unsubstituted heterocycle, or not bonded thereto to form no substituted or unsubstituted heterocycle; [0381] Rb is bonded to the Za ring or the Zc ring to form a substituted or unsubstituted heterocycle, or not bonded thereto to form no substituted or unsubstituted heterocycle; and [0382] Ra and Rb not forming the substituted or unsubstituted heterocycling ring are each independently a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.

Compound Represented by Formula (D11)

[0383] The compound M1 of the exemplary embodiment is also preferably a compound represented by a formula (D11) below. A compound represented by the formula (2A) is also preferably a compound represented by a formula (D11) below.

##STR00138## [0384] In the formula (D11): Rb represents the same as Rb in the formula (2A); [0385] X.sub.1 is CR.sub.1 or a nitrogen atom; [0386] X.sub.2 is CR.sub.2 or a nitrogen atom; [0387] X.sub.3 is CR.sub.3 or a nitrogen atom; [0388] X.sub.4 is CR.sub.4 or a nitrogen atom; [0389] X.sub.5 is CR.sub.5 or a nitrogen atom; [0390] X.sub.6 is CR.sub.6 or a nitrogen atom; [0391] X.sub.7 is CR.sub.7, a nitrogen atom, or a carbon atom bonded to X.sub.8 with a single bond; [0392] X.sub.8 is CR.sub.8, a nitrogen atom, or a carbon atom bonded to X.sub.7 with a single bond; [0393] X.sub.9 is CR.sub.9 or a nitrogen atom; [0394] X.sub.10 is CR.sub.10 or a nitrogen atom; [0395] X.sub.11 is CR.sub.11 or a nitrogen atom; [0396] X.sub.12 is CR.sub.12 or a nitrogen atom; [0397] Q is CR.sub.Q or a nitrogen atom; [0398] at least one combination of adjacent two or more of R.sub.1 to R.sub.6 and R.sub.9 to R.sub.11 are mutually bonded to form a substituted or unsubstituted monocyclic ring, mutually bonded to form a substituted or unsubstituted fused ring, or not mutually bonded; [0399] at least one combination of adjacent two or more of R.sub.3, R.sub.4, and Rb are mutually bonded to form a substituted or unsubstituted monocyclic ring, mutually bonded to form a substituted or unsubstituted fused ring, or not mutually bonded; [0400] at least one hydrogen atom in a monocyclic ring or a fused ring formed by mutually bonding at least one combination of adjacent two or more of R.sub.3, R.sub.4, and Rb is substituted or not substituted by at least one substituent selected from the group consisting of an alkyl group having 1 to 50 carbon atoms, an aryl group having 6 to 50 ring carbon atoms, a heterocyclic group having 5 to 50 ring atoms, a group represented by O(R.sub.920), and a group represented by N(R.sub.921)(R.sub.922); at least one hydrogen atom of the substituent is substituted or not substituted by an aryl group having 6 to 50 ring carbon atoms or an alkyl group having 1 to 50 carbon atoms; [0401] R.sub.1 to R.sub.11 forming neither the substituted or unsubstituted monocyclic ring nor the substituted or unsubstituted fused ring, R.sub.12 to R.sub.13, and R.sub.Q are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a group represented by Si(R.sub.911)(R.sub.912)(R.sub.913), a group represented by O(R.sub.914), a group represented by S(R.sub.915), a group represented by N(R.sub.916)(R.sub.917), a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, a group represented by C(O) R.sub.918, a group represented by COOR.sub.919, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms; [0402] Rb forming neither the substituted or unsubstituted monocyclic ring nor the substituted or unsubstituted fused ring is a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms; [0403] R.sub.911 to R.sub.922 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms; [0404] when a plurality of R.sub.911 are present, the plurality of R.sub.911 are mutually the same or different; [0405] when a plurality of R.sub.912 are present, the plurality of R.sub.912 are mutually the same or different; [0406] when a plurality of R.sub.913 are present, the plurality of R.sub.913 are mutually the same or different; [0407] when a plurality of R.sub.914 are present, the plurality of R.sub.914 are mutually the same or different; [0408] when a plurality of R.sub.915 are present, the plurality of R.sub.915 are mutually the same or different; [0409] when a plurality of R.sub.916 are present, the plurality of R.sub.916 are mutually the same or different; [0410] when a plurality of R.sub.917 are present, the plurality of R.sub.917 are mutually the same or different; [0411] when a plurality of R.sub.918 are present, the plurality of R.sub.918 are mutually the same or different; [0412] when a plurality of R.sub.919 are present, the plurality of R.sub.919 are mutually the same or different; [0413] when a plurality of R.sub.920 are present, the plurality of R.sub.920 are mutually the same or different; [0414] when a plurality of R.sub.921 are present, the plurality of R.sub.921 are mutually the same or different; and [0415] when a plurality of R.sub.922 are present, the plurality of R.sub.922 are mutually the same or different.

[0416] The compound represented by the formula (D11) is also preferably represented by a formula (D13) below.

##STR00139##

[0417] In the formula (D13): [0418] R.sub.1 to R.sub.3, R.sub.5 to R.sub.13, and R.sub.Q each independently represent the same as R.sub.1 to R.sub.3, R.sub.5 to R.sub.13, and R.sub.Q in the formula (D11); [0419] at least one combination of adjacent two or more of R.sub.A1 to R.sub.A4 are mutually bonded to form a substituted or unsubstituted monocyclic ring, mutually bonded to form a substituted or unsubstituted fused ring, or not mutually bonded; [0420] R.sub.A1 to R.sub.A4 forming neither the substituted or unsubstituted monocyclic ring nor the substituted or unsubstituted fused ring are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, a group represented by Si(R.sub.931)(R.sub.932)(R.sub.933), a group represented by O(R.sub.934), a group represented by S(R.sub.935), a group represented by N(R.sub.936)(R.sub.937), a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, a group represented by C(O) R.sub.938, a group represented by COOR.sub.939, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms; [0421] R.sub.931 to R.sub.939 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms; [0422] when a plurality of R.sub.931 are present, the plurality of R.sub.931 are mutually the same or different; [0423] when a plurality of R.sub.932 are present, the plurality of R.sub.932 are mutually the same or different; [0424] when a plurality of R.sub.933 are present, the plurality of R.sub.933 are mutually the same or different; [0425] when a plurality of R.sub.934 are present, the plurality of R.sub.934 are mutually the same or different; [0426] when a plurality of R.sub.935 are present, the plurality of R.sub.935 are mutually the same or different; [0427] when a plurality of R.sub.936 are present, the plurality of R.sub.936 are mutually the same or different; [0428] when a plurality of R.sub.937 are present, the plurality of R.sub.937 are mutually the same or different; [0429] when a plurality of R.sub.938 are present, the plurality of R.sub.938 are mutually the same or different; and [0430] when a plurality of R.sub.939 are present, the plurality of R.sub.939 are mutually the same or different.

[0431] The compound represented by the formula (D11) is also preferably represented by a formula (D13A) below.

##STR00140##

[0432] In the formula (D13A): [0433] R.sub.1, R.sub.3, R.sub.5 to R.sub.13, R.sub.Q, and R.sub.A1 to R.sub.A4 each independently represent the same as R.sub.1, R.sub.3, R.sub.5 to R.sub.13, R.sub.Q, and R.sub.A1 to R.sub.A4 in the formula (D13); [0434] at least one combination of adjacent two or more of R.sub.A5 to R.sub.A9 are mutually bonded to form a substituted or unsubstituted monocyclic ring, mutually bonded to form a substituted or unsubstituted fused ring, or not mutually bonded; and [0435] R.sub.A5 to R.sub.A9 forming neither the substituted or unsubstituted monocyclic ring nor the substituted or unsubstituted fused ring each independently represent the same as R.sub.A1 to R.sub.A4 forming neither the substituted or unsubstituted monocyclic ring nor the substituted or unsubstituted fused ring in the formula (D13).

[0436] In the formulae (D13) and (D13A), for instance, a combination of R.sub.5 and R.sub.6 are mutually bonded to form a substituted or unsubstituted monocyclic ring, mutually bonded to form a substituted or unsubstituted fused ring, or not bonded.

[0437] It is also preferable that R.sub.1 to R.sub.13 and R.sub.Q in the compound represented by the formula (D11) are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 5 to 50 ring atoms.

[0438] It is also preferable that R.sub.1 to R.sub.13 and R.sub.Q in the compound represented by the formula (D11) are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 25 carbon atoms, a substituted or unsubstituted aryl group having 6 to 25 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 5 to 25 ring atoms.

[0439] It is also preferable that R.sub.1 to R.sub.3, R.sub.5 to R.sub.13, R.sub.Q, and R.sub.A1 to R.sub.A9 in a compound represented by each of the formulae (D13) and (D13A) are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 5 to 50 ring atoms.

[0440] It is also preferable that R.sub.1 to R.sub.3, R.sub.5 to R.sub.13, R.sub.Q, and R.sub.A1 to R.sub.A9 in a compound represented by each of the formulae (D13) and (D13A) are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 25 carbon atoms, a substituted or unsubstituted aryl group having 6 to 25 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 5 to 25 ring atoms.

[0441] The compound represented by the formula (D11) is also preferably represented by a formula (D14) below.

##STR00141##

[0442] In a compound represented by the formula (D14), R.sub.2, R.sub.6, R.sub.13, R.sub.Q, and R.sub.A2 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted aryl group having 6 to 12 ring carbon atoms, or a substituted or unsubstituted heteroaryl group having 5 to 18 ring atoms.

[0443] It is preferable that R.sub.13 and R.sub.Q in the compound represented by the formula (D14) are each independently a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, a substituted or unsubstituted phenyl group, a substituted or unsubstituted naphthyl group, or a substituted or unsubstituted dibenzofuranyl group.

[0444] In a compound represented by the formula (D14), R.sub.6 and R.sub.A2 are preferably each independently a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 10 atoms.

Compound Represented by Formula (16)

[0445] The compound M1 of the exemplary embodiment is also preferably a compound represented by a formula (16) below. A compound represented by the formula (2A) is also preferably a compound represented by the formula (16) below.

##STR00142##

[0446] In a compound represented by the formula (16): [0447] at least one combination of adjacent two or more of R.sub.161 to R.sub.177 are mutually bonded to form a substituted or unsubstituted monocyclic ring, mutually bonded to form a substituted or unsubstituted fused ring, or not mutually bonded; [0448] R.sub.161 to R.sub.177 forming neither the substituted or unsubstituted monocyclic ring nor the substituted or unsubstituted fused ring are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, a group represented by Si(R.sub.961)(R.sub.962)(R.sub.963), a group represented by O(R.sub.964), a group represented by S(R.sub.965), a group represented by N(R.sub.966)(R.sub.967), a group represented by C(O) R.sub.968, a group represented by COOR.sub.969, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms; [0449] R.sub.961 to R.sub.969 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms; [0450] when a plurality of R.sub.961 are present, the plurality of R.sub.961 are mutually the same or different; [0451] when a plurality of R.sub.962 are present, the plurality of R.sub.962 are mutually the same or different; [0452] when a plurality of R.sub.963 are present, the plurality of R.sub.963 are mutually the same or different; [0453] when a plurality of R.sub.964 are present, the plurality of R.sub.964 are mutually the same or different; [0454] when a plurality of R.sub.965 are present, the plurality of R.sub.965 are mutually the same or different; [0455] when a plurality of R.sub.966 are present, the plurality of R.sub.966 are mutually the same or different; [0456] when a plurality of R.sub.967 are present, the plurality of R.sub.967 are mutually the same or different; [0457] when a plurality of R.sub.968 are present, the plurality of R.sub.968 are mutually the same or different; and [0458] when a plurality of R.sub.969 are present, the plurality of R.sub.969 are mutually the same or different.

[0459] It is preferable that R.sub.161 to R.sub.177 in a compound represented by the formula (16) are each independently a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms, a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms, or a substituted or unsubstituted alkyl group having 1 to 30 carbon atoms.

[0460] In a compound represented by the formula (16), at least one of R.sub.168 to R.sub.170 is preferably a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.

[0461] It is preferable that R.sub.161 to R.sub.177 in a compound represented by the formula (16) are each independently a hydrogen atom, or a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms.

[0462] In a compound represented by the formula (16), R.sub.161 to R.sub.177 are also preferably each a hydrogen atom.

[0463] In a compound represented by the formula (16), it is also preferable that at least one combination of adjacent two or more of R.sub.161 to R.sub.177 are mutually bonded to form a ring represented by a formula (16A) below.

##STR00143##

[0464] In the formula (16A): a dotted line represents a bonding position; and [0465] R.sub.X1 to R.sub.X4 are each independently a hydrogen atom, a substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, a substituted or unsubstituted alkenyl group having 2 to 50 carbon atoms, a substituted or unsubstituted alkynyl group having 2 to 50 carbon atoms, a substituted or unsubstituted cycloalkyl group having 3 to 50 ring carbon atoms, a substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms, a group represented by Si(R.sub.961)(R.sub.962)(R.sub.963), a group represented by O(R.sub.964), a group represented by S(R.sub.965), a group represented by N(R.sub.966)(R.sub.967), a group represented by C(O) R.sub.968, a group represented by COOR.sub.969, a halogen atom, a cyano group, a nitro group, a substituted or unsubstituted aryl group having 6 to 50 ring carbon atoms, or a substituted or unsubstituted heterocyclic group having 5 to 50 ring atoms.

[0466] When a plurality of R.sub.X1 are present, the plurality of R.sub.X1 are mutually the same or different.

[0467] When a plurality of R.sub.X2 are present, the plurality of R.sub.X2 are mutually the same or different.

[0468] When a plurality of R.sub.X3 are present, the plurality of R.sub.X3 are mutually the same or different.

[0469] When a plurality of R.sub.X4 are present, the plurality of R.sub.X4 are mutually the same or different.

[0470] In the formula (16): it is also preferable that at least one of a combination of R.sub.161 and R.sub.162, a combination of R.sub.165 and R.sub.166, a combination of R.sub.172 and R.sub.173, or a combination of R.sub.176 and R.sub.177 are mutually bonded to form a ring represented by the formula (16A).

[0471] In the formula (16), it is preferable that a combination of R.sub.161 and R.sub.162 and a combination of R.sub.176 and R.sub.177 do not form a ring represented by the formula (16A) concurrently.

[0472] In the formula (16), it is also preferable that a combination of R.sub.165 and R.sub.166 are mutually bonded to form a ring represented by the formula (16A) and a combination of R.sub.172 and R.sub.173 are mutually bonded to form a ring represented by the formula (16A). In this arrangement, the compound M1 is represented by a formula (161) below.

[0473] A compound represented by the formula (16) is also preferably a compound represented by a formula (161) below.

##STR00144##

[0474] In the formula (161), R.sub.161 to R.sub.164, R.sub.167 to R.sub.171, R.sub.174 to R.sub.177, and R.sub.X1 to R.sub.X4 each independently represent the same as R.sub.161 to R.sub.164, R.sub.167 to R.sub.171, and R.sub.174 to R.sub.177 in the formula (16) and R.sub.X1 to R.sub.X4 in the formula (16A).

[0475] A compound represented by the formula (16) is also preferably a compound represented by a formula (162) below.

##STR00145##

[0476] In the formula (162): R.sub.161 to R.sub.163, R.sub.168 to R.sub.170, and R.sub.175 to R.sub.177 each independently represent the same as R.sub.161 to R.sub.163, R.sub.168 to R.sub.170, and R.sub.175 to R.sub.177 in the formula (16).

[0477] A compound represented by the formula (16) is also preferably a compound represented by a formula (163) below.

##STR00146##

[0478] In the formula (163), R.sub.162, R.sub.169, and R.sub.176 each independently represent the same as R.sub.162, R.sub.169, and R.sub.176 in the formula (16).

[0479] In the compound M1, the groups specified to be substituted or unsubstituted are each also preferably an unsubstituted group.

Producing Method of Compound M1

[0480] The compound M1 can be produced by a known method.

[0481] Specific examples of the compound M1 in the exemplary embodiment are shown below. However, the invention is by no means limited to these specifically exemplary compounds.

[0482] A coordinate bond between a boron atom and a nitrogen atom in a pyrromethene skeleton is shown by various means such as a solid line, a broken line, an arrow, and omission. Herein, the coordinate bond is shown by a solid line or a broken line, or the description of the coordinate bond is omitted.

##STR00147## ##STR00148## ##STR00149## ##STR00150## ##STR00151## ##STR00152##

##STR00153## ##STR00154## ##STR00155## ##STR00156## ##STR00157## ##STR00158## ##STR00159## ##STR00160## ##STR00161## ##STR00162## ##STR00163## ##STR00164## ##STR00165## ##STR00166## ##STR00167##

##STR00168## ##STR00169## ##STR00170## ##STR00171## ##STR00172##

Relationship between Compound M3, Compound M2 and Compound M1 in Emitting Layer

[0483] In the organic EL device according to the exemplary embodiment, a singlet energy S.sub.1(M1) of the compound M1 and a singlet energy S.sub.1(M2) of the compound M2 satisfy a relationship of a numerical formula (Numerical Formula 2) below.

[00008] $\begin{matrix} S_{1} (M 2) > S_{1} (M 1) & (Numerical Formula 2) \end{matrix}$

[0484] Moreover, the singlet energy S.sub.1(M3) of the compound M3 is preferably larger than the singlet energy S.sub.1(M1) of the compound M1.

[0485] The singlet energy S.sub.1(M3) of the compound M3, the singlet energy S.sub.1(M2) of the compound M2, and the singlet energy S.sub.1(M1) of the compound M1 preferably satisfy a relationship of a numerical formula (Numerical Formula 2A) below.

[00009] $\begin{matrix} S_{1} (M 3) > S_{1} (M 2) > S_{1} (M 1) & (Numerical Formula 2 A) \end{matrix}$

[0486] It is preferable that mainly the fluorescent compound M1 emits light in the emitting layer when the organic EL device of the exemplary embodiment emits light.

[0487] The organic EL device according to the exemplary embodiment preferably emits red light or green light.

Content Ratios of Compounds in Emitting Layer

[0488] Content ratios of the compound M3, the compound M2, and the compound M1 in the emitting layer preferably fall, for instance, within ranges below.

[0489] The content ratio of the compound M3 is preferably in a range from 10 mass % to 80 mass %.

[0490] The content ratio of the compound M2 is preferably in a range from 10 mass % to 80 mass %, more preferably in a range from 10 mass % to 60 mass %, and still more preferably in a range from 20 mass % to 60 mass %.

[0491] The content ratio of the compound M1 is preferably in a range from 0.01 mass % to 10 mass %, more preferably in a range from 0.01 mass % to 5 mass %, and still more preferably in a range from 0.01 mass % to 1 mass %.

[0492] The upper limit of a total of the content ratios of the compound M3, the compound M2, and the compound M1 in the emitting layer is 100 mass %. It should be noted that the emitting layer of the exemplary embodiment may further contain material(s) other than the compounds M3, M2 and M1.

[0493] The emitting layer may contain a single type of the compound M3 or may contain two or more types of the compound M3. The emitting layer may contain a single type of the compound M2 or may contain two or more types of the compound M2. The emitting layer may contain a single type of the compound M1 or may contain two or more types of the compound M1.

[0494] FIG. 5 illustrates an example of a relationship between energy levels of the compound M3, the compound M2, and the compound M1 in the emitting layer. In FIG. 5, S0 represents a ground state. S.sub.1(M1) represents the lowest singlet state of the compound M1. T1(M1) represents the lowest triplet state of the compound M1. S.sub.1(M2) represents the lowest singlet state of the compound M2. T1(M2) represents the lowest triplet state of the compound M2. S.sub.1(M3) represents the lowest singlet state of the compound M3. T1(M3) represents the lowest triplet state of the compound M3. A dashed arrow directed from S.sub.1(M2) to S.sub.1(M1) in FIG. 5 represents Forster energy transfer from the lowest singlet state of the compound M2 to the lowest singlet state of the compound M1.

[0495] As illustrated in FIG. 5, when a compound having a small ST (M2) is used as the compound M2, inverse intersystem crossing from the lowest triplet state T1(M2) to the lowest singlet state S.sub.1(M2) can be caused by a heat energy. Subsequently, Forster energy transfer from the lowest singlet state S.sub.1(M2) of the compound M2 to the compound M1 occurs to generate the lowest singlet state S.sub.1(M1). Consequently, fluorescence from the lowest singlet state S.sub.1(M1) of the compound M1 can be observed. It is inferred that the internal quantum efficiency can be theoretically raised up to 100% also by using delayed fluorescence by the TADF mechanism.

[0496] The organic EL device according to the second exemplary embodiment contains the delayed fluorescent compound M2, the compound M3 having the singlet energy larger than that of the compound M2 (compound M3 represented by the formula (1-1) or (1-2)), and the compound M1 having the singlet energy smaller than that of the delayed fluorescent compound M2 in the emitting layer.

[0497] According to the second exemplary embodiment, a high-performance organic EL device is achievable.

[0498] According to an exemplary arrangement of the second exemplary embodiment, an organic EL device emitting light with high efficiency is achievable.

[0499] According to an exemplary arrangement of the second exemplary embodiment, an organic EL device emitting light with a long lifetime is achievable.

[0500] The organic EL device according to the second exemplary embodiment is usable in an electronic device such as a display device and a light-emitting unit.

Third Exemplary Embodiment

Electronic Device

[0501] An electronic device according to a third exemplary embodiment is installed with any one of the organic EL devices according to the above exemplary embodiments. Examples of the electronic device include a display device and a light-emitting unit. Examples of the display device include a display component (e.g., an organic EL panel module), TV, mobile phone, tablet and personal computer. Examples of the light-emitting unit include an illuminator and a vehicle light.

Fourth Exemplary Embodiment

Compound

[0502] A compound according to a fourth exemplary embodiment is represented by any one of formulae (100-1) to (100-4) below.

[0503] Of the compounds according to the fourth exemplary embodiment, the compounds represented by the formulae (100-1) to (100-3) are in exemplary arrangements of a compound represented by the formula (1-1) described in the first exemplary embodiment, and represent the same as the compounds represented by the formulae (100-1) to (100-3) described in the first exemplary embodiment.

[0504] Of the compounds according to the fourth exemplary embodiment, the compound represented by the formula (100-4) is in an exemplary arrangement of a compound represented by the formula (1-2) described in the first exemplary embodiment, and represents the same as the compounds represented by the formulae (100-4A) to (100-4D) (in which R.sub.100 is not a group represented by N(Rz).sub.2) described in the first exemplary embodiment.

##STR00173##

[0505] In the formulae (100-1) to (100-3), A, L.sub.1, L.sub.2, Y.sub.1, R.sub.21 to R.sub.28, and R.sub.100 each independently represent the same as A, L.sub.1, L.sub.2, Y.sub.1, R.sub.21 to R.sub.28, and R.sub.100 in the formula (1-1).

[0506] In the formula (100-4), A, L.sub.1, L.sub.2, Y.sub.1, R.sub.21 to R.sub.28, and R.sub.100 each independently represent the same as A, L.sub.1, L.sub.2, Y.sub.1, R.sub.21 to R.sub.28, and R.sub.100 in the formula (1-2), with R.sub.100 being not a group represented by N(Rz).sub.2 in the formula (100-4). * in the formula (100-4) represents a bonding position to any one of carbon atoms of a six-membered ring to which R.sub.21 to R.sub.24 are bonded.

[0507] The requirements for L.sub.1, L.sub.2, A, X.sub.1, Y.sub.1, R.sub.21 to R.sub.28, R.sub.11 to R.sub.20, R.sub.100 and the like in the compound M3 according to an exemplary embodiment described above are also applicable as follows to the compound according to the fourth exemplary embodiment.

[0508] The compound according to the fourth exemplary embodiment is preferably a compound represented by the formula (100-1), (100-2), or (100-3).

[0509] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, L.sub.1 and L.sub.2 are each independently a single bond or a substituted or unsubstituted phenylene group.

[0510] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, L.sub.1 and L.sub.2 are each a single bond.

[0511] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, A is a group represented by the formula (11F).

[0512] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, A is a group represented by the formula (11D).

[0513] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, X.sub.1 is a sulfur atom.

[0514] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, X.sub.1 is an oxygen atom.

[0515] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, Y.sub.1 is an oxygen atom.

[0516] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, X.sub.1 is a sulfur atom and Y.sub.1 is an oxygen atom. In an exemplary arrangement of the compound according to the fourth exemplary embodiment, X.sub.1 and Y.sub.1 are each an oxygen atom.

[0517] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, none of combinations of adjacent two or more of R.sub.21 to R.sub.28 are bonded to each other.

[0518] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, R.sub.21 to R.sub.28 are each independently a hydrogen atom or a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms (preferably a substituted or unsubstituted phenyl group).

[0519] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, R.sub.21 to R.sub.28 are each independently a hydrogen atom, a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted carbazolyl group, or a substituted or unsubstituted dibenzofuranyl group.

[0520] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, R.sub.21 to R.sub.28 are each a hydrogen atom.

[0521] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, at least one of R.sub.21 to R.sub.28 is a deuterium atom.

[0522] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, none of combinations of adjacent two or more of R.sub.11 to R.sub.20 are bonded to each other.

[0523] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, R.sub.11 to R.sub.20 are each independently a hydrogen atom or a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms (preferably a substituted or unsubstituted phenyl group).

[0524] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, R.sub.11 to R.sub.20 are each independently a hydrogen atom, a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, or a substituted or unsubstituted carbazolyl group.

[0525] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, R.sub.11 to R.sub.20 are each a hydrogen atom.

[0526] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, at least one of R.sub.11 to R.sub.20 is a deuterium atom.

[0527] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, each R.sub.100 is independently a hydrogen atom or a substituted or unsubstituted aryl group having 6 to 30 ring carbon atoms (preferably a substituted or unsubstituted phenyl group).

[0528] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, each R.sub.100 is independently a hydrogen atom, a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted dibenzofuranyl group, a substituted or unsubstituted carbazolyl group, a substituted or unsubstituted alkyl group having 1 to 6 carbon atoms, or a trimethylsilyl group.

[0529] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, R.sub.100 is a hydrogen atom.

[0530] In an exemplary arrangement of the compound according to the fourth exemplary embodiment, at least one of a plurality of R.sub.100 is a deuterium atom.

[0531] According to the fourth exemplary embodiment, a high-performance organic EL device is achievable.

[0532] According to an exemplary arrangement of the fourth exemplary embodiment, an organic EL device emitting light with high efficiency is achievable. According to an exemplary arrangement of the fourth exemplary embodiment, an organic EL device emitting light with a long lifetime is achievable. The compound according to the fourth exemplary embodiment is usable in an electronic device such as a display device and a light-emitting unit.

Organic EL Device

[0533] An organic EL device according to an exemplary arrangement of the fourth exemplary embodiment contains the compound of the fourth exemplary embodiment (compound represented by any one of the formulae (100-1) to (100-4)) in any layer of the organic layer provided between the anode and the cathode.

[0534] An organic EL device according to an exemplary arrangement of the fourth exemplary embodiment contains the compound represented by the formulae (100-1), (100-2), or (100-3) in any layer of the organic layer provided between the anode and the cathode.

[0535] The compound according to the fourth exemplary embodiment enables an organic EL device to have a high performance. Accordingly, an organic EL device according to an exemplary arrangement of the fourth exemplary embodiment has a high performance. An organic EL device according to an exemplary arrangement of the fourth exemplary embodiment emits light with high efficiency. An organic EL device according to an exemplary arrangement of the fourth exemplary embodiment emits light with a long lifetime.

[0536] Specific examples of the compound according to the fourth exemplary embodiment include the same compounds as those exemplifying the compound M3 in the first exemplary embodiment. However, the invention is by no means limited to these specifically exemplary compounds.

Fifth Exemplary Embodiment

Organic-EL-Device Material

[0537] An organic-EL-device material of a fifth exemplary embodiment contains the compound of the fourth exemplary embodiment.

[0538] According to the organic-EL-device material of the fifth exemplary embodiment, high-performance organic EL device and electronic device are achievable.

[0539] The organic-EL-device material of the sixth exemplary embodiment may further contain an additional compound. When the organic-EL-device material of the sixth exemplary embodiment further contains an additional compound, the additional compound may be solid or liquid.

Modification of Embodiments

[0540] The scope of the invention is not limited by the above exemplary embodiments but includes any modification and improvement as long as such modification and improvement are compatible with the invention.

[0541] For instance, the emitting layer is not limited to a single layer, but may be provided by layering a plurality of emitting layers. When the organic EL device has the plurality of emitting layers, it is only required that at least one of the emitting layers satisfies the conditions described in the above exemplary embodiments. For instance, the rest of the emitting layers may be a fluorescent emitting layer or a phosphorescent emitting layer with use of emission caused by electron transfer from the triplet excited state directly to the ground state.

[0542] In a case where the organic EL device includes a plurality of emitting layers, these emitting layers may be mutually adjacently provided, or may form a so-called tandem organic EL device, in which a plurality of emitting units are layered via an intermediate layer.

[0543] For instance, a blocking layer may be provided adjacent to at least one of a side of the emitting layer close to the anode or a side of the emitting layer close to the cathode. The blocking layer is preferably provided in contact with the emitting layer to block at least one of holes, electrons, or excitons.

[0544] For instance, when the blocking layer is provided in contact with the side of the emitting layer close to the cathode, the blocking layer permits transport of electrons and blocks holes from reaching a layer provided closer to the cathode (e.g., the electron transporting layer) beyond the blocking layer. When the organic EL device includes the electron transporting layer, the blocking layer is preferably interposed between the emitting layer and the electron transporting layer.

[0545] When the blocking layer is provided in contact with the side of the emitting layer close to the anode, the blocking layer permits transport of holes and blocks electrons from reaching a layer provided closer to the anode (e.g., the hole transporting layer) beyond the blocking layer. When the organic EL device includes the hole transporting layer, the blocking layer is preferably interposed between the emitting layer and the hole transporting layer.

[0546] Alternatively, the blocking layer may be provided adjacent to the emitting layer so that the excitation energy does not leak out from the emitting layer toward neighboring layer(s). The blocking layer blocks excitons generated in the emitting layer from being transferred to a layer(s) (e.g., the electron transporting layer and the hole transporting layer) closer to the electrode(s) beyond the blocking layer. The emitting layer is preferably bonded with the blocking layer.

[0547] The specific structure, shape, and the like of the components in the invention may be designed in any manner as long as an object of the invention can be achieved.

EXAMPLES

[0548] The invention will be described in further detail with reference to Examples. The scope of the invention is by no means limited to Examples.

Compounds

[0549] The compound M3 represented by the formula (1-1), which was used for producing organic EL devices in Examples, is shown below.

##STR00174##

[0550] A compound used for producing an organic EL device in Comparative is shown below.

##STR00175##

[0551] Other compounds used for producing organic EL devices in Examples and Comparative are shown below.

##STR00176## ##STR00177##

[0552] Production of Organic EL Device

Example 1

[0553] A glass substrate (size: 25 mm75 mm1.1 mm thick, produced by Geomatec Co., Ltd.) having an ITO transparent electrode (anode) was ultrasonic-cleaned in isopropyl alcohol for five minutes, and then UV-ozone-cleaned for one minute. The film thickness of ITO was 130 nm.

[0554] After the glass substrate having the transparent electrode line was cleaned, the glass substrate was mounted on a substrate holder of a vacuum deposition apparatus. Firstly, a compound HT-1 and a compound HA were co-deposited on a surface of the glass substrate where the transparent electrode line was provided in a manner to cover the transparent electrode, thereby forming a 10-nm-thick hole injecting layer. Concentrations of the compound HT-1 and the compound HA in the hole injecting layer were 97 mass % and 3 mass %, respectively.

[0555] The compound HT-1 was then vapor-deposited on the hole injecting layer to form a 90-nm-thick hole transporting layer.

[0556] A compound HT-2 was then vapor-deposited on the hole transporting layer to form a 30-nm-thick electron blocking layer.

[0557] Next, a fluorescent compound GD-1 as the compound M1, a delayed fluorescent compound TADF-1 as the compound M2, and a compound M3-1 as the compound M3 were co-deposited on the electron blocking layer to form a 40-nm-thick emitting layer. Concentrations of the compound GD-1, the compound TADF-1, and the compound M3-1 in the emitting layer were 0.6 mass %, 25 mass %, and 74.4 mass %, respectively.

[0558] Next, a compound ET-1 was vapor-deposited on the emitting layer to form a 5-nm-thick hole blocking layer.

[0559] Next, a compound ET-2 and a compound Liq were co-deposited on the hole blocking layer to form a 35-nm-thick electron transporting layer. Concentrations of the compound ET-2 and the compound Liq in the electron transporting layer were 50 mass % and 50 mass %, respectively. Liq is an abbreviation of (8-quinolinolato) lithium ((8-Quinolinolato) lithium).

[0560] Next, ytterbium (Yb) was vapor-deposited on the electron transporting layer to form a 1-nm-thick electron injectable electrode (cathode).

[0561] Subsequently, metal aluminum (Al) was vapor-deposited on the electron injectable electrode to form an 80-nm-thick metal Al cathode.

[0562] A device arrangement of the organic EL device in Example 1 is roughly shown as follows. [0563] ITO (130)/HT-1: HA (10,97%: 3%)/HT-1 (90)/HT-2 (30)/M3-1: TADF-1: GD-1 (40,74.4%: 25%: 0.6%)/ET-1 (5)/ET-2: Liq (35,50%: 50%)/Yb (1)/AI (80)

Numerals in Parentheses Represent a Film Thickness (Unit: Nm).

[0564] The numerals (97%: 3%) represented by percentage in the same parentheses indicate a ratio (mass %) between the compound HT-1 and the compound HA in the hole injecting layer. The numerals (74.4%: 25%: 0.6%) represented by percentage in the same parentheses indicate a ratio (mass %) between the compound M3, the compound M2, and the compound M1 in the emitting layer. The numerals (50%: 50%) represented by percentage in the same parentheses indicate a ratio (mass %) between the compound ET-2 and the compound Liq in the electron transporting layer.

Examples 2 and 3

[0565] The organic EL devices in Examples 2 and 3 were produced in the same manner as in Example 1 except that the compound M3-1 used in Example 1 was replaced by respective compounds shown in Table 1.

Comparative 1

[0566] An organic EL device in Comparative 1 was produced in the same manner as in Example 1 except that the compound M3-1 used in Example 1 was replaced by a compound shown in Table 1.

Example 4

[0567] An organic EL device in Example 4 was produced in the same manner as in Example 1 except that the concentration of the compound TADF-1 in the emitting layer of Example 1 was changed to the concentration shown in Table 1 and the concentration of the compound M3-1 in the emitting layer of Example 1 was changed to 69.4 mass % (wt %).

Examples 5 and 6

[0568] The organic EL devices in Examples 5 and 6 were produced in the same manner as in Example 4 except that the compound M3-1 used in Example 4 was replaced by respective compounds shown in Table 1.

Comparative 2

[0569] An organic EL device in Comparative 2 was produced in the same manner as in Example 4 except that the compound M3-1 used in Example 4 was replaced by a compound shown in Table 1.

Evaluation on Organic EL Devices

[0570] The produced organic EL devices were evaluated as follows. Table 1 shows measurement results.

External Quantum Efficiency EQE

[0571] Voltage was applied to the organic EL devices such that a current density was 10 mA/cm.sup.2, where spectral radiance spectrum was measured with a spectroradiometer CS-2000 (produced by Konica Minolta, Inc.). The external quantum efficiency EQE (unit: %) was calculated based on the obtained spectral radiance spectra, assuming that the spectra was provided under a Lambertian radiation. Table 1 shows EQE (relative value) (unit: %).

[0572] EQE (relative value) in each of Examples 1 to 3 was calculated based on the measurement value of EQE and according to a numerical formula (Numerical Formula 1X) below.

[0573] EQE (relative value) in each of Examples 4 to 6 was calculated based on the measurement value of EQE and according to a numerical formula (Numerical Formula 2X) below.

[00010] $\begin{matrix} EQE (relative value) = (EQE of each Example / EQE of Comparative 1) 100 & (Numerical Formula 1 X) \end{matrix}$ $\begin{matrix} EQE (relative value) = (EQE of each Example / EQE of Comparative 2) 100 & (Numerical Formula 2 X) \end{matrix}$

Maximum Peak Wavelength Ap

[0574] Voltage was applied to the organic EL devices such that a current density was 10 mA/cm.sup.2, where spectral radiance spectrum was measured with a spectroradiometer CS-2000 (produced by Konica Minolta, Inc.). The maximum peak wavelength Ap (unit: nm) was calculated from the obtained spectral radiance spectrum.

Lifetime LT95

[0575] Voltage was applied to the organic EL device produced in each Example so that a current density was 50 mA/cm.sup.2, where a time (LT95 (unit: hr)) elapsed before a luminance intensity was reduced to 95% of the initial luminance intensity was measured. The luminance intensity was measured with a spectroradiometer CS-2000 (manufactured by Konica Minolta, Inc.). Table 1 shows LT95 (relative value) (unit: %).

[0576] LT95 (relative value) in each of Examples 1 to 3 was calculated based on the measurement value of LT95 and according to a numerical formula (Numerical Formula 1Y) below.

[0577] LT95 (relative value) in each of Examples 4 to 6 was calculated based on the measurement value of LT95 and according to a numerical formula (Numerical Formula 2Y) below.

[00011] $\begin{matrix} LT 95 (relative value) = (LT 95 of each Example / LT 95 of Comparative 1) 100 & (Numerical Formula 1 Y) \end{matrix}$ $\begin{matrix} LT 95 (relative value) = (LT 95 of each Example / LT 95 of Comparative 2) 100 & (Numerical Formula 2 Y) \end{matrix}$

CIE1931 Chromaticity

[0578] Voltage was applied to each organic EL device so that a current density of the organic EL device was 10 mA/cm.sup.2, where coordinates of CIE1931 chromaticity (x, y) were measured by a spectroradiometer CS-2000 (produced by Konica Minolta, Inc.).

TABLE-US-00001 TABLE 1 Device Evaluation Results Compound M2 EQE LT95 Compound M3 Concen- Compound M1 (relative (relative S.sub.1 T.sub.77K tration S.sub.1 ST S.sub.1 .sub.p value) value) Name [eV] [eV] Name [wt %] [eV] [eV] Name [eV] [nm] CIE x CIE y [nm] [%] [h] Ex. 1 M3-1 3.36 2.85 TADF-1 25 2.61 <0.01 GD-1 2.39 512 0.270 0.667 520 109 125 Ex. 2 M3-2 3.46 2.93 TADF-1 25 2.61 <0.01 GD-1 2.39 512 0.266 0.670 519 107 89 Ex. 3 M3-3 3.46 2.89 TADF-1 25 2.61 <0.01 GD-1 2.39 512 0.262 0.671 519 104 141 Comp. 1 Ref-1 3.41 2.72 TADF-1 25 2.61 <0.01 GD-1 2.39 512 0.263 0.673 519 100 100 Ex. 4 M3-1 3.36 2.85 TADF-1 30 2.61 <0.01 GD-1 2.39 512 0.274 0.667 520 114 122 Ex. 5 M3-2 3.46 2.93 TADF-1 30 2.61 <0.01 GD-1 2.39 512 0.271 0.668 520 114 102 Ex. 6 M3-3 3.46 2.89 TADF-1 30 2.61 <0.01 GD-1 2.39 512 0.266 0.670 519 108 132 Comp. 2 Ref-1 3.41 2.72 TADF-1 30 2.61 <0.01 GD-1 2.39 512 0.269 0.670 519 100 100

[0579] The organic EL devices of Examples 1 to 3, which contained the compound M3 represented by the formula (1-1), the delayed fluorescent compound M2, and the fluorescent compound M1 in the emitting layer, emitted light with higher efficiency than the organic EL device of Comparative 1 having the compound Ref-1 in place of the compound M3.

[0580] Moreover, the organic EL devices of Examples 4 to 6, which contained the compound M3 represented by the formula (1-1), the delayed fluorescent compound M2, and the fluorescent compound M1 in the emitting layer, emitted light with higher efficiency and had a longer lifetime than the organic EL device of Comparative 2 having the compound Ref-1 in place of the compound M3.

Evaluation on Compounds

[0581] Physical property values of compounds listed in Table 1 were measured according to the following methods.

Delayed Fluorescence of Compound TADF-1

[0582] Delayed fluorescence was checked by measuring transient PL using an apparatus illustrated in FIG. 2. The compound TADF-1 was dissolved in toluene to prepare a dilute solution with an absorbance of 0.05 or less at the excitation wavelength to eliminate contribution of self-absorption. In order to prevent quenching due to oxygen, the sample solution was frozen and degassed and then sealed in a cell with a lid under an argon atmosphere to obtain an oxygen-free sample solution saturated with argon.

[0583] The fluorescence spectrum of the sample solution was measured with a spectrofluorometer FP-8600 (produced by JASCO Corporation), and the fluorescence spectrum of a 9,10-diphenylanthracene ethanol solution was measured under the same conditions. Using the fluorescence area intensities of both spectra, the total fluorescence quantum yield was calculated by an equation (1) in Morris et al. J. Phys. Chem. 80 (1976) 969.

[0584] Prompt emission was observed immediately when the excited state was achieved by exciting the compound TADF-1 with a pulse beam (i.e., a beam emitted from a pulse laser) having a wavelength to be absorbed by the compound TADF-1, and Delay emission was observed not immediately when the excited state was achieved but after the excited state was achieved. The delayed fluorescence in Examples means that an amount of Delay emission is 5% or more relative to an amount of Prompt emission. Specifically, provided that the amount of Prompt emission is denoted by X.sub.P and the amount of Delay emission is denoted by XD, the delayed fluorescence means that a value of XD/X.sub.P is 0.05 or more.

[0585] An amount of Prompt emission, an amount of Delay emission and a ratio between the amounts thereof can be obtained according to the method as described in Nature 492, 234-238, 2012 (Reference Document 1). The amount of Prompt emission and the amount of Delay emission may be calculated using an apparatus different from one described in Reference Document 1 or one illustrated in FIG. 2.

[0586] It was confirmed that the amount of Delay emission was 5% or more with respect to the amount of Prompt emission in the compound TADF-1.

[0587] Specifically, the value of XD/X.sub.P was 0.05 or more with respect to the compound TADF-1.

Singlet Energy S.SUB.1

[0588] A singlet energy S.sub.1 of each of measurement target compounds was measured according to the above-described solution method.

Energy Gap T.SUB.77K .at 77K

[0589] T.sub.77K of each of the measurement target compounds was measured according to the measurement method of the energy gap T.sub.77K described in the above Relationship between Triplet Energy and Energy Gap at 77K. ST was checked from the measurement results of T.sub.77K and the above values of the singlet energy S.sub.1. [0590] ST of the compound GD-1 was 0.40 eV.

Maximum Peak Wavelength of Compounds

[0591] A maximum peak wavelength of each compound was measured as follows.

[0592] A toluene solution of each measurement target compound at a concentration of 5 mol/L was prepared and put in a quartz cell. An emission spectrum (ordinate axis: luminous intensity, abscissa axis: wavelength) of the thus-obtained sample was measured at a normal temperature (300K). In Examples, the emission spectrum was measured using a spectrophotometer manufactured by Hitachi, Ltd. (device name: F-7000). It should be noted that the machine for measuring the emission spectrum is not limited to the machine used herein. A peak wavelength of the emission spectrum exhibiting the maximum luminous intensity was defined as the maximum peak wavelength .

Synthesis of Compounds

[0593] Compounds M3-1 to M3-3 were synthesized.

Synthesis Example 1: Synthesis of Compound M3-1

[0594] (1-1) Synthesis of Intermediate M-1

##STR00178##

[0595] Under a nitrogen atmosphere, dimethoxyethane (150 mL) and water (30 mL) were added to a mixture of 3-chlorophenylboronic acid (4.63 g, 29.6 mmol), 2-(3-bromophenyl)dibenzo[b,d]furan (9.56 g, 29.6 mmol), bis(triphenylphosphine) palladium (II) dichloride (0.623 g, 0.888 mmol), and sodium carbonate (4.71 g, 44.4 mmol), and the obtained mixture was stirred at 90 degrees C. for three hours. After completion of the reaction, water and toluene were added to the reaction solution, and the organic layer was extracted therefrom and washed with saturated saline solution. The organic layer was dried over sodium sulfate and filtrated. Subsequently, the solvent was distilled away. The obtained reaction product was purified by silica gel chromatography to obtain an intermediate M-1 (8.71 g, a yield of 83%). The obtained product was identified as the intermediate M-1 by analysis according to LC-MS (Liquid Chromatography-Mass spectrometry).

[0596] (1-2) Synthesis of Compound M3-1

##STR00179##

[0597] Under a nitrogen atmosphere, xylene (30 mL) was added to a mixture of 12H-benzo[4,5]thieno[2,3-]carbazole (1.70 g, 6.21 mmol), intermediate M-1 (2.10 g, 5.91 mmol), dibenzylideneacetone palladium (0.68 g, 0.118 mmol), 2-dicyclohexylphosphino-2,4,6-triisopropylbiphenyl (0.113 g, 0.236 mmol), and sodium tert-butoxide (0.852 g, 8.87 mmol), and the obtained mixture was stirred at 140 degrees C. for two hours. After completion of the reaction, water and toluene were added to the reaction solution, and the organic layer was extracted therefrom and washed with saturated saline solution. The organic layer was dried over sodium sulfate and filtrated. Subsequently, the solvent was distilled away. The obtained reaction product was purified by silica gel chromatography and recrystallized using toluene to obtain a compound M3-1 (0.85 g, a yield of 24%). The obtained compound was identified as the compound M3-1 by analysis according to LC-MS.

Synthesis Example 2: Synthesis of Compound M3-2

(2-1) Synthesis of Compound M3-2

##STR00180##

[0598] Under a nitrogen atmosphere, xylene (30 mL) was added to a mixture of 5H-benzofuro[3,2-c]carbazole (1.64 g, 6.38 mmol), intermediate M-1 (2.16 g, 6.08 mmol), dibenzylideneacetone palladium (0.699 g, 0.122 mmol), 2-dicyclohexylphosphino-2,4,6-triisopropylbiphenyl (0.116 g, 0.243 mmol), and sodium tert-butoxide (0.877 g, 9.12 mmol), and the obtained mixture was stirred at 140 degrees C. for two hours. After completion of the reaction, water and toluene were added to the reaction solution, and the organic layer was extracted therefrom and washed with saturated saline solution. The organic layer was dried over sodium sulfate and filtrated. Subsequently, the solvent was distilled away. To the obtained reaction product was added heptane, followed by filtration, and the filtrate was recrystallized using toluene to obtain a compound M3-2 (0.92 g, a yield of 26%). The obtained compound was identified as the compound M3-2 by analysis according to LC-MS.

Synthesis Example 3: Synthesis of Compound M3-3

(3-1) Synthesis of Compound M3-3

##STR00181##

[0599] Under a nitrogen atmosphere, xylene (30 mL) was added to a mixture of 12H-benzofuro[2,3-]carbazole (1.64 g, 6.38 mmol), intermediate M-1 (2.16 g, 6.08 mmol), dibenzylideneacetone palladium (0.699 g, 0.122 mmol), 2-dicyclohexylphosphino-2,4,6-triisopropylbiphenyl (0.116 g, 0.243 mmol), and sodium tert-butoxide (0.877 g, 9.12 mmol), and the obtained mixture was stirred at 140 degrees C. for two hours. After the reaction, a solid was filtrated, washed with methanol, and recrystallized with toluene to obtain a compound M3-3 (2.45 g, a yield of 70%). The obtained compound was identified as the compound M3-3 by analysis according to LC-MS.

EXPLANATION OF CODES

[0600] 1 . . . organic EL device, 2 . . . substrate, 3 . . . anode, 4 . . . cathode, 5 . . . emitting layer, 6 . . . hole injecting layer, 7 . . . hole transporting layer, 8 . . . electron transporting layer, 9 . . . electron injecting layer

ORGANIC ELECTROLUMINESCENT ELEMENT, COMPOUND, AND ELECTRONIC DEVICE

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Abstract

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