Composition, light-emitting element, and polymer compound and low molecular weight compound

Abstract

To provide a composition useful for producing a light-emitting device having excellent external quantum efficiency, a light-emitting device containing the composition, and a polymer compound and a low-molecular-weight compound that can be contained in the composition.SOLUTION: A composition contains at least two compounds selected from the group consisting of a polymer compound (B), a polymer compound (H), a low molecular weight compound (h), a hole-transporting low molecular weight compound, a hole-injecting low molecular weight compound, an electron-transporting low molecular weight compound, an electron-injecting low molecular weight compound, and a light-emitting low molecular weight compound, and at least one of the at least two compounds is the polymer compound (B), and each compound satisfies specific requirements.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a composition, a light-emitting device, a polymer compound, and a low-molecular-weight compound. [Background technology]

[0002] Light-emitting devices such as organic electroluminescent devices can be suitably used for displays and lighting applications. As light-emitting materials used in the light-emitting layer of light-emitting devices, for example, Patent Document 1 describes a composition containing a polymer compound including a structural unit derived from Compound BM1 and Compound HM1. Patent Document 2 describes a composition containing a polymer compound including a structural unit derived from Compound BCMO and Compound HM2.

[0003] [ka] [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-13757 [Patent Document 2] Japanese Patent Publication No. 2022-24744 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the external quantum efficiency of the light-emitting device fabricated using the above composition is not necessarily sufficient. Therefore, an object of the present invention is to provide a composition useful for producing a light-emitting device having excellent external quantum efficiency, a light-emitting device containing the composition, and a polymer compound and a low-molecular-weight compound that can be contained in the composition. [Means for solving the problem]

[0006] The present invention provides the following [1] to

[15] .

[0007] [1] Polymer compounds (B), polymer compounds (H), low molecular weight compounds (h), hole transporting low molecular weight compounds, hole injecting low molecular weight compounds, electron transporting low molecular weight compounds, electron injecting low molecular weight compounds a composition containing at least two compounds selected from the group consisting of a luminescent compound and a luminescent low molecular weight compound, At least one compound among the at least two compounds is the polymer compound (B), The polymer compound (B) contains a boron atom, a nitrogen atom, an oxygen atom, a sulfur atom, a selenium atom, and sp 3 a polymer compound comprising a structural unit (b) having a group formed by removing one or more hydrogen atoms from a low molecular weight compound (b) having a heterocyclic skeleton (b) in which six or more rings are fused, the heterocyclic skeleton containing, in the fused ring, at least one selected from the group consisting of carbon atoms; the polymer compound (H) is a polymer compound that does not contain the structural unit (b), The low molecular weight compound (h) has sp 3 A low molecular weight compound having a polycyclic aromatic hydrocarbon ring skeleton containing carbon atoms, or having sp 3 It is a low molecular weight compound having a polycyclic heterocyclic skeleton containing carbon atoms, The hole transporting low molecular weight compound, the hole injecting low molecular weight compound, the electron transporting low molecular weight compound, the electron injecting low molecular weight compound, and the light emitting low molecular weight compound each have an isopropyl group in the ring. 3 A polycyclic aromatic hydrocarbon ring skeleton containing carbon atoms and sp 3 It is a low molecular weight compound that does not contain a polycyclic heterocyclic skeleton containing carbon atoms, The composition, wherein when the composition does not contain the polymer compound (H) and the low molecular weight compound (h), the low molecular weight compound (b) satisfies at least one of the requirements (i) and (ii). (i) The nitrogen atom, the oxygen atom, the sulfur atom, the selenium atom, and the sp atom contained in the fused ring of the heterocyclic skeleton (b)3 The total number of carbon atoms is 4 or more. (ii) The number of nitrogen atoms contained in the fused ring of the heterocyclic skeleton (b) is 2 or more.

[0008] [2] The composition according to [1], wherein the polymer compound (B) is a polymer compound containing a structural unit having a group in which one or more hydrogen atoms have been removed from a low molecular weight compound (b) having a heterocyclic skeleton (b) that satisfies the requirement (i).

[0009] [3] The composition according to [1] or [2], wherein the heterocyclic skeleton (b) is a heterocyclic skeleton represented by formula (b1-1): [ka] [In the formula, Ring R b1 , ring R b2 , ring R b3 , ring R b4 and ring R b5 each independently represents an aromatic hydrocarbon ring or a heterocyclic ring, and these rings may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. X b1 , X b2 , X b3 and X b4 are each independently an oxygen atom, a sulfur atom, a selenium atom, -N(R xb )-, an alkylene group, or a cycloalkylene group, These groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. R xbrepresents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. X b1 and ring R b1 , X b1 and ring R b2 , X b2 and ring R b1 , X b2 and ring R b3 , X b3 and ring R b2 , X b3 and ring R b4 , X b4 and ring R b4 , X b4 and ring R b5 , ring R b2 and ring R b3 , ring R b2 and ring R b5 , and ring R b3 and ring R b5 may each independently bond directly or via a divalent or higher valent group which may have a substituent to form a ring. When a plurality of such substituents are present, they may be the same or different and may bond to each other to form a ring together with the atom to which they are bonded.

[0010] [4] The low molecular weight compound having a heterocyclic skeleton represented by the formula (b1-1) further satisfies the requirement (ii) and b1 , the X b2 , the X b3 and the X b4 At least two of the following are -N(R xb )-, a group represented by [3].

[0011] [5] X b1 , the X b2 , the X b3 and the X b4 each independently represents an oxygen atom, a sulfur atom, or -N(Rxb )-, wherein R 1 is a group represented by the formula (3) or (4).

[0012] [6] The sp 2 contained in the low molecular weight compound having a heterocyclic skeleton represented by the formula (b1-1) 3 The composition according to any one of [3] to [5], wherein the total number of carbon atoms is 9 or more.

[0013] [7] The composition according to any one of [3] to [6], wherein the low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1) has at least one selected from the group consisting of an aryl group having three or more substituents and a monovalent heterocyclic group having three or more substituents.

[0014] [8] The composition according to any one of [1] to [7], wherein the structural unit (b) is a structural unit represented by formula (BP-1), a structural unit represented by formula (BP-2), or a structural unit represented by formula (BP-3). [ka] [In the formula, M BP1 represents a group obtained by removing one hydrogen atom from the low molecular weight compound (b). M BP2 represents a group obtained by removing two hydrogen atoms from the low molecular weight compound (b). M BP3 represents a group obtained by removing three hydrogen atoms from the low molecular weight compound (b). L BP1 represents an alkylene group, a cycloalkylene group, an arylene group, a divalent heterocyclic group, -N(R BP1 )-, an oxygen atom, or a sulfur atom, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. R BP1represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. L BP1 When there are a plurality of groups, they may be the same or different. n BP1 represents an integer between 0 and 10. Ar BP1 represents a hydrocarbon group or a heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded.

[0015] [9] The composition according to any one of [1] to [8], wherein the polymer compound (B) further contains at least one structural unit selected from the group consisting of a structural unit represented by formula (X) and a structural unit represented by formula (Y): [ka] [In the formula, a X1 and a X2 each independently represents an integer of 0 or greater. Ar X1 and Ar X3 each independently represents an arylene group or a divalent heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. Ar X2 and Ar X4are each independently an arylene group, a divalent heterocyclic group, or a divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. Ar X2 When a plurality of Ar are present, they may be the same or different. X4 When there are a plurality of groups, they may be the same or different. R X1 , R X2 and R X3 are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form Each of them may form a ring together with the atom to which it is attached. X2 When there are multiple R's, they may be the same or different. X3 When there are multiple, they may be the same or different. [ka] [In the formula, Ar Y1 represents an arylene group, a divalent heterocyclic group, or a divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded to each other, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded.

[0016]

[10] At least one compound among the at least two compounds is the polymer compound (H), The composition according to any one of [1] to [9], wherein the polymer compound (H) is a polymer compound containing at least one type of structural unit selected from the group consisting of a structural unit represented by formula (X) and a structural unit represented by formula (Y). [ka] [In the formula, a X1 and a X2 each independently represents an integer of 0 or greater. Ar X1 and Ar X3 each independently represents an arylene group or a divalent heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. Ar X2 and Ar X4 are each independently an arylene group, a divalent heterocyclic group, or a divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. Ar X2 When a plurality of Ar are present, they may be the same or different. X4 When there are a plurality of groups, they may be the same or different. R X1 , R X2 and R X3 are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form Each of them may form a ring together with the atom to which it is attached. X2 When there are multiple R's, they may be the same or different. X3 When there are multiple, they may be the same or different. [ka] [In the formula, Ar Y1 represents an arylene group, a divalent heterocyclic group, or a divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded to each other, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded.

[0017]

[11] At least one compound among the at least two compounds is the low molecular weight compound (h), The composition according to any one of [1] to

[10] , wherein the low molecular weight compound (h) is a low molecular weight compound represented by formula (h-1). [ka] [In the formula, n 1h represents an integer greater than or equal to 0. Ar 1h has sp 3 From a polycyclic aromatic hydrocarbon ring containing carbon atoms, a hydrogen atom n directly bonded to an atom constituting the ring 1h or a group excluding sp in the ring 3 From a polycyclic heterocycle containing carbon atoms, a hydrogen atom n directly bonded to an atom constituting the ring 1h These groups may have a substituent. When a plurality of the substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. R 1h represents an aryl group, a monovalent heterocyclic group, or a substituted amino group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. R 1hWhen a plurality of are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. Ar 1h and the substituents that may be present on R 1h may be bonded to each other to form a ring together with the atoms to which they are bonded.

[0018]

[12] The composition according to any one of [1] to

[11] , further comprising at least one selected from the group consisting of an antioxidant and a solvent.

[0019]

[13] A light-emitting device having an anode, a cathode, and an organic layer provided between the anode and the cathode, The organic layer is a light-emitting layer containing the composition according to any one of [1] to

[12] . element.

[0020]

[14] A polymer compound containing a structural unit having a group in which one or more hydrogen atoms have been removed from a low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1'). [ka] [In the formula, Ring R b1 , ring R b2 , ring R b3 , ring R b4 and ring R b5 each independently represents an aromatic hydrocarbon ring or a heterocyclic ring, and these rings may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. X b1 , X b2 , X b3 and X b4 are each independently an oxygen atom, a sulfur atom, a selenium atom, -N(R xb)-, an alkylene group, or a cycloalkylene group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. R xb represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. X b1 and ring R b1 , X b1 and ring R b2 , X b2 and ring R b1 , X b2 and ring R b3 , X b3 and ring R b2 , X b3 and ring R b4 , X b4 and ring R b4 , X b4 and ring R b5 , ring R b2 and ring R b3 , ring R b2 and ring R b5 , and ring R b3 and ring R b5 may each independently bond directly or via a divalent or higher valent group which may have a substituent to form a ring. When a plurality of such substituents are present, they may be the same or different and may bond to each other to form a ring together with the atoms to which they are bonded. However, the sp 3 The total number of carbon atoms is 9 or more, or the low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1') has at least one selected from the group consisting of an aryl group having three or more substituents and a monovalent heterocyclic group having three or more substituents.

[0021]

[15] A low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1'-M): [ka] [In the formula, Ring R b1 , ring R b2 , ring R b3 , ring R b4 and ring R b5 each independently represents an aromatic hydrocarbon ring or a heterocyclic ring, and these rings may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. X b1 , X b2 , X b3 and X b4 are each independently an oxygen atom, a sulfur atom, a selenium atom, -N(R xb )-, an alkylene group, or a cycloalkylene group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. R xb represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. X b1 and ring R b1 , X b1 and ring R b2 , X b2 and ring R b1 , X b2 and ring R b3 , X b3 and ring R b2 , X b3 and ring R b4 , X b4 and ring R b4 , X b4 and ring R b5 , ring R b2and ring R b3 , ring R b2 and ring R b5 , and ring R b3 and ring R b5 may each independently bond directly or via a divalent or higher valent group which may have a substituent to form a ring. When a plurality of such substituents are present, they may be the same or different and may bond to each other to form a ring together with the atoms to which they are bonded. However, the sp 3 In terms of the total number of carbon atoms, the number of R contained in the low molecular weight compound having a heterocyclic skeleton represented by the formula (b1-1'-M) is C1 sp included in 3 The number obtained by subtracting the total number of carbon atoms is 9 or more, or the low molecular weight compound represented by formula (b1-1'-M) has at least one selected from the group consisting of an aryl group having three or more substituents and a monovalent heterocyclic group having three or more substituents. In addition, the low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1'-M) has at least one selected from the group consisting of a chlorine atom, a bromine atom, an iodine atom, -OS(=O)2R C1 a group represented by -B(OR C1 )2, a group represented by -BF3Q', a group represented by -MgY', a group represented by -ZnY', and a group represented by -Sn(R C1 R has at least one selected from the group consisting of groups represented by C1 represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. R C1 When a plurality of are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. Q' represents Li, Na, K, Rb, or Cs. Y' represents a chlorine atom, a bromine atom, or an iodine atom.] [Effects of the Invention]

[0022] According to the present invention, a composition useful for producing a light-emitting device having excellent external quantum efficiency can be provided. Furthermore, according to the present invention, a light-emitting device containing the composition can be provided. Furthermore, according to the present invention, a polymer compound and a low molecular weight compound that can be contained in the composition can be provided. DETAILED DESCRIPTION OF THE INVENTION

[0023] Preferred embodiments of the present invention will be described in detail below.

[0024] <Explanation of common terms> Terms commonly used in this specification have the following meanings unless otherwise specified.

[0025] "Room temperature" means 25°C.

[0026] Me represents a methyl group, Et represents an ethyl group, Bu represents a butyl group, i-Pr represents an isopropyl group, and t-Bu represents a tert-butyl group. The hydrogen atom may be a deuterium atom or a proton atom. In the formula representing a metal complex, the solid line representing a bond to a central metal means an ionic bond, a covalent bond, or a coordinate bond.

[0027] "Low molecular weight compounds" are compounds that do not have a molecular weight distribution and have a molecular weight of 1 x 10 4 The following compounds are meant:

[0028] "Polymer compounds" are compounds that have a molecular weight distribution and have a number average molecular weight of 1 x 10 in terms of polystyrene. 3 or more (e.g., 1×10 3 ~1×10 8 ) means a polymer in which The term "structural unit" refers to a unit that exists in one or more instances in a polymer compound. A structural unit that exists in two or more instances in a polymer compound is generally also called a "repeating unit." The polymer compound may be any of a block copolymer, a random copolymer, an alternating copolymer, a graft copolymer, or other forms. The terminal group of the polymer compound is preferably a stable group from the viewpoint of the light-emitting properties of the light-emitting device. The terminal group of the polymer compound is preferably a group that is conjugated to the main chain of the polymer compound, and examples thereof include an aryl group or a monovalent heterocyclic group that is bonded to the main chain of the polymer compound via a carbon-carbon bond.

[0029] The "alkyl group" may be either linear or branched. The number of carbon atoms in a linear alkyl group, not including the number of carbon atoms in the substituent, is usually 1 to 50, preferably 1 to 20, and more preferably 1 to 10. The number of carbon atoms in a branched alkyl group, not including the number of carbon atoms in the substituent, is usually 3 to 50, preferably 3 to 20, and more preferably 4 to 10.

[0030] The alkyl group may have a substituent. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a 2-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isoamyl group, a 2-ethylbutyl group, a hexyl group, a heptyl group, an octyl group, a 2-ethylhexyl group, a 3-propylheptyl group, a decyl group, a 3,7-dimethyloctyl group, a 2-ethyloctyl group, a 2-hexyldecyl group, and a dodecyl group. The alkyl group may also include groups in which some or all of the hydrogen atoms in these groups have been substituted with a substituent (e.g., a trifluoromethyl group, a pentafluoroethyl group, a perfluorobutyl group, a perfluorohexyl group, a perfluorooctyl group, a 3-phenylpropyl group, a 3-(4-methylphenyl)propyl group, a 3-(3,5-dihexylphenyl)propyl group, and a dodecyl group. propyl group and 6-ethyloxyhexyl group).

[0031] The number of carbon atoms in the "cycloalkyl group" is usually 3 to 50, preferably 3 to 20, and more preferably 4 to 10, not including the number of carbon atoms in the substituent. The cycloalkyl group may have a substituent. Examples of the cycloalkyl group include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, and groups in which some or all of the hydrogen atoms in these groups have been substituted with substituents.

[0032] The number of carbon atoms in the "alkylene group" is usually 1 to 50, preferably 1 to 20, and more preferably 1 to 10, not including the number of carbon atoms in the substituent. The alkylene group may have a substituent. Examples of the alkylene group include a methylene group, an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, and groups in which some or all of the hydrogen atoms in these groups have been substituted with substituents.

[0033] The number of carbon atoms in the "cycloalkylene group" is usually 3 to 50, preferably 4 to 20, and more preferably 5 to 10, not including the number of carbon atoms in the substituent. The cycloalkylene group may have a substituent. Examples of the cycloalkylene group include a cyclopropylene group, a cyclobutylene group, a cyclopentylene group, a cyclohexylene group, a cycloheptylene group, a cyclooctylene group, and groups in which some or all of the hydrogen atoms in the groups have been substituted with substituents.

[0034] An "aromatic hydrocarbon group" refers to a group obtained by removing one or more hydrogen atoms directly bonded to carbon atoms constituting an aromatic hydrocarbon ring. A group obtained by removing one hydrogen atom directly bonded to a carbon atom constituting the ring from an aromatic hydrocarbon ring is also called an "aryl group." A group obtained by removing two hydrogen atoms directly bonded to carbon atoms constituting the ring from an aromatic hydrocarbon ring is also called an "arylene group." The number of carbon atoms in the aromatic hydrocarbon group is usually 6 to 60, preferably 6 to 40, and more preferably 6 to 20, not including the number of carbon atoms in the substituent.

[0035] Examples of the "aromatic hydrocarbon group" include groups in which one or more hydrogen atoms directly bonded to carbon atoms constituting the ring have been removed from a monocyclic aromatic hydrocarbon ring (such as benzene) or a polycyclic aromatic hydrocarbon ring (such as bicyclic aromatic hydrocarbon rings such as naphthalene, indene, naphthoquinone, indenone, and tetralone; tricyclic aromatic hydrocarbon rings such as anthracene, phenanthrene, dihydrophenanthrene, dibenzocycloheptane, fluorene, anthraquinone, phenanthoquinone, and fluorenone; tetracyclic aromatic hydrocarbon rings such as benzanthracene, benzophenanthrene, and benzofluorene; pentacyclic aromatic hydrocarbon rings such as dibenzanthracene, dibenzophenanthrene, dibenzofluorene, indenofluorene, and benzofluoranthene; hexacyclic aromatic hydrocarbon rings such as spirobifluorene; and heptacyclic aromatic hydrocarbon rings such as benzospirobifluorene and acenaphthofluoranthene). The aromatic hydrocarbon group includes a group in which a plurality of these groups are bonded together. The aromatic hydrocarbon group may have a substituent.

[0036] The "alkoxy group" may be either linear or branched. The number of carbon atoms in a linear alkoxy group, not including the number of carbon atoms in the substituent, is usually 1 to 50, preferably 1 to 20, and more preferably 1 to 10. The number of carbon atoms in a branched alkoxy group, not including the number of carbon atoms in the substituent, is usually 3 to 50, preferably 3 to 20, and more preferably 4 to 10. The alkoxy group may have a substituent. Examples of the alkoxy group include methoxy. Examples of such groups include silyl, ethoxy, isopropyloxy, butyloxy, hexyloxy, 2-ethylhexyloxy, 3,7-dimethyloctyloxy, lauryloxy, and groups in which some or all of the hydrogen atoms in these groups have been substituted with substituents.

[0037] The number of carbon atoms in the "cycloalkoxy group" is usually 3 to 50, preferably 3 to 20, and more preferably 4 to 10, not including the number of carbon atoms in the substituent. The cycloalkoxy group may have a substituent. Examples of the cycloalkoxy group include a cyclohexyloxy group and groups in which some or all of the hydrogen atoms in the cycloalkoxy group have been substituted with substituents.

[0038] The number of carbon atoms in the "aryloxy group" is usually 6 to 60, preferably 6 to 40, and more preferably 6 to 20, not including the number of carbon atoms in the substituent. The aryloxy group may have a substituent. Examples of the aryloxy group include a phenoxy group, a naphthyloxy group, an anthracenyloxy group, a pyrenyloxy group, and groups in which some or all of the hydrogen atoms in these groups have been substituted with substituents.

[0039] A "heterocyclic group" refers to a group obtained by removing, from a heterocycle, one or more hydrogen atoms directly bonded to atoms constituting the ring (carbon atoms or heteroatoms). Among heterocyclic groups, an "aromatic heterocyclic group", which is a group obtained by removing, from an aromatic heterocycle, one or more hydrogen atoms directly bonded to atoms constituting the ring, is preferred. A group obtained by removing, from a heterocycle, p hydrogen atoms (p represents an integer of 1 or more) directly bonded to atoms constituting the ring is also called a "p-valent heterocyclic group". A group obtained by removing, from an aromatic heterocycle, p hydrogen atoms directly bonded to atoms constituting the ring is also called a "p-valent aromatic heterocyclic group".

[0040] Examples of the "aromatic heterocycle" include compounds in which the heterocycle itself exhibits aromaticity, such as azole, thiophene, furan, pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, and carbazole, as well as compounds in which an aromatic ring is condensed with a heterocycle, even if the heterocycle itself does not exhibit aromaticity, such as phenoxazine, phenothiazine, and benzopyran.

[0041] The number of carbon atoms in the heterocyclic group, not including the number of carbon atoms in the substituent, is usually 1 to 60, preferably 2 to 40, and more preferably 3 to 20. The number of heteroatoms in the heterocyclic group, not including the number of heteroatoms in the substituent, is usually 1 to 30, preferably 1 to 10, more preferably 1 to 5, and even more preferably 1 to 3.

[0042] Examples of the heterocyclic group include monocyclic heterocycles (e.g., furan, thiophene, oxadiazole, thiadiazole, pyrrole, diazole, triazole, tetrazole, pyridine, diazabenzene, and triazine), and polycyclic heterocycles (e.g., bicyclic heterocycles such as azanaphthalene, diazanaphthalene, benzofuran, benzothiophene, indole, azaindole, diazaindole, benzodiazole, benzothiadiazole, benzotriazole, benzothiophene dioxide, benzothiophene oxide, and benzopyranone; dibenzofuran, dibenzothiophene, dibenzothiophene dioxide, dibenzothiophene oxide, dibenzopyranone, dibenzoborole, dibenzosilole, dibenzophosphole, dibenzoselenophene, carbazole, azacarbazole, diazacarbazole, phenoxazine, phenothiazine, 9,10-dihydroacridine, 5,10-dihydro Tricyclic heterocycles such as phenazine, acridone, phenazaborine, phenophosphazine, phenoselenazine, phenazasiline, azaanthracene, diazaanthracene, azaphenanthrene, and diazaphenanthrene; tetracyclic heterocycles such as hexaazatriphenylene, benzocarbazole, azabenzocarbazole, diazabenzocarbazole, benzonaphthofuran, and benzonaphthothiophene; dibenzocarbazole, indolocarbazole, indenocarbazole, Examples of heterocyclic groups include 5-ring heterocycles such as carbazolocarbazole, azaindolocarbazole, diazaindenocarbazole, and diazaindenocarbazole; 6-ring heterocycles such as carbazolocarbazole, benzoindolocarbazole, and benzoindenocarbazole; and 7-ring heterocycles such as dibenzoindolocarbazole and dibenzoindenocarbazole. Examples of heterocyclic groups include groups in which one or more hydrogen atoms directly bonded to atoms constituting the ring have been removed from the above-mentioned heterocyclic groups. Heterocyclic groups include groups in which multiple of these groups are bonded. The heterocyclic group may have a substituent.

[0043] The term "halogen atom" refers to a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

[0044] The "amino group" may have a substituent, and is preferably a substituted amino group (i.e., a secondary amino group or a tertiary amino group, more preferably a tertiary amino group). The substituent that the amino group has is preferably an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, and these groups may further have a substituent. When the amino group has multiple substituents, they may be the same or different, and may be bonded to each other to form a ring together with the nitrogen atom to which they are bonded. Examples of the substituted amino group include a dialkylamino group, a dicycloalkylamino group, a diarylamino group, and groups in which some or all of the hydrogen atoms in these groups have been further substituted with substituents. Examples of the substituted amino group include a dimethylamino group, a diethylamino group, a diphenylamino group, a bis(methylphenyl)amino group, a bis(3,5-di-tert-butylphenyl)amino group, and groups in which some or all of the hydrogen atoms in these groups have been further substituted with substituents.

[0045] The "alkenyl group" may be either linear or branched. The number of carbon atoms in a linear alkenyl group, not including the number of carbon atoms in substituents, is usually 2 to 50, preferably 2 to 20, and more preferably 3 to 10. The number of carbon atoms in a branched alkenyl group, not including the number of carbon atoms in substituents, is usually 3 to 50, preferably 3 to 20, and more preferably 4 to 10.

[0046] The number of carbon atoms in the "cycloalkenyl group" is usually 3 to 50, preferably 4 to 20, and more preferably 5 to 10, not including the number of carbon atoms in substituents. The alkenyl group and the cycloalkenyl group may have a substituent. Examples of the alkenyl group include a vinyl group, a 1-propenyl group, a 2-butenyl group, a 3-butenyl group, a 3-pentenyl group, a 4-pentenyl group, a 1-hexenyl group, a 5-hexenyl group, a 7-octenyl group, and groups in which some or all of the hydrogen atoms in these groups have been substituted with a substituent. Examples of the cycloalkenyl group include a cyclohexenyl group, a cyclohexadienyl group, a cyclooctatrienyl group, a norbornylenyl group, and groups in which some or all of the hydrogen atoms in these groups have been substituted with a substituent.

[0047] The "alkynyl group" may be either linear or branched. The number of carbon atoms in the alkynyl group, not including the carbon atoms of the substituents, is usually 2 to 50, preferably 2 to 20, and more preferably 3 to 10. The number of carbon atoms in a branched alkynyl group, not including the carbon atoms of the substituents, is usually 4 to 50, preferably 4 to 20, and more preferably 4 to 10.

[0048] The number of carbon atoms in the "cycloalkynyl group" is usually 4 to 50, preferably 5 to 20, and more preferably 6 to 10, not including the carbon atoms of the substituents. The alkynyl group and the cycloalkynyl group may have a substituent. Examples of the alkynyl group include an ethynyl group, a 1-propynyl group, a 2-propynyl group, a 2-butynyl group, a 3-butynyl group, a 3-pentynyl group, a 4-pentynyl group, a 1-hexynyl group, a 5-hexynyl group, and the like. Examples of the cycloalkynyl group include a cyclooctynyl group and groups in which some or all of the hydrogen atoms in these groups have been substituted with substituents. Examples of the cycloalkynyl group include a cyclooctynyl group and groups in which some or all of the hydrogen atoms in these groups have been substituted with substituents.

[0049] The "crosslinking group" is a group that can generate a new bond by heating, ultraviolet irradiation, near-ultraviolet irradiation, visible light irradiation, infrared irradiation, radical reaction, etc. The crosslinking group is preferably at least one crosslinking group selected from Group A of crosslinking groups (i.e., at least one group selected from the groups represented by Formulae (XL-1) to (XL-19)).

[0050] (Bridging group A group) [ka] [In the formula, R XL represents a methylene group, an oxygen atom, or a sulfur atom; n XL represents an integer from 0 to 5. XL When there are multiple n, they may be the same or different. XL When there are a plurality of groups, they may be the same or different. *1 indicates the bonding position. These bridging groups may have a substituent, and when there are a plurality of such substituents, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded.]

[0051] Examples of the "substituent" include a halogen atom, a cyano group, an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an amino group, a substituted amino group, an alkenyl group, a cycloalkenyl group, an alkynyl group, and a cycloalkynyl group. The substituent may be a bridging group. When multiple substituents are present, they may be the same or different. When multiple substituents are present, they may be bonded to each other to form a ring together with the atoms to which they are bonded, but it is preferable that they do not form a ring.

[0052] Examples of the "divalent group" include an alkylene group, a cycloalkylene group, an arylene group, a divalent heterocyclic group, -Si(R 0 )2-, -Ge(R 0 )2-, a group represented by -N(R 0 )-, -B(R0 )-, a group represented by -P(R 0 )-, a group represented by -(O=)P(R 0 )-, a group represented by -O-, a group represented by -S-, a group represented by -Se-, a group represented by -S(=O)-, a group represented by -S(=O)2-, and a group represented by -C(=O)-. Divalent groups include groups in which a plurality of these groups are bonded. The divalent group may have a substituent. When a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. R 0 represents a hydrogen atom or a substituent. 0 If there are multiple They may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. R 0 Examples of the substituent include a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a monovalent heterocyclic group, a substituted amino group, a halogen atom, and a cyano group, and are preferably a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of the substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded.

[0053] The "divalent or higher valent group" may be a divalent group or a trivalent or higher valent group. A trivalent or higher valent group means a group in which one or more hydrogen atoms have been removed from a divalent group. For example, in the case of a trivalent group, -N(R 0 )-, -B(R 0 )-, -P(R 0 )- and -(O=)P(R 0 )-, R 0 represents a bond. For example, in the case of a tetravalent group, -Si(R 0 )2- and -Ge(R 0 )2-, R 0 represents a bond. The divalent or more groups include groups in which multiple divalent or more groups are bonded. The divalent or more groups may have a substituent. When multiple substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded.

[0054] In this specification, the absolute value of the difference between the energy level of the lowest excited triplet state and the energy level of the lowest excited singlet state (hereinafter referred to as "ΔE ST The value of ΔE is calculated as follows. First, the ground state of the compound is optimized using the density functional theory at the B3LYP level. In this case, 6-31G* is used as the basis function. Then, using the optimized structure, the ΔE of the compound is calculated using the time-dependent density functional theory at the B3LYP level. ST However, if an atom for which 6-31G* cannot be used is included, LANL2DZ is used for that atom. The quantum chemistry calculation program used for the calculation is Gaussian09.

[0055] [Low molecular compound (b)] The low molecular weight compound (b) of this embodiment is a low molecular weight compound having a heterocyclic skeleton (b) in which six or more rings are fused (hereinafter also referred to as "a heterocyclic skeleton (b) with six or more rings"). The heterocyclic skeleton (b) contains a boron atom, a nitrogen atom, an oxygen atom, a sulfur atom, a selenium atom, and sp 3 and at least one carbon atom selected from the group consisting of carbon atoms in the fused ring. The low molecular weight compound (b) is preferably a compound that does not contain a transition metal element (that is, a compound that is composed only of main group elements).

[0056] The number of carbon atoms contained in the fused ring of the heterocyclic skeleton (b), not including the number of carbon atoms of the substituent, is usually 1 to 500, may be 1 to 300, or may be 5 to 100, and is preferably 10 to 90, more preferably 15 to 80, even more preferably 20 to 70, particularly preferably 25 to 60, and especially preferably 30 to 50, since this provides a more excellent external quantum efficiency for the light-emitting device of this embodiment. The number of heteroatoms contained in the fused ring of the heterocyclic skeleton (b), not including the number of heteroatoms of the substituents, is usually 2 to 50, may be 2 to 40, or may be 2 to 30, and is preferably 3 to 25, more preferably 4 to 20, even more preferably 5 to 15, and particularly preferably 6 to 10, since this provides a more excellent external quantum efficiency for the light-emitting device of this embodiment. The number of boron atoms contained in the fused ring of the heterocyclic skeleton (b), not including the number of boron atoms in the substituent, is usually 1 to 20, and may be 1 to 15. In order to improve the external quantum efficiency of the light-emitting device of this embodiment, the number is preferably 2 to 10, more preferably 2 to 7, even more preferably 2 to 5, particularly preferably 2 or 3, and especially preferably 2.

[0057] The nitrogen atom, oxygen atom, sulfur atom, selenium atom and sp atom contained in the fused ring of the heterocyclic skeleton (b) 3 The total number of carbon atoms, not including the number of atoms of the substituents, is 1 or more (however, when the heterocyclic skeleton (b) satisfies the requirement (i), it is 4 or more. When the heterocyclic skeleton (b) satisfies the requirement (ii), it is 2 or more). Since the external quantum efficiency of the light-emitting device of this embodiment is more excellent, it is preferably 2 or more, more preferably 3 or more, and particularly preferably 4 or more. In addition, the nitrogen atom, oxygen atom, sulfur atom, selenium atom, and sp atom contained in the fused ring of the heterocyclic skeleton (b) are preferably 2 or more, more preferably 3 or more, and particularly preferably 4 or more. 3 The total number of carbon atoms, not including the number of substituent atoms, is usually 30 or less, may be 25 or less, or may be 20 or less, and is preferably 15 or less, more preferably 10 or less, even more preferably 8 or less, particularly preferably 6 or less, and especially preferably 4 or less, since the external quantum efficiency of the light-emitting element of this embodiment is better.

[0058] When the heterocyclic skeleton (b) contains a nitrogen atom in the fused ring, the number of nitrogen atoms contained in the fused ring of the heterocyclic skeleton (b), not including the number of nitrogen atoms of the substituent, is 1 or more (however, when the heterocyclic skeleton (b) satisfies requirement (ii), the number is 2 or more). Since the external quantum efficiency of the light-emitting device of this embodiment is more excellent, the number is preferably 2 or more, more preferably 3 or more, and even more preferably 4 or more. Furthermore, when the heterocyclic skeleton (b) contains a nitrogen atom in the fused ring, the number of nitrogen atoms contained in the fused ring of the heterocyclic skeleton (b), not including the number of nitrogen atoms of the substituent, is usually 30 or less, and may be 25 or less, or may be 20 or less. Since the external quantum efficiency of the light-emitting device of this embodiment is more excellent, the number is preferably 15 or less, more preferably 10 or less, even more preferably 8 or less, particularly preferably 6 or less, and especially preferably 4 or less.

[0059] When the heterocyclic skeleton (b) contains a nitrogen atom in the fused ring, the external quantum efficiency of the light-emitting element of this embodiment is better, so it is preferable that at least one of the nitrogen atoms contained in the heterocyclic skeleton (b) is a nitrogen atom that does not form a double bond, and it is more preferable that all of the nitrogen atoms contained in the heterocyclic skeleton (b) are nitrogen atoms that do not form a double bond.

[0060] When the heterocyclic skeleton (b) contains a nitrogen atom in a fused ring, the number of nitrogen atoms not forming a double bond contained in the fused ring of the heterocyclic skeleton (b), not including the number of nitrogen atoms not forming a double bond of the substituent, is 1 or more (however, when the heterocyclic skeleton (b) satisfies requirement (ii), the number is 2 or more). Since the external quantum efficiency of the light-emitting device of this embodiment is more excellent, the number is preferably 2 or more, more preferably 3 or more, and even more preferably 4 or more. Furthermore, when the heterocyclic skeleton (b) contains a nitrogen atom in a fused ring, the number of nitrogen atoms not forming a double bond contained in the fused ring of the heterocyclic skeleton (b), not including the number of nitrogen atoms not forming a double bond of the substituent, is usually 30 or less, may be 25 or less, or may be 20 or less. Since the external quantum efficiency of the light-emitting device of this embodiment is more excellent, the number is preferably 15 or less, more preferably 10 or less, even more preferably 8 or less, particularly preferably 6 or less, and especially preferably 4 or less.

[0061] The heterocyclic skeleton (b) preferably contains a boron atom and at least one selected from the group consisting of a nitrogen atom, an oxygen atom, a sulfur atom, and a selenium atom in the fused ring, since this provides a light-emitting device of this embodiment with a better external quantum efficiency; more preferably contains a boron atom and at least one selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom in the fused ring; still more preferably contains a boron atom and at least one selected from the group consisting of a nitrogen atom and an oxygen atom in the fused ring; particularly preferably contains a boron atom and a nitrogen atom in the fused ring; and particularly preferably contains a nitrogen atom that does not form a double bond with the boron atom in the fused ring.

[0062] The number of rings constituting the fused rings of the heterocyclic skeleton (b) is preferably 7 or more, more preferably 8 or more, and even more preferably 9 or more, since the external quantum efficiency of the light-emitting device of this embodiment is superior. The number of rings constituting the fused rings of the heterocyclic skeleton (b) is usually 60 or less, and since the external quantum efficiency of the light-emitting device of this embodiment is superior, the number is preferably 40 or less, more preferably 30 or less, even more preferably 25 or less, particularly preferably 20 or less, especially preferably 15 or less, and especially more preferably 13 or less.

[0063] The low molecular weight compound (b) having a heterocyclic skeleton (b) can also be referred to as a low molecular weight compound having a heterocyclic group (b) containing a heterocyclic skeleton (b).

[0064] The heterocyclic group (b) is a group consisting of a boron atom, a nitrogen atom, an oxygen atom, a sulfur atom, a selenium atom, and sp 3 The heterocyclic skeleton (b) may be a group in which one or more hydrogen atoms directly bonded to atoms constituting the ring have been removed from a heterocyclic skeleton (b) having 6 or more rings and containing, in a fused ring, at least one kind selected from the group consisting of carbon atoms, and the group may have a substituent.

[0065] The substituent that the heterocyclic group (b) may have is preferably a halogen atom, a cyano group, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an aryl group, a monovalent heterocyclic group, or a substituted amino group, because the external quantum efficiency of the light-emitting element of this embodiment is more excellent; more preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group, or a substituted amino group; even more preferably an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group, or a substituted amino group; and particularly preferably an alkyl group, a cycloalkyl group, an aryl group, or a substituted amino group, and these groups may further have a substituent.

[0066] The aryl group in the substituent that the heterocyclic group (b) may have is preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from a monocyclic or bicyclic to hexacyclic aromatic hydrocarbon ring, since this provides a more excellent external quantum efficiency for the light-emitting element of this embodiment; more preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from a monocyclic, bicyclic or tricyclic aromatic hydrocarbon ring; even more preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from a monocyclic or tricyclic aromatic hydrocarbon ring; and particularly preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from a monocyclic aromatic hydrocarbon ring; and these groups may further have a substituent.

[0067] The aryl group in the substituent that the heterocyclic group (b) may have is preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from benzene, naphthalene, indene, anthracene, phenanthrene, dihydrophenanthrene, or fluorene, more preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from benzene, naphthalene, anthracene, phenanthrene, or fluorene, even more preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from benzene or fluorene, and particularly preferably a phenyl group, and these groups may have a substituent, because the external quantum efficiency of the light-emitting element of this embodiment is further improved. The aryl group in the substituent that the heterocyclic group (b) may have may be an aryl group having three or more substituents as described below.

[0068] The monovalent heterocyclic group in the substituent that the heterocyclic group (b) may have is preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring is removed from a monocyclic or bicyclic to hexacyclic heterocycle, more preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring is removed from a monocyclic, bicyclic or tricyclic heterocycle, and even more preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring is removed from a monocyclic or tricyclic heterocycle, because the external quantum efficiency of the light-emitting device of this embodiment is more excellent. A group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from the ring, and particularly preferred is a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from a tricyclic heterocycle, and these groups may have a substituent.

[0069] The monovalent heterocyclic group in the substituent that the heterocyclic group (b) may have is preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from furan, thiophene, pyrrole, diazole, triazole, pyridine, diazabenzene, triazine, benzofuran, benzothiophene, indole, azanaphthalene, diazanaphthalene, carbazole, dibenzofuran, dibenzothiophene, phenoxazine, phenothiazine, 9,10-dihydroacridine, 5,10-dihydrophenazine, acridone, azaanthracene, diazaanthracene, azaphenanthrene, or diazaphenanthrene, because the external quantum efficiency of the light-emitting element of this embodiment is further improved, and more preferably pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, carbazole, or dibenzofuran. , dibenzothiophene, phenoxazine, phenothiazine, 9,10-dihydroacridine, or 5,10-dihydrophenazine, by removing one hydrogen atom directly bonded to an atom constituting the ring, more preferably a group obtained by removing one hydrogen atom directly bonded to an atom constituting the ring from pyridine, diazabenzene, triazine, carbazole, phenoxazine, phenothiazine, 9,10-dihydroacridine, or 5,10-dihydrophenazine, particularly preferably a group obtained by removing one hydrogen atom directly bonded to an atom constituting the ring from carbazole, phenoxazine, phenothiazine, 9,10-dihydroacridine, or 5,10-dihydrophenazine, and particularly preferably a group obtained by removing one hydrogen atom directly bonded to an atom constituting the ring from carbazole, and these groups may have a substituent. The monovalent heterocyclic group in the substituent that the heterocyclic group (b) may have may be a monovalent heterocyclic group having three or more substituents as described below.

[0070] In the substituted amino group in the substituent that the heterocyclic group (b) may have, the substituent that the amino group has is preferably an aryl group or a monovalent heterocyclic group, more preferably an aryl group, and these groups may further have a substituent. Examples and preferred ranges of the aryl group and the monovalent heterocyclic group in the substituent that the amino group has are the same as the examples and preferred ranges of the aryl group and the monovalent heterocyclic group in the substituent that the heterocyclic group (b') may have, respectively.

[0071] The substituent that the heterocyclic group (b) may further have is preferably a halogen atom, a cyano group, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an aryl group, a monovalent heterocyclic group, or a substituted amino group, because this will result in a more excellent external quantum efficiency of the light-emitting element of this embodiment. More preferably, it is an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group, or a substituted amino group. Even more preferably, it is an alkyl group, a cycloalkyl group, or an aryl group. Particularly preferably, it is an alkyl group or a cycloalkyl group. These groups may further have a substituent, but it is preferable that they do not have a further substituent. Examples and preferred ranges of the aryl group, monovalent heterocyclic group, and substituted amino group in the substituent that the heterocyclic group (b) may further have are the same as the examples and preferred ranges of the aryl group, monovalent heterocyclic group, and substituted amino group in the substituent that the heterocyclic group (b') may have.

[0072] The term "nitrogen atom not forming a double bond" means a nitrogen atom that is bonded to three other atoms via single bonds. "Containing a nitrogen atom not forming a double bond in the ring" means that -N(R N )-(wherein, R N represents a hydrogen atom or a substituent.) or the formula:

[0073] [ka] This means that the compound contains a group represented by the formula: R N Examples and preferred ranges of R xb The examples and preferred ranges are the same as those of the above.

[0074] The heterocyclic skeleton (b) preferably satisfies at least one of the requirements (i) and (ii), and more preferably satisfies both the requirements (i) and (ii), since the external quantum efficiency of the light-emitting element of this embodiment is superior.

[0075] The low molecular weight compound (b) is preferably a thermally activated delayed fluorescence (TADF) compound, since this provides the light-emitting device of this embodiment with better external quantum efficiency.

[0076] ΔE of low molecular weight compound (b) ST may be, for example, 2.0 eV or less, 1.5 eV or less, 1.0 eV or less, 0.80 eV or less, 0.60 eV or less, or 0.55 eV or less, but since the external quantum efficiency of the light-emitting device of this embodiment is better, it is preferably 0.50 eV or less, more preferably 0.45 eV or less, even more preferably 0.40 eV or less, particularly preferably 0.37 eV or less, especially preferably 0.35 eV or less, especially more preferably 0.33 eV or less, especially even more preferably 0.32 eV or less, and especially especially preferably 0.30 eV or less. ST may be, for example, 0.001 eV or more, 0.01 eV or more, 0.10 eV or more, 0.15 eV or more, 0.20 eV or more, or 0.25 eV or more.

[0077] The molecular weight of the low molecular weight compound (b) is usually 1×10 2 That's 2 x 10 2 May be greater than 3 x 10 2 May be more than 4 x 10 2or more, and is preferably 5×10 because the external quantum efficiency of the light-emitting device of this embodiment is superior. 2 More preferably, it is 6×10 2 More preferably, 8×10 2 More preferably, it is 1.0×10 2 More preferably, it is 1.2×10 3 More preferably, it is 1.4×10 or more. 3 The molecular weight of the low molecular weight compound (b) is usually 1×10 4 The external quantum efficiency of the light-emitting device of this embodiment is superior, and the synthesis of the low-molecular-weight compound (b) is easy, so it is preferably 8 × 10 3 or less, more preferably 6×10 3 or less, and more preferably 4×10 3 or less, and particularly preferably 2 × 10 3 The following is the result.

[0078] sp contained in low molecular weight compound (b) 3 The total number of carbon atoms may be, for example, 1 or more, 3 or more, or 5 or more, and is preferably 7 or more, more preferably 9 or more, even more preferably 10 or more, particularly preferably 15 or more, especially preferably 20 or more, and especially preferably 25 or more, since the external quantum efficiency of the light-emitting device of this embodiment is better. 3 The total number of carbon atoms may be, for example, 1000 or less, 800 or less, 600 or less, 400 or less, or 200 or less. In order to improve the external quantum efficiency of the light-emitting device of this embodiment and to facilitate the synthesis of the low-molecular compound (b), the total number of carbon atoms is preferably 100 or less, more preferably 70 or less, and even more preferably 100 or less. It is preferably 50 or less, and particularly preferably 30 or less.

[0079] The low molecular weight compound (b) may have at least one selected from the group consisting of an aryl group having three or more substituents and a monovalent heterocyclic group having three or more substituents. Since the external quantum efficiency of the light-emitting device of this embodiment is more excellent, the low molecular weight compound (b) preferably has at least one selected from the group consisting of an aryl group having three or more substituents and a monovalent heterocyclic group having three or more substituents, and more preferably has an aryl group having three or more substituents, and these groups may further have substituents. Examples and preferred ranges of the aryl group and monovalent heterocyclic group in the aryl group having three or more substituents and the monovalent heterocyclic group having three or more substituents are the same as the examples and preferred ranges of the aryl group and monovalent heterocyclic group in the substituent that the heterocyclic group (b) may have, respectively. In the aryl group having three or more substituents and the monovalent heterocyclic group having three or more substituents, examples and preferred ranges of the substituents are the same as the examples and preferred ranges of the substituents that the substituents that the heterocyclic group (b) may further have.

[0080] In the aryl group having three or more substituents and the monovalent heterocyclic group having three or more substituents, the number of substituents is usually 3 to 50, and is preferably 3 to 20, more preferably 3 to 15, even more preferably 3 to 10, particularly preferably 3 to 7, especially preferably 3 to 5, and especially preferably 3 or 4, because the external quantum efficiency of the light-emitting device of this embodiment is superior and the synthesis of the low molecular weight compound (b) is easy.

[0081] When the low molecular weight compound (b) has at least one selected from the group consisting of an aryl group having three or more substituents and a monovalent heterocyclic group having three or more substituents, the total number of the aryl group having three or more substituents and the monovalent heterocyclic group having three or more substituents contained in the low molecular weight compound (b) is usually 1 to 50, and is preferably 1 to 20, more preferably 1 to 10, even more preferably 1 to 7, and particularly preferably 1 to 4, since this results in a superior external quantum efficiency of the light-emitting device of this embodiment and also simplifies the synthesis of the low molecular weight compound (b).

[0082] When the low molecular weight compound (b) has at least one selected from the group consisting of an aryl group having three or more substituents and a monovalent heterocyclic group having three or more substituents, the low molecular weight compound (b) is not particularly limited as long as it has at least one selected from the group consisting of an aryl group having three or more substituents and a monovalent heterocyclic group having three or more substituents. When the low molecular weight compound (b) has at least one selected from the group consisting of an aryl group having three or more substituents and a monovalent heterocyclic group having three or more substituents, the low molecular weight compound (b) may have at least one selected from the group consisting of an aryl group having three or more substituents and a monovalent heterocyclic group having three or more substituents, for example, as a substituent that the heterocyclic group (b) may have, or may have as a further substituent that the substituent that the heterocyclic group (b) may have, but preferably as a substituent that the heterocyclic group (b) may have, because the external quantum efficiency of the light-emitting device of this embodiment is more excellent.

[0083] When the low molecular weight compound (b) has an aryl group having three or more substituents, the aryl group in the substituent that the heterocyclic group (b) may have may be an aryl group having three or more substituents, and in the substituted amino group in the substituent that the heterocyclic group (b) may have, the aryl group in the substituent that the amino group has may be an aryl group having three or more substituents. Also, when the low molecular weight compound (b) has a monovalent heterocyclic group having three or more substituents, the monovalent heterocyclic group in the substituent that the heterocyclic group (b) may have may be a monovalent heterocyclic group having three or more substituents, and In the substituted amino group in the optional substituent, the monovalent heterocyclic group in the substituent that the amino group has may be a monovalent heterocyclic group having three or more substituents.

[0084] The low molecular weight compound (b) has a higher external quantum efficiency than the light-emitting device of this embodiment, and therefore, the sp 3 Preferably, the total number of carbon atoms is 9 or more, or the low molecular weight compound (b) has at least one selected from the group consisting of an aryl group having three or more substituents and a monovalent heterocyclic group having three or more substituents. 3 The total number of carbon atoms is more preferably 9 or more, and the sp 3 It is more preferable that the total number of carbon atoms is 9 or more, and the low molecular weight compound (b) has at least one selected from the group consisting of an aryl group having three or more substituents and a monovalent heterocyclic group having three or more substituents.

[0085] The low molecular weight compound (b) is preferably a low molecular weight compound having a heterocyclic skeleton represented by formula (b0) (i.e., the heterocyclic skeleton (b) is a heterocyclic skeleton represented by formula (b0)), since this results in a higher external quantum efficiency of the light-emitting device of this embodiment. Unless otherwise specified, the examples and preferred ranges of the low molecular weight compound (b) described above can also be applied as examples and preferred ranges to low molecular weight compounds having a heterocyclic skeleton represented by the formula (b0) described below.

[0086] [ka] [In the formula, X b1 and X b2 are each independently an oxygen atom, a sulfur atom, a selenium atom, -N(R xb )-, an alkylene group, or a cycloalkylene group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. R xb represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. Ar b1 , Ar b2 and Ar b3 each independently represents an aromatic hydrocarbon group or a heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. X b1 and Ar b1 , X b1 and Ar b2 , X b2 and Ar b1 , X b2 and Ar b3 , and Ar b2 and Ar b3may each independently bond directly or via a divalent or higher valent group which may have a substituent to form a ring. When a plurality of such substituents are present, they may be the same or different and may bond to each other to form a ring together with the atoms to which they are bonded. However, the formula (b0) satisfies at least one of the requirements (b0-i) and (b0-ii). (b0-i)Ar b1 , Ar b2 and Ar b3 At least one of the groups is a polycyclic aromatic hydrocarbon group or a polycyclic heterocyclic group, and these groups may have a substituent. (b0-ii)X b1 and Ar b1 , X b1 and Ar b2 , X b2 and Ar b1 , X b2 and Ar b3 , and Ar b2 and Ar b3 At least one of the groups is bonded directly or via a divalent or higher valent group which may have a substituent to form a ring. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atom to which they are bonded.]

[0087] When the low molecular weight compound (b) satisfies the requirement (i), the nitrogen atom, oxygen atom, sulfur atom, selenium atom, and sp atom contained in the ring of the heterocyclic skeleton represented by formula (b0) are 3 The total number of carbon atoms, not including the number of atoms of the substituents, is 4 or more. When the low-molecular-weight compound (b) satisfies the requirement (i), the nitrogen atom, oxygen atom, sulfur atom, selenium atom, and sp atom contained in the fused ring of the heterocyclic skeleton represented by formula (b0) are 3 Examples and preferred ranges of the total number of carbon atoms include the nitrogen atom, oxygen atom, sulfur atom, selenium atom, and sp atom contained in the fused ring of the heterocyclic skeleton (b) when the low molecular weight compound (b) satisfies the requirement (i). 3 The examples and preferred ranges for the total number of carbon atoms are the same as those for the total number of carbon atoms. When low molecular weight compound (b) satisfies requirement (ii), the number of nitrogen atoms contained in the ring of the heterocyclic skeleton represented by formula (b0), not including the number of nitrogen atoms of the substituent, is 2 or more. When low molecular weight compound (b) satisfies requirement (ii), examples and preferred ranges of the number of nitrogen atoms contained in the fused ring of the heterocyclic skeleton represented by formula (b0) are the same as the examples and preferred ranges of the number of nitrogen atoms contained in the fused ring of the heterocyclic skeleton (b) when low molecular weight compound (b) satisfies requirement (ii).

[0088] X b1 and X b2 is preferably an oxygen atom, a sulfur atom, a selenium atom, or —N(R xb )- or an alkylene group, and more preferably an oxygen atom, a sulfur atom, a selenium atom, or an —N(R xb )-, and more preferably an oxygen atom, a sulfur atom, or a group represented by —N(R xb )-, and particularly preferably an oxygen atom or -N(R xb )-, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded.

[0089] X b1 and X b2 The alkylene group in is preferably a methylene group, ethylene group, propylene group, butylene group, pentylene group, or hexylene group, more preferably a methylene group, ethylene group, or propylene group, and even more preferably a methylene group, and these groups may have a substituent. X b1 and X b2 The cycloalkylene group in the formula (I) is preferably a cyclopropylene group, a cyclobutylene group, a cyclopentylene group or a cyclohexylene group, more preferably a cyclohexylene group, and these groups may have a substituent. X b1 and X b2The examples and preferred range of the substituents which may be possessed by the heterocyclic group (b) are the same as the examples and preferred range of the substituents which may be possessed by the heterocyclic group (b).

[0090] R xb is preferably an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, more preferably an aryl group or a monovalent heterocyclic group, and even more preferably an aryl group, since the external quantum efficiency of the light-emitting element of this embodiment is superior. These groups may have a substituent. R xb The examples and preferred ranges of the aryl group and the monovalent heterocyclic group in are the same as the examples and preferred ranges of the aryl group and the monovalent heterocyclic group in the substituent that the heterocyclic group (b) may have, respectively. R xb The examples and preferred range of the substituents which may be possessed by the heterocyclic group (b) are the same as the examples and preferred range of the substituents which may be possessed by the heterocyclic group (b).

[0091] Ar b1 , Ar b2 and Ar b3 The aromatic hydrocarbon group in the formula (I) is a monocyclic aromatic hydrocarbon group or a polycyclic aromatic hydrocarbon group, and these groups may have a substituent. Ar b1 , Ar b2 and Ar b3 In the above formula, the monocyclic aromatic hydrocarbon group is a group in which one or more hydrogen atoms directly bonded to atoms constituting the ring have been removed from a monocyclic aromatic hydrocarbon ring, and the group may have a substituent.

[0092] Ar b1 , Ar b2 and Ar b3 In the formula, the number of carbon atoms in the monocyclic aromatic hydrocarbon group, not including the number of carbon atoms in the substituent, is preferably 6 to 20, more preferably 6 to 10, and even more preferably 6. The monocyclic aromatic hydrocarbon ring in the monocyclic aromatic hydrocarbon group is preferably benzene, as this provides the light-emitting device of this embodiment with better external quantum efficiency.

[0093] Ar b1 , Ar b2 and Ar b3 In the formula (I), the polycyclic aromatic hydrocarbon group is a group in which one or more hydrogen atoms directly bonded to atoms constituting the ring have been removed from a polycyclic aromatic hydrocarbon ring, and the group may have a substituent.

[0094] Ar b1 , Ar b2 and Ar b3 In the formula, the number of carbon atoms of the polycyclic aromatic hydrocarbon group is usually 7 to 60, preferably 8 to 60, more preferably 9 to 40, and even more preferably 10 to 20, not including the number of carbon atoms of the substituent. Ar b1 , Ar b2 and Ar b3 In the above, the polycyclic aromatic hydrocarbon ring in the polycyclic aromatic hydrocarbon group is preferably a bicyclic to heptacyclic aromatic hydrocarbon ring, more preferably a bicyclic to pentacyclic aromatic hydrocarbon ring, still more preferably a bicyclic or tricyclic aromatic hydrocarbon ring, particularly preferably naphthalene, indene, anthracene, phenanthrene, dihydrophenanthrene, or fluorene, since this provides a light-emitting element of this embodiment with better external quantum efficiency.

[0095] Ar b1 , Ar b2 and Ar b3 The aromatic hydrocarbon group in the formula (I) is preferably a monocyclic aromatic hydrocarbon group, and more preferably a group in which one or more hydrogen atoms directly bonded to atoms constituting the ring have been removed from benzene, since this provides a light-emitting element of this embodiment with better external quantum efficiency. These groups may have a substituent.

[0096] Ar b1 , Ar b2 and Ar b3 The heterocyclic group in the formula (I) is a monocyclic heterocyclic group or a polycyclic heterocyclic group, and these groups may have a substituent. Arb1 , Ar b2 and Ar b3 In the above formula, the monocyclic heterocyclic group is a group in which one or more hydrogen atoms directly bonded to atoms constituting the ring have been removed from a monocyclic heterocycle, and the group may have a substituent.

[0097] Ar b1 , Ar b2 and Ar b3 In the above formula, the number of carbon atoms in the monocyclic heterocyclic group, not including the number of carbon atoms in the substituents, is preferably 1 to 20, more preferably 1 to 10, even more preferably 2 to 6, and particularly preferably 3 to 5. The number of heteroatoms in the monocyclic heterocyclic group, not including the number of heteroatoms in the substituents, is preferably 1 to 10, more preferably 1 to 5, even more preferably 1 to 3, and particularly preferably 1 or 2. Ar b1 , Ar b2 and Ar b3 In the above formula, the monocyclic heterocycle in the monocyclic heterocyclic group is preferably furan, thiophene, pyrrole, triazole, pyridine, diazabenzene, or triazine, because the external quantum efficiency of the light-emitting element of this embodiment is more excellent, more preferably furan, thiophene, pyrrole, triazole, pyridine, or diazabenzene, and even more preferably pyridine or diazabenzene.

[0098] Ar b1 , Ar b2 and Ar b3 In the above, the polycyclic heterocyclic group is a group consisting of a polycyclic heterocyclic ring and a It is a group in which one or more hydrogen atoms directly bonded to atoms constituting the ring have been removed, and the group may have a substituent. Ar b1 , Ar b2 and Ar b3 In the above, the polycyclic heterocyclic ring in the polycyclic heterocyclic group may be a heterocyclic ring having a polycyclic heterocyclic skeleton (b') described later, or may be a heterocyclic ring not having a polycyclic heterocyclic skeleton (b') described later. b1 , Ar b2 and Ar b3In the formula (I), the polycyclic heterocyclic group may be the heterocyclic group (b') described below, or may be a heterocyclic group (Nb') in which one or more hydrogen atoms directly bonded to atoms constituting the ring have been removed from a heterocycle not having a polycyclic heterocyclic skeleton (b').

[0099] The number of carbon atoms contained in the ring of the heterocyclic group (Nb'), not including the number of carbon atoms of the substituent, is usually 1 to 60, preferably 5 to 40, and more preferably 8 to 20. The number of heteroatoms contained in the ring of the heterocyclic group, not including the number of heteroatoms of the substituent, is usually 1 to 30, preferably 1 to 10, more preferably 1 to 5, even more preferably 1 to 3, and particularly preferably 1 or 2.

[0100] In the heterocyclic group (Nb'), the heterocycle not having a heterocyclic skeleton (b') is not particularly limited as long as it is a heterocycle not having a heterocyclic skeleton (b') described below. A polycyclic heterocycle not having a heterocyclic skeleton (b') provides the light-emitting device of this embodiment with better external quantum efficiency, and is therefore preferably a bicyclic to heptacyclic heterocycle not having a heterocyclic skeleton (b'), more preferably a bicyclic to pentacyclic heterocycle not having a heterocyclic skeleton (b'), still more preferably a bicyclic or tricyclic heterocycle not having a heterocyclic skeleton (b'), and particularly preferably a tricyclic heterocycle not having a heterocyclic skeleton (b'). A heterocycle not having a polycyclic heterocyclic skeleton (b') provides the light-emitting device of this embodiment with even better external quantum efficiency, and is therefore preferably selected from the group consisting of azanaphthalene, diazanaphthalene, benzofuran, benzothiophene, indole, azaindole, diazaindole, dibenzofuran, dibenzothiophene, dibenzoselenophene, carbazole, azacarbazole, diazacarbazole, phenoxazine, phenothiazine, 9,10-dihydroacridine, 5,10-dihydrophenazine, acridone, azaanthracene, diazaanthracene, and azaisophenone. azaphenanthrene or diazaphenanthrene, more preferably azanaphthalene, diazanaphthalene, dibenzofuran, dibenzothiophene, carbazole, azacarbazole, diazacarbazole, azaanthracene, diazaanthracene, azaphenanthrene or diazaphenanthrene, still more preferably azanaphthalene, diazanaphthalene, azaanthracene, diazaanthracene, azaphenanthrene or diazaphenanthrene, and particularly preferably azaphenanthrene or diazaphenanthrene.

[0101] The heterocyclic skeleton (b') is composed of a boron atom, a nitrogen atom, an oxygen atom, a sulfur atom, a selenium atom, and sp 3 and at least one selected from the group consisting of carbon atoms in a fused ring.

[0102] The number of carbon atoms contained in the fused ring of the heterocyclic skeleton (b') is usually 1 to 60, preferably 5 to 50, more preferably 10 to 40, and even more preferably 15 to 30, not including the number of carbon atoms of the substituent. The number of heteroatoms contained in the fused ring of the heterocyclic skeleton (b'), not including the number of heteroatoms of the substituents, is usually 2 to 30, preferably 2 to 15, more preferably 2 to 10, even more preferably 2 to 5, and particularly preferably 2 or 3. The number of boron atoms contained in the fused ring of the heterocyclic skeleton (b') is usually 1 to 10, preferably 1 to 5, more preferably 1 to 3, and even more preferably 1, not including the number of boron atoms in the substituents. The nitrogen atom, oxygen atom, sulfur atom, selenium atom and sp atom contained in the fused ring of the heterocyclic skeleton (b') 3 The total number of carbon atoms, not including the number of substituent atoms, is usually 1 to 20. It is preferably 1 to 10, more preferably 1 to 5, even more preferably 1 to 3, and particularly preferably 2.

[0103] The heterocyclic skeleton (b') preferably contains a boron atom and at least one selected from the group consisting of a nitrogen atom, an oxygen atom, a sulfur atom, and a selenium atom in the fused ring, since this improves the external quantum efficiency of the light-emitting device of this embodiment; more preferably contains a boron atom and at least one selected from the group consisting of a nitrogen atom, an oxygen atom, and a sulfur atom in the fused ring; still more preferably contains a boron atom and at least one selected from the group consisting of a nitrogen atom and an oxygen atom in the fused ring; particularly preferably contains a boron atom and a nitrogen atom in the fused ring; and especially preferably contains a nitrogen atom that does not form a double bond with the boron atom in the fused ring.

[0104] The heterocyclic skeleton (b') is preferably a heterocyclic skeleton having two or more rings, more preferably a heterocyclic skeleton having three or more rings, even more preferably a heterocyclic skeleton having four or more rings, and particularly preferably a heterocyclic skeleton having five or more rings, since this provides a more excellent external quantum efficiency for the light-emitting device of this embodiment. Furthermore, the heterocyclic skeleton (b) may be, for example, a heterocyclic skeleton having 40 or fewer rings, or a heterocyclic skeleton having 30 or fewer rings. However, since this provides a more excellent external quantum efficiency for the light-emitting device of this embodiment, it is preferably a heterocyclic skeleton having 20 or fewer rings, more preferably a heterocyclic skeleton having 15 or fewer rings, even more preferably a heterocyclic skeleton having 10 or fewer rings, and particularly preferably a heterocyclic skeleton having 7 or fewer rings.

[0105] The heterocyclic skeleton (b') can also be referred to as a heterocyclic group (b') containing the heterocyclic skeleton (b'). Examples and preferred ranges of the substituents which the heterocyclic group (b') may have are the same as the examples and preferred ranges of the substituents which the heterocyclic group (b) may have.

[0106] Ar b1 , Ar b2 and Ar b3 The heterocyclic group in the formula (I) is preferably a heterocyclic group (Nb') or a heterocyclic group (b'), and more preferably a heterocyclic group (b'), since the external quantum efficiency of the light-emitting element of this embodiment is superior. These groups may have a substituent.

[0107] Ar b1 , Ar b2 and Ar b3 is a monocyclic aromatic hydrocarbon group, a polycyclic aromatic hydrocarbon group, a monocyclic heterocyclic group, a heterocyclic group (Nb') or a heterocyclic group (b'), and is preferably a monocyclic aromatic hydrocarbon group, a group in which one or more hydrogen atoms directly bonded to atoms constituting the ring have been removed from a bicyclic to pentacyclic aromatic hydrocarbon ring, a monocyclic heterocyclic group, a group in which one or more hydrogen atoms directly bonded to atoms constituting the ring have been removed from a bicyclic to pentacyclic heterocyclic ring not having a heterocyclic skeleton (b'), or a heterocyclic group (b'), since the external quantum efficiency of the light-emitting element of this embodiment is more excellent. and a heterocyclic group (b'), more preferably a monocyclic aromatic hydrocarbon group, a monocyclic heterocyclic group, a bicyclic or tricyclic heterocycle not having a heterocyclic skeleton (b') from which one or more hydrogen atoms directly bonded to an atom constituting the ring have been removed, or a heterocyclic group (b'), particularly preferably a monocyclic aromatic hydrocarbon group, a bicyclic or tricyclic heterocycle not having a heterocyclic skeleton (b') from which one or more hydrogen atoms directly bonded to an atom constituting the ring have been removed, or a heterocyclic group (b'), and particularly preferably a monocyclic aromatic hydrocarbon group, a bicyclic or tricyclic heterocycle not having a heterocyclic skeleton (b') from which one or more hydrogen atoms directly bonded to an atom constituting the ring have been removed, or a heterocyclic group (b'), and particularly preferably a monocyclic aromatic hydrocarbon group or a heterocyclic group (b'), and these groups may have a substituent. Ar b1 , Ar b2 and Ar b3The examples and preferred range of the substituents which may be possessed by the heterocyclic group (b) are the same as the examples and preferred range of the substituents which may be possessed by the heterocyclic group (b).

[0108] The low molecular weight compound (b) of this embodiment has a hexacyclic or higher heterocyclic skeleton (b), which results in a more excellent external quantum efficiency of the light-emitting device of this embodiment. Therefore, when formula (b0) satisfies at least one of requirements (b0-i) and (b0-ii), the low molecular weight compound having a heterocyclic skeleton represented by formula (b0) has a hexacyclic or higher heterocyclic skeleton (b), which results in a more excellent external quantum efficiency of the light-emitting device of this embodiment.

[0109] If formula (b0) satisfies requirement (b0-i), then Ar b1 , Ar b2 and Ar b3 At least one of the groups is a polycyclic aromatic hydrocarbon group or a polycyclic heterocyclic group, and since the external quantum efficiency of the light-emitting element of this embodiment is more excellent, it is preferably a polycyclic heterocyclic group, more preferably a group in which one or more hydrogen atoms directly bonded to atoms constituting the ring have been removed from a bicyclic to pentacyclic heterocycle not having a heterocyclic skeleton (b'), or a heterocyclic group (b'), even more preferably a group in which one or more hydrogen atoms directly bonded to atoms constituting the ring have been removed from a bicyclic or tricyclic heterocycle not having a heterocyclic skeleton (b'), or a heterocyclic group (b'), and particularly preferably a heterocyclic group (b'), and these groups may have a substituent.

[0110] When the formula (b0) satisfies the requirement (b0-i), the external quantum efficiency of the light-emitting device of this embodiment is superior, so Ar b1 , Ar b2 and Ar b3 At least one of the groups (a) and (b) is preferably a polycyclic heterocyclic group, more preferably a heterocyclic group (b'), and these groups may have a substituent.

[0111] When formula (b0) satisfies requirement (b0-i), the external quantum efficiency of the light-emitting device of this embodiment is superior, and therefore, preferably, Ar b1and Ar b2 At least one of Ar is a polycyclic aromatic hydrocarbon group or a polycyclic heterocyclic group (preferably a polycyclic heterocyclic group), b2 is more preferably a polycyclic aromatic hydrocarbon group or a polycyclic heterocyclic group (preferably a polycyclic heterocyclic group), and Ar b2 is more preferably a heterocyclic group (b'), and these groups may have a substituent.

[0112] Formula (b0) satisfies requirement (b0-i) and Ar b1 , Ar b2 and Ar b3 is other than the heterocyclic group (b'), Ar b1 , Ar b2 and Ar b3 Examples and preferred ranges of Ar are described later. b , Ar b4 and Ar b5 The examples and preferred ranges are the same as those of the above.

[0113] When formula (b0) satisfies requirement (b0-i), the heterocyclic group (b') is preferably a group represented by formula (b1'-1) to formula (b1'-4), more preferably a group represented by formula (b1'-2) or formula (b1'-3), and even more preferably a group represented by formula (b1'-2), since the external quantum efficiency of the light-emitting element of this embodiment is more excellent.

[0114] [ka] [In the formula, R xb represents the same meaning as above. Ar b , Ar b4 and Ar b5 each independently represents an aromatic hydrocarbon group or a heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. X b3 , Xb4 and X b5 are each independently an oxygen atom, a sulfur atom, a selenium atom, -N(R xb )-, an alkylene group, or a cycloalkylene group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. n b1’ represents 2 or 3. However, Ar b1 When is a group represented by formula (b1'-1) to formula (b1'-4), n b1’ represents 3. Ar b2 or Ar b3 When is a group represented by formula (b1'-1) to formula (b1'-4), n b1’ represents 2. * b1’ represents the bond position. b1 When the group is represented by formula (b1'-1) to formula (b1'-4), three * b1’ are respectively, X b1 , X b2 and a bond with a boron atom. b2 When is a group represented by formula (b1'-1) to formula (b1'-4), two * b1’ are respectively, X b1 and a bond with a boron atom. b3 When is a group represented by formula (b1'-1) to formula (b1'-4), two * b1’ are respectively, X b2 and a bond with a boron atom. X b3 and Ar b , X b3 and Ar b4 , X b4 and Ar b4 , X b4 and Ar b5 , X b5 and Ar b5 , and X b5 and Ar b may each independently bond directly or via a divalent or higher valent group which may have a substituent to form a ring, and in formula (b1'-1) and formula (b1'-3), Arb4 and Ar b5 may be bonded directly or via a divalent or higher valent group which may have a substituent to form a ring, and in formula (b1'-1) and formula (b1'-2), Ar b and Ar b5 may be bonded directly or via a divalent or higher group which may have a substituent to form a ring. When there are multiple substituents in the divalent or higher group, they may be the same or different and may be bonded to each other to form a ring together with the atom to which they are bonded.

[0115] Ar b , Ar b4 and Ar b5 Examples of the aromatic hydrocarbon group and preferred ranges thereof are as follows: r b1 , Ar b2 and Ar b3 The examples and preferred ranges of the aromatic hydrocarbon group are the same as those in the above. Ar b , Ar b4 and Ar b5 Examples and preferred ranges of the heterocyclic group in b1 , Ar b2 and Ar b3 The examples and preferred ranges of the heterocyclic group are the same as those in Ar b , Ar b4 and Ar b5 The heterocyclic group in (b) is preferably a monocyclic heterocyclic group or a heterocyclic group (Nb'), more preferably a monocyclic heterocyclic group, and these groups may have a substituent, because the external quantum efficiency of the light-emitting element of this embodiment is superior and a low-molecular-weight compound having a heterocyclic skeleton represented by formula (b0) can be easily synthesized.

[0116] Ar b , Ar b4 and Ar b5 is preferably an aromatic hydrocarbon group which may have a substituent, since the external quantum efficiency of the light-emitting element of this embodiment is superior and the synthesis of a low-molecular-weight compound having a heterocyclic skeleton represented by formula (b0) is easy.

[0117] Ar b , Ar b4 and Ar b5 is preferably a monocyclic aromatic hydrocarbon group, a polycyclic monocyclic heterocyclic group, a monocyclic heterocyclic group, or a heterocyclic group (Nb'), since this further improves the external quantum efficiency of the light-emitting device of this embodiment and facilitates the synthesis of a low-molecular-weight compound having a heterocyclic skeleton represented by formula (b0), and more preferably a monocyclic aromatic hydrocarbon group, a group in which one or more hydrogen atoms directly bonded to atoms constituting the ring have been removed from a bicyclic to pentacyclic aromatic hydrocarbon ring, a monocyclic heterocyclic group, or a group in which one or more hydrogen atoms directly bonded to atoms constituting the ring have been removed from a bicyclic to pentacyclic heterocycle not having a heterocyclic skeleton (b'), and even more preferably Preferably, it is a monocyclic aromatic hydrocarbon group, a group in which one or more hydrogen atoms directly bonded to an atom constituting the ring have been removed from a bicyclic or tricyclic aromatic hydrocarbon ring, a monocyclic heterocyclic group, or a group in which one or more hydrogen atoms directly bonded to an atom constituting the ring have been removed from a bicyclic or tricyclic heterocyclic ring that does not have a heterocyclic skeleton (b'), and particularly preferably, it is a monocyclic aromatic hydrocarbon group, or a group in which one or more hydrogen atoms directly bonded to an atom constituting the ring have been removed from a bicyclic or tricyclic aromatic hydrocarbon ring, and particularly preferably, it is a monocyclic aromatic hydrocarbon group, and these groups may have a substituent. Ar b , Ar b4 and Ar b5 Examples of the substituents that may be possessed by Ar and the preferred ranges thereof are as follows: b1 , Ar b2 and Ar b3 The examples and preferred ranges of the substituents that may be possessed by the group are the same as those of the substituents that may be possessed by the group.

[0118] X b3 , X b4 and X b5 Examples and preferred ranges of X b1 and X b2 The examples and preferred ranges are the same as those of the above. Examples and preferred ranges of the divalent or more groups which may have a substituent in formulas (b1'-1) to (b1'-4) are the same as the examples and preferred ranges of the divalent or more groups which may have a substituent described later in the section regarding the case where formula (b0) satisfies requirement (b0-ii).

[0119] When formula (b0) satisfies requirement (b0-i), the low molecular weight compound having a heterocyclic skeleton represented by formula (b0) provides the light-emitting device of this embodiment with better external quantum efficiency. Therefore, the low molecular weight compound is preferably a low molecular weight compound having a heterocyclic skeleton represented by formulas (b0-1-1) to (b0-1-3) (i.e., the heterocyclic skeleton represented by formula (b0) is the heterocyclic skeleton represented by formulas (b0-1-1) to (b0-1-3)), and more preferably a low molecular weight compound having a heterocyclic skeleton represented by formula (b0-1-1) (i.e., the heterocyclic skeleton represented by formula (b0) is the heterocyclic skeleton represented by formula (b0-1-1)).

[0120] [ka] [In the formula, Ar b , Ar b1 , Ar b2 , Ar b3 , Ar b4 , Ar b5 , X b1 , X b2 , X b3 , X b4 and X b5 has the same meaning as above.]

[0121] In formulas (b0-1-1) to (b0-1-3), Ar b1 , Ar b2 and Ar b3 is other than the heterocyclic group (b'), Ar b1 , Ar b2 and Ar b3 Examples and preferred ranges of Ar b , Ar b4 and Ar b5 The examples and preferred ranges are the same as those of the above.

[0122] Formula (b0) satisfies requirement (b0-ii) and Ar b1 , Ar b2 and Ar b3 is other than the heterocyclic group (b'), Ar b1 , Ar b2 and Ar b3 Examples and preferred ranges of Ar b , Ar b4 and Ar b5 The examples and preferred ranges are the same as those of the above.

[0123] When the formula (b0) satisfies the requirement (b0-ii), the external quantum efficiency of the light-emitting device of this embodiment is superior, and therefore, X b1 and Ar b1 , X b1 and Ar b2 , X b2 and Ar b1 , and X b2 and Ar b3 Preferably, at least one of the following is bonded directly or via a divalent or higher valent group which may have a substituent to form a ring; and X b1 and Ar b2 , and X b2 and Ar b3 It is more preferable that at least one of the following is bonded directly or via a divalent or higher valent group which may have a substituent to form a ring; and X b2 and Ar b3 However, it is more preferable that they are bonded directly or via a divalent or higher valent group which may have a substituent to form a ring.

[0124] When formula (b0) satisfies requirement (b0-ii), the divalent or higher valent group is preferably a divalent to tetravalent group, more preferably a divalent or trivalent group, because the external quantum efficiency of the light-emitting element of this embodiment is superior and the low-molecular-weight compound represented by formula (b0) is easily synthesized, and these groups may have a substituent.

[0125] When formula (b0) satisfies requirement (b0-ii), the divalent group is preferably an alkylene group, a cycloalkylene group, or -N(R 0 )-, -B(R 0 )-, a group represented by -O-, a group represented by -S-, or a group represented by -Se-, and more preferably an alkylene group, -N(R 0 )-, -B(R 0 )-, -O-, -S- or -Se-, and more preferably -N(R 0 )-, -B(R 0 )-, -O-, -S- or -Se-, and particularly preferably -N(R 0 )-, -B(R 0 )-, -O-, or -S-, and particularly preferably -N(R 0 )-, -B(R 0 )- or -O-, and these groups may have a substituent.

[0126] When formula (b0) satisfies requirement (b0-ii), the trivalent group is preferably a group in which one hydrogen atom has been removed from an alkylene group, a group in which one hydrogen atom has been removed from a cycloalkylene group, or a group represented by formula (Xb0-1), because this provides a light-emitting element of this embodiment with better external quantum efficiency and facilitates the synthesis of a low-molecular-weight compound having a heterocyclic skeleton represented by formula (b0), more preferably a group in which one hydrogen atom has been removed from an alkylene group or a group represented by formula (Xb0-1), and even more preferably a group represented by formula (Xb0-1), and these groups may have a substituent.

[0127] [ka] [where, X b0-1is a boron atom, a nitrogen atom, a phosphorus atom, P(=O), Si(R 0 ) or Ge(R 0 ) represents.

[0128] X b0-1 is preferably a boron atom, a nitrogen atom, a phosphorus atom, or P(═O), more preferably a boron atom or a nitrogen atom, and even more preferably a boron atom, since this provides a better external quantum efficiency for the light-emitting element of this embodiment.

[0129] When formula (b0) satisfies requirement (b0-ii), the tetravalent group is preferably a group in which two hydrogen atoms have been removed from an alkylene group, a group in which two hydrogen atoms have been removed from a cycloalkylene group, or a group represented by formula (Xb0-2), because this provides a light-emitting element of this embodiment with better external quantum efficiency and facilitates the synthesis of a low-molecular-weight compound having a heterocyclic skeleton represented by formula (b0), and more preferably a group in which two hydrogen atoms have been removed from an alkylene group or a group represented by formula (Xb0-2), and these groups may have a substituent.

[0130] [ka] [where, X b0-2 represents a silicon atom or a germanium atom.

[0131] R in a divalent or higher group when formula (b0) satisfies requirement (b0-ii) 0 Examples and preferred ranges of R xb In the divalent or higher valent group in the case where formula (b0) satisfies requirement (b0-ii), examples and preferred ranges of the alkylene group and cycloalkylene group are the same as those of X b1 and X b2 When formula (b0) satisfies requirement (b0-ii), examples and preferred ranges of the substituents that the divalent or higher group may have are the same as the examples and preferred ranges of the substituents that the heterocyclic group (b) may have.

[0132] When formula (b0) satisfies requirement (b0-ii), the low molecular weight compound having a heterocyclic skeleton represented by formula (b0) has a higher external quantum efficiency than the light-emitting device of this embodiment. Therefore, the low molecular weight compound having a heterocyclic skeleton represented by formula (b0-2-1) to formula (b0-2-4) (i.e., the heterocyclic skeleton represented by formula (b0) is a low molecular weight compound having a heterocyclic skeleton represented by formula (b0-2-1) to formula (b0-2-4)) (heterocyclic skeleton represented by formula (b0-2-1) or (b0-2-3)), more preferably a low molecular weight compound having a heterocyclic skeleton represented by formula (b0-2-1) or (b0-2-3) (i.e., the heterocyclic skeleton represented by formula (b0) is a heterocyclic skeleton represented by formula (b0-2-1) or (b0-2-3)), and even more preferably a low molecular weight compound having a heterocyclic skeleton represented by formula (b0-2-1) (i.e., the heterocyclic skeleton represented by formula (b0) is a heterocyclic skeleton represented by formula (b0-2-1)).

[0133] [ka] [In the formula, Ar b1 , Ar b2 , Ar b3 and X b2 represents the same meaning as above. Ar xb1 and Ar xb2 each independently represents an aromatic hydrocarbon group or a heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. X xb1 , X xb2 and X xb3 are each independently a direct bond, an oxygen atom, a sulfur atom, a selenium atom, or -N(R xb )-, -B(R xb )-, an alkylene group, or a cycloalkylene group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. R xb represents the same meaning as above. X xb1 and Ar xb1 , X xb1 and Ar b2 , X xb2 and Ar xb1 , X xb2 and Ar b1 , X xb3 and Ar xb2 , and X xb3 and Ar b3 may each independently bond directly or via a divalent or higher valent group which may have a substituent to form a ring, and in formula (b0-2-1) and formula (b0-2-3), Ar b1 and Ar xb1 may be bonded directly or via a divalent or higher valent group which may have a substituent to form a ring, and in formula (b0-2-2) and formula (b0-2-4), Ar b2 and Ar xb1 may be bonded directly or via a divalent or higher valent group which may have a substituent to form a ring, and in formula (b0-2-3) and formula (b0-2-4), Ar b1 and Ar xb2 may be bonded directly or via a divalent or higher group which may have a substituent to form a ring. When there are multiple substituents in the divalent or higher group, they may be the same or different and may be bonded to each other to form a ring together with the atom to which they are bonded.

[0134] Ar xb1 and Ar xb2 Examples and preferred ranges of Ar b , Ar b4 and Ar b5 The examples and preferred ranges are the same as those of the above.

[0135] In formulas (b0-1-1) to (b0-1-3), Ar b1 , Ar b2 and Ar b3 is other than the heterocyclic group (b'), Ar b1 , Ar b2 and Arb3 Examples and preferred ranges of Ar b , Ar b4 and Ar b5 The examples and preferred ranges are the same as those of the above.

[0136] X xb1 , X xb2 and X xb3 is preferably a direct bond, an oxygen atom, a sulfur atom, a selenium atom, or —N(R xb )- or -B(R xb )-, and more preferably a direct bond, an oxygen atom, a sulfur atom, or —N(R xb )- or -B(R xb )- is a group represented by More preferably, a direct bond, an oxygen atom, or —N(R xb )- or -B(R xb )-, and particularly preferably, -N(R xb )- or -B(R xb )-, and particularly preferably -B(R xb )-, and these groups may have a substituent. X xb1 , X xb2 and X xb3 Examples of the substituents that may be possessed by X and the preferred range thereof are as follows: b1 and X b2 The examples and preferred ranges of the substituents that may be possessed by the group are the same as those of the substituents that may be possessed by the group.

[0137] Examples and preferred ranges of the divalent or higher valent groups which may have a substituent in formulas (b0-2-1) to (b0-2-4) are the same as the examples and preferred ranges of the divalent or higher valent groups which may have a substituent described in the section when formula (b0) satisfies requirement (b0-ii).

[0138] The low molecular weight compound (b) is preferably a low molecular weight compound having a heterocyclic skeleton represented by formula (b0-1-1) to formula (b0-1-3) or formula (b0-2-1) to formula (b0-2-4), more preferably a low molecular weight compound having a heterocyclic skeleton represented by formula (b0-1-1), formula (b0-1-2), formula (b0-2-1) or formula (b0-2-3), even more preferably a low molecular weight compound having a heterocyclic skeleton represented by formula (b0-1-1), formula (b0-2-1) or formula (b0-2-3), and particularly preferably a low molecular weight compound having a heterocyclic skeleton represented by formula (b0-1-1).

[0139] The low molecular weight compound having a heterocyclic skeleton represented by formula (b0) preferably satisfies at least one of requirement (i) and requirement (ii), and more preferably satisfies both requirement (i) and requirement (ii), since the external quantum efficiency of the light-emitting device of this embodiment is superior.

[0140] When the low molecular weight compound (b) satisfies the requirement (i), the external quantum efficiency of the light-emitting device of this embodiment is superior. Therefore, the low molecular weight compound (b) is preferably a low molecular weight compound having a heterocyclic skeleton represented by formula (b0-1-1) to formula (b0-1-3), formula (b0-2-3) or formula (b0-2-4), more preferably a low molecular weight compound having a heterocyclic skeleton represented by formula (b0-1-1) to formula (b0-1-3), even more preferably a low molecular weight compound having a heterocyclic skeleton represented by formula (b0-1-1) or formula (b0-1-2), and particularly preferably a low molecular weight compound having a heterocyclic skeleton represented by formula (b0-1-1).

[0141] When the low molecular weight compound (b) satisfies the requirement (ii), the external quantum efficiency of the light-emitting device of this embodiment is superior. b1 , X b2 , X b3 and X b4 At least two of the following are -N(R xbWhen the low molecular weight compound (b) satisfies the requirement (ii), X in formula (b0-1-3) is preferably a group represented by the formula (b0-1-3). b1 , X b2 , X b3 and X b5 At least two of the following are -N(R xb When the low molecular weight compound (b) satisfies the requirement (ii), X in formula (b0-2-1) is preferably a group represented by the formula (b0-2-2). xb1 and X b2 At least one of -N(R xb When the low molecular weight compound (b) satisfies the requirement (ii), X in the formula (b0-2-2) is preferably a group represented by the formula (b0-2-3). xb2 and X b2 At least one of -N(R xb )- is preferably a group represented by the formula:

[0142] When the low molecular weight compound (b) satisfies the requirements (i) and (ii), the external quantum efficiency of the light-emitting device of this embodiment is superior. Therefore, the low molecular weight compound (b) is preferably a low molecular weight compound having a heterocyclic skeleton represented by formula (b0-1-1) or formula (b0-1-2), and in formula (b0-1-1) and formula (b0-1-2), X b1 , X b2 , X b3 and X b4 At least two of the following are -N(R xb )-, and is a low molecular weight compound having a heterocyclic skeleton represented by formula (b0-1-1) and (b0-1-1) Medium, X b1 , X b2 , X b3 and X b4 At least two of the following are -N(R xb It is more preferable that the compound is a low molecular weight compound represented by the group represented by the formula (I).

[0143] A low molecular weight compound having a heterocyclic skeleton represented by formula (b0-1-1), wherein X b1 , X b2 , X b3 and Xb4 At least two of the following are -N(R xb The low molecular weight compound which is a group represented by formula (b0-1-1′)- may be, for example, a low molecular weight compound having a heterocyclic skeleton represented by formula (b0-1-1′).

[0144] [ka] [In the formula, Ar b , Ar b1 , Ar b3 , Ar xb1 , Ar b4 , Ar b5 , X b2 , X b4 and X b0-1 represents the same meaning as above. Ar xb3 represents an aromatic hydrocarbon group or a heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. Ar b1 and Ar xb1 , Ar xb1 and Ar xb3 , and Ar xb3 and Ar b4 may each independently bond directly or via a divalent or higher group which may have a substituent to form a ring. When there are multiple substituents in the divalent or higher group, they may be the same or different and may bond to each other to form a ring together with the atom to which they are bonded.

[0145] Ar xb3 Examples and preferred ranges of Ar xb1 and Ar xb2 The examples and preferred ranges are the same as those of the above.

[0146] Examples and preferred ranges of the divalent or higher group which may have a substituent in formula (b0-1-1') are the same as the examples and preferred ranges of the divalent or higher group which may have a substituent described in the section when formula (b0) satisfies requirement (b0-ii).

[0147] (Low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1)) As described above, the low molecular weight compound (b) preferably satisfies the requirement (i) and is more preferably a low molecular weight compound having a heterocyclic skeleton represented by formula (b0-1-1). However, since the external quantum efficiency of the light-emitting element of this embodiment is further improved, it is even more preferably a low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1). As described above, it is preferable that the low molecular weight compound (b) further satisfies the requirement (ii), and the external quantum efficiency of the light-emitting device of this embodiment is further improved. b1 , X b2 , X b3 and X b4 At least two of the following are -N(R xb )- is preferably a group represented by the formula:

[0148] Ring R in formula (b1-1) b1 , ring R b2 and ring R b3 Examples and preferred ranges of the aromatic hydrocarbon ring and heterocyclic ring in Ar b1 , Ar b2 and Ar b3 The examples and preferred ranges of the aromatic hydrocarbon ring and heterocyclic ring are the same as those explained in the section on aromatic hydrocarbon groups and heterocyclic groups in the above. Ring R in formula (b1-1) b4 and ring R b5 Examples and preferred ranges of the aromatic hydrocarbon ring and heterocyclic ring in Ar b4 and Ar b5 The examples and preferred ranges of the aromatic hydrocarbon ring and heterocyclic ring are the same as those explained in the section on aromatic hydrocarbon groups and heterocyclic groups in the above. Ring R b1 , ring R b2 , ring R b3 , ring R b4and ring R b5 Examples of the substituents that may be possessed by Ar and the preferred ranges thereof are as follows: b1 , Ar b2 and Ar b3 The examples and preferred ranges of the substituents that may be possessed by the group are the same as those of the substituents that may be possessed by the group. Ring R b1 , ring R b2 , ring R b3 , ring R b4 and ring R b5 Since it has one or more bonds, the ring R b1 , ring R b2 , ring R b3 , ring R b4 and ring R b5 The aromatic hydrocarbon ring and heterocyclic ring in the formula (I) can also be referred to as an aromatic hydrocarbon group and a heterocyclic group, respectively.

[0149] Therefore, the ring R b1 , ring R b2 , ring R b3 , ring R b4 and ring R b5 Examples and preferred ranges of Ar in formula (b1-1) are b1 , Ar b , Ar b3 , Ar b4 and Ar b5 Similarly, the examples and preferred ranges of X in formula (b1-1) can be applied. b1 , X b2 , X b3 and X b4 The examples and preferred ranges of X are described in the section on formula (b0). b1 , X b2 , X b3 and X b4 Similarly, the examples and preferred ranges of the divalent or more optionally substituted group in formula (b1-1) are the same as the examples and preferred ranges of the divalent or more optionally substituted group described in the section on the case where formula (b0) satisfies requirement (b0-ii).

[0150] Ring R b1 , ring R b2 , ring R b3 , ring Rb4 and ring R b5 is preferably an aromatic hydrocarbon ring, more preferably a monocyclic aromatic hydrocarbon ring, and even more preferably a benzene ring, since the external quantum efficiency of the light-emitting element of this embodiment is superior, and these rings may have a substituent.

[0151] As described above in the section on the low molecular weight compound (b), the low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1) has a higher external quantum efficiency of the light-emitting device of this embodiment, and therefore, the sp 3 The total number of carbon atoms is preferably 9 or more. Furthermore, since the low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1) provides a light-emitting device of this embodiment with a superior external quantum efficiency, it is preferable that the low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1) has at least one selected from the group consisting of an aryl group having three or more substituents and a monovalent heterocyclic group having three or more substituents. Since ... 3 It is preferable that the low molecular weight compound having a total of 9 or more carbon atoms and a heterocyclic skeleton represented by formula (b1-1) has at least one selected from the group consisting of an aryl group having three or more substituents and a monovalent heterocyclic group having three or more substituents.

[0152] The low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1) may be, for example, a low molecular weight compound having a heterocyclic skeleton represented by formula (b1-2-0).

[0153] [ka] [In the formula, Ring R b1 , ring R b2 , ring R b3 , ring R b4 , ring Rb5 , X b2 , X b4 and X b0-1 represents the same meaning as above. Ring R Xb1 and ring R Xb2 each independently represents an aromatic hydrocarbon ring or a heterocyclic ring, and these rings may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. Ring R Xb1 and ring R b1 , ring R Xb1 and ring R Xb2 , and ring R Xb2 and ring R b4 may each independently bond directly or via a divalent or higher group which may have a substituent to form a ring. When there are multiple substituents in the divalent or higher group, they may be the same or different and may bond to each other to form a ring together with the atom to which they are bonded.

[0154] Ring R Xb1 and ring R Xb2 Examples and preferred ranges of ring R b1 , ring R b2 , ring R b3 , ring R b4 and ring R b5 The examples and preferred ranges are the same as those of the above. Examples and preferred ranges of the optionally substituted divalent or higher valent group in formula (b1-2-0) are the same as the examples and preferred ranges of the optionally substituted divalent or higher valent group in formula (b1-1).

[0155] The low molecular weight compound having a heterocyclic skeleton represented by formula (b1-2-0) is preferable because it provides the light-emitting device of this embodiment with even better external quantum efficiency.

[0156] [ka] [In the formula, ring R b1 , ring R b2 , ring R b3 , ring R b4 , ring R b5 , X b2 , X b4 , ring R Xb1 and ring R Xb2 has the same meaning as above.]

[0157] (Low molecular weight compound represented by formula (b1-1')) As described above in the section on the low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1), the external quantum efficiency of the light-emitting device of this embodiment is superior. Therefore, the sp 3 Preferably, the total number of carbon atoms is 9 or more, or the low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1) has at least one selected from the group consisting of an aryl group having three or more substituents and a monovalent heterocyclic group having three or more substituents. That is, the low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1) is preferably a low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1').

[0158] In the low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1'), the sp 3 The total number of carbon atoms is 9 or more, or the low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1') has at least one selected from the group consisting of an aryl group having three or more substituents and a monovalent heterocyclic group having three or more substituents. Examples and preferred ranges of these are the same as the examples and preferred ranges described above in the section on low molecular weight compound (b). The low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1') may be, for example, a low molecular weight compound having a heterocyclic skeleton represented by formula (b1-2').

[0159] [ka] [In the formula, ring R b1 , ring R b2 , ring R b3 , ring R b4 , ring R b5 , X b2 , X b4 , ring R Xb1 and ring R Xb2 has the same meaning as above.]

[0160] Examples of the low molecular weight compound (b) include low molecular weight compounds represented by the following formula: 1 represents an oxygen atom or a sulfur atom. 1 When a plurality of Z are present, they may be the same or different. 2 represents a group represented by -CH= or -N=. Z 2 When there are multiple Z's, they may be the same or different. 3 represents a hydrogen atom or an alkyl group. 3 When there are multiple groups, they may be the same or different.

[0161] [ka]

[0162] [ka]

[0163] [ka]

[0164] [ka]

[0165] [ka]

[0166] [High molecular compound (B)] The polymer compound (B) of this embodiment is a polymer compound that includes a structural unit (b) having a group in which one or more hydrogen atoms have been removed from the low molecular weight compound (b). The structural unit (b) is preferably a structural unit having a group in which one or more hydrogen atoms have been removed from a low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1'), since this results in a more excellent external quantum efficiency of the light-emitting element of this embodiment. That is, the polymer compound (B) of this embodiment is preferably a polymer compound containing a structural unit having a group in which one or more hydrogen atoms have been removed from a low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1'). The structural unit (b) is preferably a structural unit having a group obtained by removing 1 to 5 hydrogen atoms from the low molecular weight compound (b), since this facilitates the synthesis of the polymer compound (B), more preferably a structural unit having a group obtained by removing 1 to 3 hydrogen atoms from the low molecular weight compound (b), even more preferably a structural unit having a group obtained by removing 1 or 2 hydrogen atoms from the low molecular weight compound (b), and particularly preferably a structural unit having a group obtained by removing 2 hydrogen atoms from the low molecular weight compound (b).

[0167] (Constituent units represented by formula (BP-1), formula (BP-2) or formula (BP-3)) The structural unit (b) is preferably a structural unit represented by formula (BP-1), formula (BP-2) or formula (BP-3), more preferably a structural unit represented by formula (BP-1) or formula (BP-2), and even more preferably a structural unit represented by formula (BP-2), because the synthesis of the polymer compound (B) is easy and the external quantum efficiency of the light-emitting device of this embodiment is superior. L BP1 is preferably an alkylene group, a cycloalkylene group, an arylene group, or a divalent heterocyclic group, more preferably an alkylene group or an arylene group, and even more preferably an arylene group, since the external quantum efficiency of the light-emitting element of this embodiment is more excellent. These groups may have a substituent.

[0168] L BP1Examples and preferred ranges of the arylene group and the divalent heterocyclic group in Y1 The examples and preferred ranges of the arylene group and divalent heterocyclic group are the same as those in the above. L BP1 The alkylene group in is preferably a methylene group, ethylene group, propylene group, butylene group, pentylene group, or hexylene group, more preferably a methylene group, ethylene group, or propylene group, and even more preferably a methylene group, and these groups may have a substituent.

[0169] L BP1 The cycloalkylene group in the formula (I) is preferably a cyclopropylene group, a cyclobutylene group, a cyclopentylene group or a cyclohexylene group, more preferably a cyclohexylene group, and these groups may have a substituent. R BP1 Examples and preferred ranges of R X1 ~R X3 The examples and preferred ranges are the same as those of the above.

[0170] n BP1 is preferably an integer of 0 to 5, preferably an integer of 0 to 3, more preferably 0 or 1, and even more preferably 0.

[0171] Ar BP1 is preferably an alkylene group, a cycloalkylene group, an arylene group, or a divalent heterocyclic group, more preferably an alkylene group or an arylene group, and even more preferably an arylene group, since the external quantum efficiency of the light-emitting element of this embodiment is more excellent. These groups may have a substituent.

[0172] Ar BP1 Examples of the hydrocarbon group in Ar include aromatic hydrocarbon groups and aliphatic hydrocarbon groups, and aromatic hydrocarbon groups are preferred because they provide a more excellent external quantum efficiency for the light-emitting device of this embodiment, and these groups may have a substituent. BP1 The hydrocarbon group in the formula (I) includes groups in which a plurality of these groups are bonded.

[0173] Ar BP1 In the above, the aliphatic hydrocarbon group is an alkylene group or a cycloalkylene group to which a hydrogen atom n BP1 Preferably, the alkylene group is a group obtained by removing n hydrogen atoms. BP1 These groups may have a substituent. BP1 Examples and preferred ranges of the alkylene group and cycloalkylene group in the group excluding the above groups are, respectively, L BP1 Examples of the alkylene group and the cycloalkylene group and preferred ranges thereof are as follows:

[0174] Ar BP1 In the above, the aromatic hydrocarbon group is a group having n hydrogen atoms from an arylene group. BP1 The arylene group may have a substituent. BP1 Examples of the arylene group in the group excluding the above and a preferred range thereof are Ar Y1 Examples of the arylene group and preferred ranges thereof are as follows:

[0175] Ar BP1 As the heterocyclic group in BP1 The group may have a substituent. BP1 Examples and preferred ranges of the divalent heterocyclic group in the group excluding the above are as follows: Ar Y1 Examples of the divalent heterocyclic group and preferred ranges thereof are as follows: L BP1 and Ar BP1 Examples of the substituents that may be possessed by Ar Y1 The examples and preferred ranges of the substituents that may be possessed by the group represented by the formula:

[0176] Examples of the structural unit (b) include M in formula (BP-1): BP1 , M in formula (BP-2) BP2, and M in formula (BP-3) BP3 The low molecular weight compound (b) in the formula (1) includes a structural unit that is a low molecular weight compound exemplified in the section on low molecular weight compound (b) above, as well as a structural unit derived from compounds BM1 to BM4 described below, and examples thereof include structural units represented by the following formula: 1 and Z 3 represents the same meaning as above.

[0177] [ka]

[0178] [ka]

[0179] [ka]

[0180] The content of the structural unit (b) contained in the polymer compound (B) may be within a range that allows the polymer compound (B) to function as intended. The content of the structural unit (b) contained in the polymer compound (B) relative to the total content of the structural units contained in the polymer compound (B) may be, for example, 0.01 to 100 mol%, 0.02 to 99 mol%, or 0.03 to 90 mol%, and is preferably 0.05 to 70 mol%, more preferably 0.1 to 50 mol%, even more preferably 0.2 to 30 mol%, particularly preferably 0.3 to 10 mol%, and especially preferably 0.5 to 5 mol%, based on which the external quantum efficiency of the light-emitting device of this embodiment is further improved. The polymer compound (B) may contain only one type of structural unit (b), or two or more types of structural unit (b).

[0181] The polymer compound (B) preferably further contains at least one structural unit selected from the group consisting of structural units represented by formula (X) and structural units represented by formula (Y), because this provides the light-emitting device of this embodiment with better external quantum efficiency. That is, the polymer compound (B) is preferably a polymer compound containing at least one structural unit selected from the group consisting of structural units represented by formula (X) and structural units represented by formula (Y), and structural unit (b). When the polymer compound (B) contains at least one structural unit selected from the group consisting of structural units represented by formula (X) and structural units represented by formula (Y), the structural unit (B) is preferably different from the structural unit represented by formula (X) described below and the structural unit represented by formula (Y) described below, and it is more preferable that the structural unit represented by formula (X) and the structural unit represented by formula (Y) do not contain a group in which one or more hydrogen atoms have been removed from the low molecular weight compound (b) having a heterocyclic skeleton (b). The polymer compound (B) preferably further comprises a structural unit represented by formula (Y), since this provides a superior external quantum efficiency for the light-emitting device of this embodiment. The polymer compound (B) preferably further comprises a structural unit represented by formula (X), since this provides a superior hole-transporting property for the polymer compound (B). The polymer compound (B) preferably further comprises a structural unit represented by formula (X) and a structural unit represented by formula (Y), since this provides a superior hole-transporting property for the polymer compound (B) and the light-emitting device of this embodiment has a superior external quantum efficiency.

[0182] When the polymer compound (B) contains a structural unit represented by formula (X), the content of the structural unit represented by formula (X) may be within a range that allows the polymer compound (B) to function. When the polymer compound (B) contains a structural unit represented by formula (X), the content of the structural unit represented by formula (X) relative to the total content of the structural units contained in the polymer compound (B) may be, for example, It may be 0.01 to 99.99 mol %, or 0.02 to 99 mol %, and is preferably 0.05 to 90 mol %, more preferably 0.1 to 70 mol %, even more preferably 0.2 to 50 mol %, particularly preferably 0.5 to 30 mol %, and especially preferably 1 to 10 mol %, since the hole transport property of the polymer compound (B) is excellent and the external quantum efficiency of the light-emitting element of this embodiment is further excellent. The polymer compound (B) may contain only one type of constitutional unit represented by formula (X), or may contain two or more types.

[0183] When the polymer compound (B) contains a structural unit represented by formula (Y), the content of the structural unit represented by formula (Y) may be within a range that allows the polymer compound (B) to function as intended. When the polymer compound (B) contains a structural unit represented by formula (Y), the content of the structural unit represented by formula (Y) relative to the total content of structural units contained in the polymer compound (B) may be, for example, 0.01 to 99.99 mol%, 0.1 to 99.98 mol%, or 1 to 99.97 mol%, and is preferably 10 to 99.95 mol%, more preferably 30 to 99.9 mol%, even more preferably 50 to 99.8 mol%, particularly preferably 70 to 99.5 mol%, and particularly preferably 90 to 99 mol%, relative to the total content of structural units contained in the polymer compound (B). In order to achieve a superior external quantum efficiency of the light-emitting device of this embodiment, the content of the structural unit represented by formula (Y) is preferably 10 to 99.95 mol%, more preferably 30 to 99.9 mol%, even more preferably 50 to 99.8 mol%, particularly preferably 70 to 99.5 mol%, and especially preferably 90 to 99 mol%. The polymer compound (B) may contain only one type of constitutional unit represented by formula (Y), or may contain two or more types.

[0184] When the polymer compound (B) contains a structural unit represented by formula (X) and / or a structural unit represented by formula (Y), and structural unit (b), the total content of the structural unit represented by formula (X), the structural unit represented by formula (Y), and structural unit (b) may be within a range that allows the polymer compound (B) to function. When the polymer compound (B) contains a structural unit represented by formula (X) and / or a structural unit represented by formula (Y), and structural unit (b), the total content of the structural unit represented by formula (X), the structural unit represented by formula (Y), and structural unit (B) is, for example, 1 to 100 mol%, based on the total content of the structural units contained in the polymer compound (B). In order to achieve superior external quantum efficiency of the light-emitting device of this embodiment, the total content of the structural unit represented by formula (X), the structural unit represented by formula (Y), and structural unit (B) is preferably 10 to 100 mol%, more preferably 30 to 100 mol%, even more preferably 50 to 100 mol%, particularly preferably 70 to 100 mol%, and particularly preferably 90 to 100 mol%.

[0185] (Constituent unit represented by formula (Y)) Ar Y1 The arylene group represented by the formula (I) is preferably a group obtained by removing two hydrogen atoms directly bonded to atoms constituting the ring from a monocyclic or bicyclic to hexacyclic aromatic hydrocarbon ring, since the external quantum efficiency of the light-emitting element of this embodiment is more excellent; more preferably a group obtained by removing two hydrogen atoms directly bonded to atoms constituting the ring from a monocyclic, bicyclic or tricyclic aromatic hydrocarbon ring; even more preferably a group obtained by removing two hydrogen atoms directly bonded to atoms constituting the ring from benzene, naphthalene, anthracene, phenanthrene, dihydrophenanthrene, dibenzocycloheptane or fluorene; particularly preferably a group obtained by removing two hydrogen atoms directly bonded to atoms constituting the ring from benzene, phenanthrene, dihydrophenanthrene or fluorene; and particularly preferably a group obtained by removing two hydrogen atoms directly bonded to atoms constituting the ring from benzene or fluorene, and these groups may have a substituent.

[0186] Ar Y1The divalent heterocyclic group represented by the formula (I) is preferably a group in which two hydrogen atoms directly bonded to atoms constituting the ring are removed from a monocyclic or bicyclic to hexacyclic heterocycle, more preferably a group in which two hydrogen atoms directly bonded to atoms constituting the ring are removed from a monocyclic, bicyclic or tricyclic heterocycle, and even more preferably pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene , carbazole, dibenzofuran, dibenzothiophene, phenoxazine, phenothiazine, 9,10-dihydroacridine, or 5,10-dihydrophenazine, by removing two hydrogen atoms directly bonded to an atom constituting the ring (preferably a carbon atom or a nitrogen atom, more preferably a carbon atom), and particularly preferably a group obtained by removing two hydrogen atoms directly bonded to an atom constituting the ring (preferably a carbon atom or a nitrogen atom, more preferably a carbon atom) from pyridine, diazabenzene, triazine, carbazole, dibenzofuran, dibenzothiophene, phenoxazine, or phenothiazine, and particularly preferably a group obtained by removing two hydrogen atoms directly bonded to an atom constituting the ring (preferably a carbon atom or a nitrogen atom, more preferably a carbon atom) from pyridine, diazabenzene, triazine, carbazole, dibenzofuran, or dibenzothiophene, and these groups may have a substituent. Ar Y1 In the divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded, the preferred ranges of the arylene group and the divalent heterocyclic group are, respectively, Ar Y1 The preferred ranges are the same as those of the arylene group and divalent heterocyclic group represented by the following formula:

[0187] Ar Y1 In the above, examples of the "divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded" include groups represented by the following formulae, and these groups may have a substituent.

[0188] [ka]

[0189] Ar Y1 is preferably an arylene group which may have a substituent, since the external quantum efficiency of the light-emitting device of this embodiment is superior.

[0190] Ar Y1 The substituent that the group represented by the formula (I) may have is preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a monovalent heterocyclic group, a substituted amino group, or a fluorine atom, since this provides a more excellent external quantum efficiency for the light-emitting element of this embodiment, more preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group, or a substituted amino group, even more preferably an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group, or a substituted amino group, and particularly preferably an alkyl group, a cycloalkyl group, or an aryl group, and these groups may further have a substituent. Ar Y1 The aryl group in the substituent that the group represented by the formula (I) may have is preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from a monocyclic or bicyclic to hexacyclic aromatic hydrocarbon ring, more preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from a monocyclic, bicyclic or tricyclic aromatic hydrocarbon ring, still more preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from benzene, naphthalene, anthracene, phenanthrene, dihydrophenanthrene, dibenzocycloheptane or fluorene, particularly preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from benzene, phenanthrene, dihydrophenanthrene or fluorene, and particularly preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from fluorene. These groups may further have a substituent. Ar Y1The monovalent heterocyclic group in the substituent that may be included in the group represented by the formula (I) is preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from a monocyclic or bicyclic to hexacyclic heterocycle, more preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from a monocyclic, bicyclic or tricyclic heterocycle, and even more preferably pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, carbazole, dibenzofuran, dibenzothiophene, phenoxazine, phenothiazine, 9,10-dihydroacridine or 5,10 -a group obtained by removing, from dihydrophenazine, one hydrogen atom that is directly bonded to an atom that constitutes the ring (preferably a carbon atom or a nitrogen atom); particularly preferred is a group obtained by removing, from pyridine, diazabenzene, triazine, carbazole, dibenzofuran, dibenzothiophene, phenoxazine, or phenothiazine, one hydrogen atom that is directly bonded to an atom that constitutes the ring (preferably a carbon atom or a nitrogen atom); particularly preferred is a group obtained by removing, from pyridine, diazabenzene, or triazine, one hydrogen atom that is directly bonded to an atom that constitutes the ring (preferably a carbon atom); and these groups may further have a substituent. Ar Y1 In the substituted amino group in the substituent that the group represented by the formula (I) may have, the substituent that the amino group has is preferably an aryl group or a monovalent heterocyclic group, more preferably an aryl group, and these groups may further have a substituent. Examples and preferred ranges of the aryl group and the monovalent heterocyclic group in the substituent that the amino group has are respectively given as Ar Y1 The examples and preferred ranges of the aryl group and monovalent heterocyclic group in the substituent that may be possessed by the group represented by the following formula are the same as those of the aryl group and monovalent heterocyclic group.

[0191] Ar Y1The substituent that the group represented by the formula (I) may further have is preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a monovalent heterocyclic group, a substituted amino group, or a fluorine atom, because the external quantum efficiency of the light-emitting element of this embodiment is more excellent. More preferably, it is an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group, or a substituted amino group. Even more preferably, it is an alkyl group, a cycloalkyl group, or an aryl group. Particularly preferably, it is an alkyl group or a cycloalkyl group. These groups may further have a substituent, but it is preferable that they do not further have a substituent. Ar Y1 Examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in the substituent that may be further substituted by the substituent that may be substituted by the group represented by the formula: Y1 The examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in the substituent that the group represented by the following formula may have are the same as those of the aryl group, monovalent heterocyclic group and substituted amino group in the substituent that the group represented by the following formula may have.

[0192] The structural unit represented by formula (Y) is preferably a structural unit represented by formula (Y-1) to formula (Y-9), and more preferably a structural unit represented by formula (Y-1), formula (Y-3), formula (Y-5), formula (Y-6) or formula (Y-7), since the external quantum efficiency of the light-emitting device of this embodiment is more excellent.

[0193] [ka]

[0194] [ka]

[0195] [ka]

[0196] [ka] [In the formula, X Y1 is -C(R Y2 )2-, -C(R Y2 )=C(R Y2 )-, -C(R Y2 )2-C(R Y2 )2-, -C(R Y1 )2-C(R Y1 )2-C(R Y1 )2-, -O-, -S-, or -N(R Y4 )-. R Y1 , R Y2 , R Y3 and R Y4 are each independently a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a monovalent heterocyclic group, a substituted amino group, or a fluorine atom, and these groups may have a substituent. When there are multiple such substituents, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. When there are multiple R Y1 , multiple R Y2 They may be the same or different and may be bonded to each other to form a ring together with the carbon atoms to which they are bonded.

[0197] R Y1 is preferably a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group, or a substituted amino group, since this results in a more excellent external quantum efficiency of the light-emitting element of this embodiment; more preferably a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group; even more preferably a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group; and particularly preferably a hydrogen atom or an alkyl group, and these groups may have a substituent.

[0198] R Y2is preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group, or a substituted amino group, since the external quantum efficiency of the light-emitting element of this embodiment is more excellent; more preferably an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group; and even more preferably an alkyl group, a cycloalkyl group, or an aryl group, and these groups may have a substituent.

[0199] R Y3 is preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group, or a substituted amino group, since the external quantum efficiency of the light-emitting element of this embodiment is superior, more preferably an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, even more preferably an aryl group or a monovalent heterocyclic group, and particularly preferably an aryl group, and these groups may have a substituent.

[0200] R Y4 is preferably a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, since the external quantum efficiency of the light-emitting element of this embodiment is superior, more preferably an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, even more preferably an aryl group or a monovalent heterocyclic group, and particularly preferably an aryl group, and these groups may have a substituent.

[0201] R Y1 , R Y2 , R Y3 and R Y4 Examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in Y1 The examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in the substituent that the group represented by the following formula may have are the same as those of the aryl group, monovalent heterocyclic group and substituted amino group in the substituent that the group represented by the following formula may have. R Y1 , R Y2 , R Y3 and R Y4 Examples of the substituents that may be possessed by Ar and the preferred ranges thereof are as follows: Y1The examples and preferred ranges of the substituents that may be possessed by the group represented by the formula:

[0202] X Y1 is preferably -C(R Y2 )2-, -C(R Y2 )2-C(R Y2 )2-, -C(R Y1 )2-C(R Y1 )2-C(R Y1 )2-, -O-, or -S-, and -C(R Y2 )2-, -C(R Y2 )2-C(R Y2 )2-, -O-, -S-, or -N(R Y4 )-, and more preferably, -C(R Y2 )2-, -O-, or -S-, and particularly preferably -C(R Y2 )2- or -S-.

[0203] Examples of the constitutional unit represented by formula (Y) include constitutional units represented by the following formula:

[0204] [ka]

[0205] [ka]

[0206] [ka]

[0207] [ka]

[0208] [ka]

[0209] [ka]

[0210] [ka]

[0211] [ka]

[0212] [ka]

[0213] [ka]

[0214] [ka]

[0215] [ka]

[0216] [ka]

[0217] [ka]

[0218] (Constituent unit represented by formula (X)) a X1 and a X2is usually an integer of 0 to 10, and is preferably an integer of 0 to 5, more preferably an integer of 0 to 3, even more preferably an integer of 0 to 2, and particularly preferably 0 or 1, since the external quantum efficiency of the light-emitting device of this embodiment is more excellent.

[0219] R X1 , R X2 and R X3 is preferably an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, more preferably an aryl group or a monovalent heterocyclic group, and even more preferably an aryl group, since the external quantum efficiency of the light-emitting element of this embodiment is superior. These groups may have a substituent. R X1 , R X2 and R X3 Examples and preferred ranges of the aryl group and the monovalent heterocyclic group in Y1 The examples and preferred ranges of the aryl group and monovalent heterocyclic group in the substituent that may be possessed by the group represented by the following formula are the same as those of the aryl group and monovalent heterocyclic group.

[0220] Ar X1 , Ar X2 , Ar X3 and Ar X4 is preferably an arylene group which may have a substituent, since the external quantum efficiency of the light-emitting device of this embodiment is superior. Ar X1 , Ar X2 , Ar X3 and Ar X4 Examples and preferred ranges of the arylene group and the divalent heterocyclic group in Y1 The examples and preferred ranges of the arylene group and divalent heterocyclic group are the same as those in the above. Ar X2 and Ar X4 In the divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded, examples and preferred ranges of the arylene group and the divalent heterocyclic group are respectively Ar Y1 The examples and preferred ranges of the arylene group and divalent heterocyclic group are the same as those in the above. ArX2 and Ar X4 In the above, examples of the divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded include Ar Y1 Examples of the divalent group include the same as the divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded to each other in the above formula.

[0221] Ar X1 ~Ar X4 and R X1 ~R X3 Examples of the substituents that the group represented by the formula (I) may have and their preferred ranges are: Y1 The examples and preferred ranges of the substituents that may be possessed by the group represented by the formula:

[0222] Examples of the constitutional unit represented by formula (X) include constitutional units represented by the following formula:

[0223] [ka]

[0224] [ka]

[0225] [ka]

[0226] [ka]

[0227] [ka]

[0228] [ka]

[0229] [ka]

[0230] Examples of polymer compound (B) include polymer compounds BP-1 to BP-4. Here, "other" refers to structural units other than the structural unit (B), the structural unit represented by formula (X), and the structural unit represented by formula (Y).

[0231] [Table 1] [In the table, p b , q b , r b and s b represents the molar ratio (mol%) of each structural unit. b +q b +r b +s b = 100 and 70≦p b +q b +r b ≦100.]

[0232] The polymer compound (B) may be a block copolymer, a random copolymer, an alternating copolymer, a graft copolymer, or other form, but is preferably a copolymer obtained by copolymerizing multiple types of raw material monomers. Since the external quantum efficiency of the light-emitting device of this embodiment is superior, the number average molecular weight of the polymer compound (B) in terms of polystyrene is preferably 1×10 3 ~1×10 6 and more preferably is 2 x 10 3 ~5×10 5 and more preferably 4×10 3 ~1×10 5 Since the external quantum efficiency of the light-emitting device of this embodiment is superior, the weight average molecular weight of the polymer compound (B) in terms of polystyrene is preferably 2×10 3 ~2×10 6 and more preferably 5×103 ~1×10 6 and more preferably 1 × 10 4 ~5×10 5 is.

[0233] The maximum peak wavelength of the emission spectrum of the polymer compound (B) at 25°C is preferably 380 nm or more, more preferably 400 nm or more, even more preferably 420 nm or more, particularly preferably 440 nm or more, and may be 460 nm or more. The maximum peak wavelength of the emission spectrum of the polymer compound (B) at 25°C is preferably 750 nm or less, more preferably 620 nm or less, even more preferably 570 nm or less, and may be 540 nm or less, 520 nm or less, or 500 nm or less. The half width of the maximum peak of the emission spectrum of the polymer compound (B) at 25°C may be 1 nm or more, 3 nm or more, 5 nm or more, 7 nm or more, or 10 nm or more. The half width of the maximum peak of the emission spectrum of the polymer compound (B) at 25°C is preferably 60 nm or less, more preferably 40 nm or less, even more preferably 35 nm or less, particularly preferably 30 nm or less, especially preferably 20 nm or less, especially more preferably 18 nm or less, especially more preferably 17 nm or less, and especially especially preferably 16 nm or less. The maximum peak wavelength of the emission spectrum of a polymer compound at room temperature can be evaluated by measuring the PL spectrum of a film of the polymer compound at room temperature. A film of the polymer compound can be prepared by the same method as the film preparation method described in the <Film> section below. In preparing a film of the polymer compound, spin coating is a preferred wet method. Furthermore, in preparing a film of the polymer compound, xylene is a preferred solvent for dissolving the polymer compound.

[0234] (Method for producing polymer compound (B)) The polymer compound (B) can be produced by a known polymerization method described in, for example, Chem. Rev., Vol. 109, pp. 897-1091 (2009), and examples of such methods include polymerization by coupling reactions using transition metal catalysts, such as Suzuki reaction, Yamamoto reaction, Buchwald reaction, Stille reaction, Negishi reaction, and Kumada reaction. In the above polymerization method, examples of the method for charging the monomers include a method in which the entire amount of the monomers is charged into the reaction system all at once, a method in which a part of the monomers is charged and reacted, and then the remaining monomers are charged all at once, continuously or in portions, and a method in which the monomers are charged continuously or in portions. Examples of the transition metal catalyst include a palladium catalyst and a nickel catalyst. Post-treatment of the polymerization reaction can be carried out using known methods, such as a method of removing water-soluble impurities by liquid separation, a method of adding the reaction solution after the polymerization reaction to a lower alcohol such as methanol, filtering the precipitate, and then drying it, either alone or in combination. When the purity of the first polymer compound is low, it can be purified by a conventional method such as recrystallization, reprecipitation, continuous extraction using a Soxhlet extractor, or column chromatography.

[0235] (Low molecular weight compound (b) having substituent group A) As described above, the polymerization method for producing the polymer compound (B) is not particularly limited. However, because the polymer compound (B) can be easily produced, a polymerization method by a coupling reaction using a transition metal catalyst is preferred, a polymerization method by the Suzuki reaction, the Yamamoto reaction, the Buchwald reaction, or the Stille reaction is more preferred, a polymerization method by the Suzuki reaction or the Yamamoto reaction is even more preferred, and a polymerization method by the Suzuki reaction is particularly preferred. From the above viewpoint, the low molecular weight compound (b) is a compound containing a chlorine atom, a bromine atom, an iodine atom, -OS(=O)2R C1 a group represented by -B(OR C1 )2, a group represented by -BF3Q', a group represented by -MgY', a group represented by -ZnY', and a group represented by -Sn(RC3 )3 (hereinafter, these may be collectively referred to as "substituent group A"), and preferably has at least one selected from the group consisting of a chlorine atom, a bromine atom, an iodine atom, -OS(=O)R C1 a group represented by -B(OR C1 )2, a group represented by -BF3Q', and -Sn(R C1 )3, and more preferably has at least one selected from the group consisting of a chlorine atom, a bromine atom, an iodine atom, -B(OR C1 It is more preferable that the compound has at least one selected from the group consisting of a group represented by -B(OR C1 It is particularly preferred that the alkyl group has at least one group selected from the group consisting of groups represented by -B(OR C1 It is particularly preferred that the alkyl group has a group represented by the formula:

[0236] R C1 R may be appropriately selected depending on the polymerization method used in producing the polymer compound (B). C1 is preferably a hydrogen atom, an alkyl group, a cycloalkyl group, or an aryl group, since this facilitates the production of the low molecular weight compound (b), more preferably a hydrogen atom, an alkyl group, or an aryl group, even more preferably a hydrogen atom or an alkyl group, and particularly preferably an alkyl group, and these groups may have a substituent. R C1 The aryl group in R may be appropriately selected depending on the polymerization method used in producing the polymer compound (B). C1 The aryl group in the formula (I) is preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from a monocyclic aromatic hydrocarbon ring, because this facilitates the production of the low molecular weight compound (b), and the group may have a substituent. R C1 The monovalent heterocyclic group in R may be appropriately selected depending on the polymerization method used in producing the polymer compound (B). C1The aryl group in the formula (I) is preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from a monocyclic heterocycle, because this facilitates the production of the low molecular weight compound (b), and the group may have a substituent. R C1 The substituent that R may have may be appropriately selected depending on the polymerization method used in producing the polymer compound (B). C1 The substituents that may be present on the group (b) are preferably a halogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, or a cycloalkoxy group, and more preferably an alkyl group, because this facilitates the production of the low molecular weight compound (b). These groups may further have a substituent, but preferably do not have a further substituent.

[0237] -B(OR C1 Examples of the group represented by formula 2 include groups represented by the following formulas:

[0238] [ka]

[0239] Q' may be appropriately selected depending on the polymerization method used in producing the polymer compound (B). Q' is preferably Li, Na or K, as this facilitates the production of the low molecular weight compound (b).

[0240] Y' may be appropriately selected depending on the polymerization method used in producing the polymer compound (B).

[0241] The substituent group A preferably serves as a polymerizable group in the polymerization for producing the polymer compound (B). Therefore, when the low-molecular-weight compound (b) has the substituent group A, the total number of the substituent group A contained in the low-molecular-weight compound (b) is preferably the same as the number of hydrogen atoms to be removed in the structural unit (b) having a group obtained by removing one or more hydrogen atoms from the low-molecular-weight compound (b), as explained in the section on the polymer compound (B) above. That is, when the low-molecular-weight compound (b) has the substituent group A, the total number of the substituent group A contained in the low-molecular-weight compound (b) is preferably 1 to 5, more preferably 1 to 3, even more preferably 1 or 2, and particularly preferably 2.

[0242] The examples and preferred ranges, etc. described in the above section on low molecular weight compound (b) are examples and preferred ranges, etc. described for low molecular weight compound (b) that does not have substituent group A. Therefore, when low molecular weight compound (b) has substituent group A, unless otherwise specified, the matters described for low molecular weight compound (b) above can be applied by replacing all of the substituents in group A that low molecular weight compound (b) has with hydrogen atoms. Furthermore, when low molecular weight compound (b) has substituent group A, the examples and preferred ranges, etc. described for low molecular weight compound (b) above can be applied to low molecular weight compounds in which all of the substituents in group A that low molecular weight compound (b) has are replaced with hydrogen atoms, unless otherwise specified. For example, when the low molecular weight compound (b) has the substituent group A, the sp 3 The total number of carbon atoms is the sp 3 Based on the total number of carbon atoms, the number of sp atoms contained in the substituent group A contained in the low molecular weight compound (b) is 3 The total number of carbon atoms (i.e., R C1 sp included in 3 For example, if low molecular weight compound (b) has substituent group A, the molecular weight of low molecular weight compound (b) described in the section on low molecular weight compound (b) is the molecular weight of the low molecular weight compound in which all of the substituent group A of low molecular weight compound (b) have been replaced with hydrogen atoms.

[0243] On the other hand, when the low molecular weight compound (b) has the substituent group A, the ΔE ST is the ΔE of a low molecular weight compound in which all of the substituents A in the low molecular weight compound (b) are replaced with 9,9-dimethylfluoren-2-yl groups. ST Let's say. As described above, a low molecular weight compound (b) having a group A of substituents can be suitably used as a monomer in the production of a polymer compound (B). In this case, the group A of substituents functions as a polymerizable group (leaving group), and therefore the group A of substituents is not present in the polymer compound (B). Furthermore, in the polymer compound (B), atoms in the low molecular weight compound (b) that were bonded to the group A of substituents are often bonded to atoms other than hydrogen atoms. Therefore, if all of the group A of substituents in the low molecular weight compound (b) are replaced with hydrogen atoms, the properties may differ significantly from those of the structural unit (b) in the polymer compound (B). Therefore, in order to solve these problems, the present inventors believed that a more optimal structural unit (b) and low molecular weight compound (b) could be obtained by replacing all of the group A of substituents in the low molecular weight compound (b) having the group A of substituents with 9,9-dimethylfluorene, a common monomer. As described above, the ΔE of a low molecular weight compound in which all of the group A of substituents in the low molecular weight compound (b) were replaced with 9,9-dimethylfluoren-2-yl groups was ST It was decided to use the following.

[0244] A low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1'-M): The matters explained in the above section (Low molecular weight compound (b) having substituent group A) can be similarly applied to low molecular weight compounds having a heterocyclic skeleton represented by the aforementioned formula (b0) or the like. For example, a low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1'-M), which is a low molecular weight compound of this embodiment, will be described as an example. A low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1'-M) is a low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1') which further has a substituent group A. Therefore, the examples and preferred ranges, etc. described in the section on low molecular weight compounds having a heterocyclic skeleton represented by formula (b1-1') can be applied to examples and preferred ranges, etc. of low molecular weight compounds in which all of the substituents in group A of the low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1'-M) have been replaced with hydrogen atoms. The low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1'-M) may be, for example, a low molecular weight compound having a heterocyclic skeleton represented by formula (b1-2'-M).

[0245] [ka] [In the formula, ring R b1 , ring R b2 , ring R b3 , ring R b4 , ring R b5 , X b2 , X b4 , ring R Xb1 and ring R Xb2 has the same meaning as above.]

[0246] Examples of the low molecular weight compound (b) having the substituent group A include the low molecular weight compounds exemplified in the above section on the low molecular weight compound (b) having 1 to 3 substituent groups A, and the compounds BM1 to BM4 described below, including low molecular weight compounds represented by the following formula: 1 and Z 3 has the same meaning as above. Z 4 represents at least one selected from the group consisting of the substituent group A. 4 When there are multiple groups, they may be the same or different.

[0247] [ka]

[0248] [ka]

[0249] [ka]

[0250] [High molecular compound (H)] The polymer compound (H) is preferably a polymer compound containing at least one structural unit selected from the group consisting of structural units represented by formula (X) and structural units represented by formula (Y), since this provides the light-emitting device of this embodiment with better external quantum efficiency.

[0251] The polymer compound (H) preferably contains a structural unit represented by formula (Y), since this leads to better external quantum efficiency of the light-emitting device of this embodiment. Examples and preferred ranges of the constitutional unit represented by formula (Y) in polymer compound (H) are the same as the examples and preferred ranges of the constitutional unit represented by formula (Y) in polymer compound (B). When the polymer compound (H) contains a constitutional unit represented by formula (Y), the content of the constitutional unit represented by formula (Y) contained in the polymer compound (H) is determined so that the function of the polymer compound (H) is not impaired. When the polymer compound (H) contains a structural unit represented by formula (Y), the content of the structural unit represented by formula (Y) contained in the polymer compound (H) is, for example, 1 to 100 mol % relative to the total content of structural units contained in the polymer compound (H), and since the external quantum efficiency of the light-emitting device of this embodiment is more excellent, it is preferably 10 to 100 mol %, more preferably 30 to 100 mol %, even more preferably 50 to 100 mol %, particularly preferably 70 to 100 mol %, and especially preferably 90 to 100 mol %. In the polymer compound (H), the structural unit represented by formula (Y) may be contained in the polymer compound (H) in one type or in two or more types.

[0252] The polymer compound (H) preferably contains a structural unit represented by formula (X), since the polymer compound (H) has excellent hole transport properties and the light-emitting device of this embodiment has excellent external quantum efficiency. Examples and preferred ranges of the constitutional unit represented by formula (X) in polymer compound (H) are the same as the examples and preferred ranges of the constitutional unit represented by formula (X) in polymer compound (B). When the polymer compound (H) contains a structural unit represented by formula (X), the content of the structural unit represented by formula (X) contained in the polymer compound (H) may be within a range that allows the polymer compound (H) to exhibit its functions. When the polymer compound (H) contains a structural unit represented by formula (X), the content of the structural unit represented by formula (X) contained in the polymer compound (H) is, for example, 0.01 to 100 mol % relative to the total content of structural units contained in the polymer compound (H). In order to achieve excellent hole transport properties of the polymer compound (H) and to further improve the external quantum efficiency of the light-emitting device of this embodiment, the content is preferably 0.1 to 90 mol %, more preferably 0.2 to 70 mol %, even more preferably 0.5 to 50 mol %, particularly preferably 1 to 30 mol %, and particularly preferably 2 to 10 mol %. In the polymer compound (H), the structural unit represented by formula (X) may be contained in the polymer compound (H) either alone or in combination of two or more types.

[0253] The polymer compound (H) preferably contains a structural unit represented by formula (Y) and a structural unit represented by formula (X), since the polymer compound (H) has excellent hole transport properties and the external quantum efficiency of the light-emitting device of this embodiment is further improved. When the polymer compound (H) contains a structural unit represented by formula (Y) and a structural unit represented by formula (X), the total content of the structural unit represented by formula (Y) and the structural unit represented by formula (X) contained in the polymer compound (H) may be within a range that allows the polymer compound (H) to function. When the polymer compound (H) contains a structural unit represented by formula (Y) and a structural unit represented by formula (X), the total content of the structural unit represented by formula (Y) and the structural unit represented by formula (X) contained in the polymer compound (H) is, for example, 1 to 100 mol%, and is preferably 10 to 100 mol%, more preferably 30 to 100 mol%, even more preferably 50 to 100 mol%, particularly preferably 70 to 100 mol%, and particularly preferably 90 to 100 mol%, because this provides excellent hole transport properties for the polymer compound (H) and further improves the external quantum efficiency of the light-emitting device of this embodiment.

[0254] Examples of the polymer compound (H) include polymer compounds HP-1 to HP-3.

[0255] [Table 2] [In the table, p, q, and r represent the molar ratio (mol %) of each structural unit. p+q+r=100, and 100≧p+q≧70. Other structural units refer to structural units other than the structural unit represented by formula (Y) and the structural unit represented by formula (X)]

[0256] The polymer compound (H) may be any of a block copolymer, a random copolymer, an alternating copolymer, a graft copolymer, or other forms, but is preferably a copolymer obtained by copolymerizing a plurality of raw material monomers.

[0257] Examples and preferred ranges of the polystyrene-equivalent number average molecular weight of polymer compound (H) are the same as the examples and preferred ranges of the polystyrene-equivalent number average molecular weight of polymer compound (B). Examples and preferred ranges of the polystyrene-equivalent weight average molecular weight of polymer compound (H) are the same as the examples and preferred ranges of the polystyrene-equivalent weight average molecular weight of polymer compound (B).

[0258] (Method for producing polymer compound (H)) The polymer compound (H) can be produced by the same method as the polymer compound (B).

[0259] [Low molecular compound (h)] The molecular weight of the low molecular weight compound (h) is preferably 1×10 because the external quantum efficiency of the light emitting device of this embodiment is superior and the low molecular weight compound (h) is easy to synthesize. 2 ~1×10 4 and more preferably 2×10 2 ~8×10 3 and more preferably 3×10 2 ~6×10 3 and particularly preferably 4 × 10 2 ~4×10 3 and particularly preferably 4×10 2 ~2×10 3 is.

[0260] The low molecular weight compound (h) has sp 3 The low molecular weight compound (h) may contain only one type of polycyclic aromatic hydrocarbon ring skeleton (h) containing carbon atoms, or may contain two or more types. When the low molecular weight compound (h) contains an aromatic hydrocarbon ring skeleton (h), the number of types of aromatic hydrocarbon ring skeletons (h) is usually 1 to 30, and since the external quantum efficiency of the light-emitting device of this embodiment is superior and the synthesis of the low molecular weight compound (h) is easy, the number of types is preferably 1 to 10, more preferably 1 to 7, even more preferably 1 to 5, particularly preferably 1 to 3, especially preferably 1 or 2, and especially more preferably 1. The low molecular weight compound (h) may contain only one aromatic hydrocarbon ring skeleton (h), or may contain two or more aromatic hydrocarbon ring skeletons (h). When the low molecular weight compound (h) contains an aromatic hydrocarbon ring skeleton (h), the number of aromatic hydrocarbon ring skeletons (h) is usually 1 to 50. Since the external quantum efficiency of the light-emitting device of this embodiment is superior and the synthesis of the low molecular weight compound (h) is easy, the number of aromatic hydrocarbon ring skeletons (h) is preferably 1 to 30, more preferably 1 to 20, still more preferably 1 to 10, particularly preferably 1 to 7, particularly preferably 1 to 5, particularly preferably 1 to 3, and particularly preferably 1. The low molecular weight compound (h) has sp 3 One polycyclic heterocyclic skeleton (h) containing carbon atoms The low molecular weight compound (h) may contain only one heterocyclic skeleton (h), or may contain two or more heterocyclic skeletons (h). When the low molecular weight compound (h) contains a heterocyclic skeleton (h), examples and preferred ranges of the type and number of the heterocyclic skeletons (h) are the same as the examples and preferred ranges of the type and number of the aromatic hydrocarbon ring skeletons (h) when the low molecular weight compound (h) contains an aromatic hydrocarbon ring skeleton (h).

[0261] The aromatic hydrocarbon ring skeleton (h) is an aromatic hydrocarbon ring described in the above section on "aromatic hydrocarbon groups" that does not contain sp 3 The polycyclic aromatic hydrocarbon ring containing carbon atoms is preferably a ring having sp 1 in the ring, since the external quantum efficiency of the light-emitting element of this embodiment is superior. 3 It is an aromatic hydrocarbon ring having 2 to 7 rings containing carbon atoms, and more preferably sp 3 It is a 3- to 6-cyclic aromatic hydrocarbon ring containing carbon atoms, more preferably dibenzocycloheptene, dihydrophenanthrene, fluorene, benzofluorene, dibenzofluorene, indenofluorene or spirobifluorene, particularly preferably fluorene, benzofluorene, dibenzofluorene, indenofluorene or spirobifluorene, and particularly preferably fluorene or spirobifluorene. The heterocyclic skeleton (h) is a heterocyclic group having sp atoms in the ring among the heterocyclic rings described in the "heterocyclic group" section above. 3 The polycyclic heterocycle containing carbon atoms is preferably a heterocyclic ring containing sp 1 or sp 2 in the ring, since the external quantum efficiency of the light-emitting element of this embodiment is superior. 3 It is a heterocyclic ring having 2 to 7 carbon atoms, and more preferably sp 3 It is a heterocyclic ring having 3 to 6 carbon atoms, more preferably 9,10-dihydroacridine, indenocarbazole, azaindenocarbazole, diazaindenocarbazole or benzoindenocarbazole, and particularly preferably indenocarbazole or benzoindenocarbazole.

[0262] The low molecular weight compound (h) having an aromatic hydrocarbon ring skeleton (h) and / or a heterocyclic skeleton (h) can also be referred to as a low molecular weight compound (h) having an aromatic hydrocarbon group (h) containing an aromatic hydrocarbon ring skeleton (h) and / or a heterocyclic group (h) containing a heterocyclic skeleton (h). The aromatic hydrocarbon group (h) may be a group obtained by removing one or more hydrogen atoms directly bonded to atoms constituting the ring from the aromatic hydrocarbon ring skeleton (h), and this group may have a substituent. The heterocyclic group (h) may be a group obtained by removing one or more hydrogen atoms directly bonded to atoms constituting the ring from the heterocyclic skeleton (h), and this group may have a substituent. The substituents that the aromatic hydrocarbon group (h) and the heterocyclic group (h) may have are preferably a halogen atom, a cyano group, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an aryl group, a monovalent heterocyclic group, or a substituted amino group, because the external quantum efficiency of the light-emitting element of this embodiment is more excellent; more preferably an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, a monovalent heterocyclic group, or a substituted amino group; even more preferably an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group, or a substituted amino group; and these groups may further have a substituent.

[0263] The aryl group in the substituent that the aromatic hydrocarbon group (h) and the heterocyclic group (h) may have is preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from a monocyclic or bicyclic to hexacyclic aromatic hydrocarbon ring, more preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from a monocyclic, bicyclic or tricyclic aromatic hydrocarbon ring, even more preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from benzene, naphthalene, anthracene, phenanthrene, dihydrophenanthrene or fluorene, particularly preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from benzene or fluorene, and particularly preferably a phenyl group, and these groups may further have a substituent.

[0264] The monovalent heterocyclic group in the substituent that the aromatic hydrocarbon group (h) and the heterocyclic group (h) may have is preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from a monocyclic or bicyclic to hexacyclic heterocycle, more preferably a group in which one hydrogen atom directly bonded to an atom constituting the ring has been removed from a monocyclic, bicyclic or tricyclic heterocycle, and even more preferably pyridine, diazabenzene, triazine, azanaphthalene, diazanaphthalene, carbazole, dibenzofuran, dibenzothiophene, phenoxazine, phenothiazine, 9,10-dihydroacridine or 5,1 It is a group obtained by removing, from 0-dihydrophenazine, one hydrogen atom that is directly bonded to an atom that constitutes the ring (preferably a carbon atom or a nitrogen atom), and is particularly preferably a group obtained by removing, from pyridine, diazabenzene, triazine, carbazole, dibenzofuran, dibenzothiophene, phenoxazine, or phenothiazine, one hydrogen atom that is directly bonded to an atom that constitutes the ring (preferably a carbon atom or a nitrogen atom), and is particularly preferably a group obtained by removing, from pyridine, diazabenzene, triazine, or carbazole, one hydrogen atom that is directly bonded to an atom that constitutes the ring (preferably a carbon atom or a nitrogen atom), and these groups may further have a substituent.

[0265] In the substituted amino group in the substituent that the aromatic hydrocarbon group (h) and the heterocyclic group (h) may have, the substituent that the amino group has is preferably an aryl group or a monovalent heterocyclic group, more preferably an aryl group, and these groups may further have a substituent. Examples and preferred ranges of the aryl group and the monovalent heterocyclic group in the substituent that the amino group has are the same as the examples and preferred ranges of the aryl group and the monovalent heterocyclic group in the substituent that the aromatic hydrocarbon group (h) and the heterocyclic group (h) may have, respectively.

[0266] The substituents that the aromatic hydrocarbon group (h) and the heterocyclic group (h) may further have are preferably a halogen atom, a cyano group, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryloxy group, an aryl group, a monovalent heterocyclic group, or a substituted amino group, because these groups provide a more excellent external quantum efficiency for the light-emitting element of this embodiment and facilitate the synthesis of the low molecular weight compound (h), more preferably an alkyl group, a cycloalkyl group, an aryl group, a monovalent heterocyclic group, or a substituted amino group, and even more preferably an alkyl group, a cycloalkyl group, or an aryl group. These groups may further have a substituent, but preferably do not have a further substituent. Examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in the substituent that the aromatic hydrocarbon group (h) and the heterocyclic group (h) may further have are the same as the examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in the substituent that the aromatic hydrocarbon group (h) and the heterocyclic group (h) may have.

[0267] (Low molecular weight compound represented by formula (h-1)) The low molecular weight compound (h) is preferably a low molecular weight compound represented by formula (h-1), since the external quantum efficiency of the light-emitting device of this embodiment is more excellent.

[0268] n 1his usually an integer of 0 to 10, and is preferably an integer of 1 to 7, more preferably an integer of 1 to 5, even more preferably an integer of 1 to 3, and particularly preferably 1 or 2, since the external quantum efficiency of the light-emitting device of this embodiment is more excellent.

[0269] Ar 1h In the ring, there are sp 3 Polycyclic aromatic hydrocarbon rings containing carbon atoms and sp 3 Examples and preferred ranges of polycyclic heterocycles containing carbon atoms include those having sp 3 Polycyclic aromatic hydrocarbon rings containing carbon atoms and heterocyclic skeletons (h) containing sp atoms in the ring 3 The examples and preferred ranges of the polycyclic heterocycle containing carbon atoms are the same as those of the polycyclic heterocycle containing carbon atoms.

[0270] Ar 1h The substituent that may be contained in the group (I) is preferably a halogen atom, a cyano group, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, or an aryloxy group, since the external quantum efficiency of the light-emitting element of this embodiment is more excellent, more preferably an alkyl group, a cycloalkyl group, an alkoxy group, or a cycloalkoxy group, even more preferably an alkyl group or a cycloalkyl group, and particularly preferably an alkyl group, and these groups may further have a substituent. Ar 1h Examples and preferred ranges of the substituents which may be further substituted by the substituents which may be substituted by the aromatic hydrocarbon group (h) and the heterocyclic group (h) are the same as the examples and preferred ranges of the substituents which may be further substituted by the substituents which may be substituted by the aromatic hydrocarbon group (h) and the heterocyclic group (h).

[0271] R 1h Examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in are the same as the examples and preferred ranges of the aryl group, monovalent heterocyclic group and substituted amino group in the substituent that the aromatic hydrocarbon group (h) and heterocyclic group (h) may have, respectively. R 1hExamples and preferred ranges of the substituents which may be further substituted by the substituents which may be substituted by the aromatic hydrocarbon group (h) and the heterocyclic group (h) are the same as the examples and preferred ranges of the substituents which may be further substituted by the substituents which may be substituted by the aromatic hydrocarbon group (h) and the heterocyclic group (h).

[0272] Examples of the low molecular weight compound (h) include compounds represented by the following formula: 1 , Z 2 and Z 3 represents the same meaning as above.

[0273] [ka]

[0274] [ka]

[0275] [ka]

[0276] [ka]

[0277] [ka]

[0278] [ka]

[0279] <Composition> The composition of the present embodiment is a composition containing at least two compounds selected from the group consisting of a polymer compound (B), a polymer compound (H), a low molecular weight compound (h), a hole-transporting low molecular weight compound, a hole-injecting low molecular weight compound, an electron-transporting low molecular weight compound, an electron-injecting low molecular weight compound, and a light-emitting low molecular weight compound, and of the at least two compounds contained in the composition, at least one compound is the polymer compound (B). The composition of the present embodiment may further contain at least one selected from the group consisting of an antioxidant and a solvent.

[0280] The composition of the present embodiment can be suitably used, for example, as a composition for a light-emitting device. Furthermore, a light-emitting device containing the composition of the present embodiment (hereinafter also referred to as "the light-emitting device of the present embodiment") has superior external quantum efficiency.

[0281] The composition of the present embodiment may be, for example, a composition containing only two or more types of polymer compounds (B) (hereinafter also referred to as "composition 1"), or a composition containing one or more types of polymer compounds (B) and at least one compound selected from the group consisting of polymer compound (H), low molecular weight compound (h), hole-transporting low molecular weight compounds, hole-injecting low molecular weight compounds, electron-transporting low molecular weight compounds, electron-injecting low molecular weight compounds, and light-emitting low molecular weight compounds.

[0282] The composition of this embodiment provides a light-emitting device of this embodiment with a superior external quantum efficiency, and is therefore preferably a composition containing a polymer compound (B) and at least one compound selected from the group consisting of a polymer compound (H), a low molecular weight compound (h), a hole-transporting low molecular weight compound, a hole-injecting low molecular weight compound, an electron-transporting low molecular weight compound, an electron-injecting low molecular weight compound, and a light-emitting low molecular weight compound, and more preferably a composition containing a polymer compound (B) and at least one compound selected from the group consisting of a polymer compound (H) and a low molecular weight compound (h) (hereinafter also referred to as "composition 2").

[0283] The composition of this embodiment may be a composition (hereinafter also referred to as "composition 3") that contains a polymer compound (B) and at least one compound selected from the group consisting of a hole-transporting low molecular weight compound, a hole-injecting low molecular weight compound, an electron-transporting low molecular weight compound, an electron-injecting low molecular weight compound, and a light-emitting low molecular weight compound, but does not contain a polymer compound (H) or a low molecular weight compound (h).

[0284] The composition of the present embodiment may contain only one kind or two or more kinds of each of the polymer compound (B), the polymer compound (H), the low molecular weight compound (h), the hole-transporting low molecular weight compound, the hole-injecting low molecular weight compound, the electron-transporting low molecular weight compound, the electron-injecting low molecular weight compound, and the light-emitting low molecular weight compound.

[0285] The number of types of the polymer compound (B), polymer compound (H), low molecular weight compound (h), hole-transporting low molecular weight compound, hole-injecting low molecular weight compound, electron-transporting low molecular weight compound, electron-injecting low molecular weight compound, and light-emitting low molecular weight compound contained in the composition of this embodiment is usually 1 to 20, preferably 1 to 10, more preferably 1 to 5, even more preferably 1 to 3, particularly preferably 1 or 2, and especially preferably 1.

[0286] The total content of the polymer compound (B), the polymer compound (H), the low molecular weight compound (h), the hole-transporting low molecular weight compound, the hole-injecting low molecular weight compound, the electron-transporting low molecular weight compound, the electron-injecting low molecular weight compound, and the light-emitting low molecular weight compound in the composition of this embodiment may be within a range that allows the composition to function as intended. The total content of the polymer compound (B), the polymer compound (H), the low molecular weight compound (h), the hole-transporting low molecular weight compound, the hole-injecting low molecular weight compound, the electron-transporting low molecular weight compound, the electron-injecting low molecular weight compound, and the light-emitting low molecular weight compound in the composition of this embodiment may be, for example, 0.1 to 100 mass% or even 1 to 100 mass% based on the total solid content contained in the composition of this embodiment. In order to achieve superior external quantum efficiency of the light-emitting device of this embodiment, the total content is preferably 10 to 100 mass%, more preferably 30 to 100 mass%, even more preferably 50 to 100 mass%, particularly preferably 70 to 100 mass%, and particularly preferably 90 to 100 mass%.

[0287] [Composition 1] Composition 1 of the present embodiment is a composition containing only two or more types of polymer compounds (B). The number of types of polymer compounds (B) contained in composition 1 of the present embodiment is usually 2 to 20, preferably 2 to 10, more preferably 2 to 5, and even more preferably 2 or 3.

[0288] [Composition 2] Composition 2 of the present embodiment is a composition containing a polymer compound (B) and at least one compound selected from the group consisting of a polymer compound (H) and a low molecular weight compound (h). The number of types of polymer compound (B), polymer compound (H), and low molecular weight compound (h) contained in composition 2 of this embodiment is usually 1 to 20, preferably 1 to 10, more preferably 1 to 5, even more preferably 1 to 3, particularly preferably 1 or 2, and especially preferably 1. In composition 2 of the present embodiment, polymer compound (B) and polymer compound (H) are different polymer compounds, and polymer compound (H) is a polymer compound that does not contain the structural unit (b).

[0289] In composition 2 of this embodiment, the content of polymer compound (B) may be within a range that allows the composition of this embodiment to exhibit its functions. In composition 2 of this embodiment, the content of polymer compound (B) is, for example, 0.1 to 99.9 parts by mass, where the total content of polymer compound (B), polymer compound (H), and low molecular weight compound (h) is taken as 100 parts by mass. In order to improve the external quantum efficiency of the light-emitting device of this embodiment, the content is preferably 1 to 99 parts by mass, more preferably 5 to 95 parts by mass, even more preferably 10 to 90 parts by mass, particularly preferably 20 to 80 parts by mass, even more preferably 30 to 70 parts by mass, and especially more preferably 40 to 60 parts by mass.

[0290] In the composition 2 of this embodiment, the polymer compound (B) preferably interacts with the polymer compound (H) and / or the low molecular weight compound (h) physically, chemically, or electrically. This interaction makes it possible to improve or adjust the light-emitting properties, charge transport properties, or charge injection properties of the composition of this embodiment, and thus the external quantum efficiency of the light-emitting device of this embodiment is superior.

[0291] To take the light-emitting material in composition 2 of the present embodiment as an example, the polymer compound (B) electrically interacts with the polymer compound (H) and / or the low molecular weight compound (h), and electrical energy is efficiently transferred from the polymer compound (H) and / or the low molecular weight compound (h) to the polymer compound (B), thereby making it possible to make the polymer compound (B) emit light more efficiently, and the external quantum efficiency of the light-emitting element of the present embodiment is superior.

[0292] From the above viewpoint, in composition 2 of this embodiment, the external quantum efficiency of the light-emitting device of this embodiment is superior, so that the polymer compound (H) and the low molecular weight compound (h) preferably have at least one function selected from hole injection property, hole transport property, electron injection property, and electron transport property, and are more preferably host materials.

[0293] From the above viewpoint, in composition 2 of this embodiment, the external quantum efficiency of the light-emitting device of this embodiment is superior, so the polymer compound (B) preferably has luminescence properties, and is more preferably a luminescent material.

[0294] From the above viewpoint, in composition 2 of this embodiment, the lowest excited singlet state (S1) of the polymer compound (H) and the low molecular weight compound (h) preferably has a higher energy level than the lowest excited singlet state (S1) of the polymer compound (B), since this results in a more excellent external quantum efficiency of the light-emitting element of this embodiment.

[0295] From the above viewpoint, in composition 2 of the present embodiment, the lowest excited triplet state (T1) of the polymer compound (H) and the low molecular weight compound (h) preferably has a higher energy level than the lowest excited triplet state (T1) of the polymer compound (B), since this results in a more excellent external quantum efficiency of the light-emitting device of the present embodiment.

[0296] Since the light-emitting device of this embodiment can be produced by a wet method, it is preferable that the polymer compound (H) and the low molecular weight compound (h) are soluble in a solvent capable of dissolving the polymer compound (B).

[0297] Composition 2 of this embodiment may be a composition containing a polymer compound (B), at least one compound selected from the group consisting of a polymer compound (H) and a low molecular weight compound (h), and at least one compound selected from the group consisting of a hole-transporting low molecular weight compound, a hole-injecting low molecular weight compound, an electron-transporting low molecular weight compound, an electron-injecting low molecular weight compound, and a light-emitting low molecular weight compound. Composition 2 of this embodiment may also be a composition that further contains at least one compound selected from the group consisting of an antioxidant and a solvent.

[0298] In composition 2 of this embodiment, the hole transporting low molecular weight compound, hole injection low molecular weight compound, electron transporting low molecular weight compound, electron injecting low molecular weight compound, and light emitting low molecular weight compound include the low molecular weight compounds described below in the sections on hole transport material, hole injection material, electron transport material, electron injection material, and light emitting material, respectively. However, the hole transporting low molecular weight compound, hole injection low molecular weight compound, electron transporting low molecular weight compound, electron injecting low molecular weight compound, and light emitting low molecular weight compound are preferably different from the low molecular weight compound (h), and the hole transporting low molecular weight compound, hole injection low molecular weight compound, electron transporting low molecular weight compound, electron injecting low molecular weight compound, and light emitting low molecular weight compound are preferably different from the low molecular weight compound (h). The emissive low molecular weight compounds, hole-injecting low molecular weight compounds, electron-transporting low molecular weight compounds, electron-injecting low molecular weight compounds and light-emitting low molecular weight compounds have sp 3 Polycyclic aromatic hydrocarbon ring skeleton containing carbon atoms and sp 3 It is more preferable that the compound is a low molecular weight compound that does not have a polycyclic heterocyclic skeleton containing carbon atoms (hereinafter also referred to as a low molecular weight compound (Nh)).

[0299] (solvent) In composition 2 of the present embodiment, the composition containing the polymer compound (B), the polymer compound (H) and / or the low molecular weight compound (h), and a solvent (hereinafter also referred to as "ink") is suitable for producing a light-emitting device using a wet method such as spin coating, casting, microgravure coating, gravure coating, bar coating, roll coating, wire bar coating, dip coating, spray coating, screen printing, flexographic printing, offset printing, inkjet printing, capillary coating, or nozzle coating.

[0300] In composition 2 of the present embodiment, the viscosity of the ink may be adjusted depending on the type of printing method. When applied to a printing method in which the solution passes through a discharge device, such as inkjet printing, the viscosity is preferably 1 mPa·s to 20 mPa·s at 25°C to prevent clogging and deflection during discharge.

[0301] In the composition 2 of this embodiment, the solvent contained in the ink is preferably a solvent that can dissolve or uniformly disperse the solid content in the ink. Examples of the solvent include chlorine-based solvents such as 1,2-dichloroethane, 1,1,2-trichloroethane, chlorobenzene, and o-dichlorobenzene; ether-based solvents such as tetrahydrofuran, dioxane, anisole, and 4-methylanisole; aromatic hydrocarbon-based solvents such as toluene, xylene, mesitylene, ethylbenzene, n-hexylbenzene, and cyclohexylbenzene; cyclohexane, methylcyclohexane, n-pentane, n-hexane, n-heptane, n-octane, n-nonane, n-decane, n-dodecane, and bicyclohexyl. aliphatic hydrocarbon solvents such as acetone, methyl ethyl ketone, cyclohexanone, acetophenone, and the like; ester solvents such as ethyl acetate, butyl acetate, ethyl cellosolve acetate, methyl benzoate, phenyl acetate, and the like; polyhydric alcohol solvents such as ethylene glycol, glycerin, 1,2-hexanediol, and the like; alcohol solvents such as isopropyl alcohol and cyclohexanol, and the like; sulfoxide solvents such as dimethyl sulfoxide, and the like; and amide solvents such as N-methyl-2-pyrrolidone and N,N-dimethylformamide, and the like. The solvents may be used alone or in combination of two or more.

[0302] In composition 2 of this embodiment, the content of the solvent in the ink may be within a range that allows the composition of this embodiment to function properly. The content of the solvent in the ink is typically 1,000 to 1,000,000 parts by mass, where the total content of the polymer compound (B), the polymer compound (H), and the low molecular weight compound (h) is taken as 100 parts by mass.

[0303] (hole transport material) Hole transport materials are classified into low molecular weight compounds and high molecular weight compounds. The hole transport material may have a crosslinking group. The hole transport material may be used alone or in combination of two or more types. Examples of low molecular weight compounds include aromatic amine compounds such as triphenylamine and its derivatives, N,N'-di-1-naphthyl-N,N'-diphenylbenzidine (α-NPD), and N,N'-diphenyl-N,N'-di(m-tolyl)benzidine (TPD).

[0304] Examples of the polymer compounds include polyvinylcarbazole and its derivatives; Examples of the polymer compound include polyarylenes having an aromatic amine structure in the chain and derivatives thereof. The polymer compound may be a compound having an electron-accepting moiety bonded thereto, such as fullerene, tetrafluorotetracyanoquinodimethane, tetracyanoethylene, and trinitrofluorenone.

[0305] When composition 2 of this embodiment contains a hole transport material, the content of the hole transport material may be in a range that allows the composition of this embodiment to function. When composition 2 of this embodiment contains a hole transport material, the content of the hole transport material is usually 1 to 10,000 parts by mass, where the total content of polymer compound (B), polymer compound (H), and low molecular weight compound (h) is 100 parts by mass.

[0306] (electron transport material) Electron transport materials are classified into low molecular weight compounds and high molecular weight compounds. The electron transport material may have a crosslinking group. The electron transport material may be used alone or in combination of two or more types. Examples of low molecular weight compounds include metal complexes having 8-hydroxyquinoline as a ligand, oxadiazole, anthraquinodimethane, benzoquinone, naphthoquinone, anthraquinone, tetracyanoanthraquinodimethane, fluorenone, diphenyldicyanoethylene, and diphenoquinone, as well as derivatives thereof.

[0307] Examples of the polymer compound include polyphenylene, polyfluorene, and derivatives thereof. The polymer compound may be doped with a metal.

[0308] When composition 2 of this embodiment contains an electron transport material, the content of the electron transport material may be within a range that allows the composition of this embodiment to function. When composition 2 of this embodiment contains an electron transport material, the content of the electron transport material is typically 1 to 10,000 parts by mass, relative to 100 parts by mass of the total content of polymer compound (B), polymer compound (H), and low molecular weight compound (h).

[0309] (Hole injection material and electron injection material) The hole injection material and the electron injection material are each classified into a low molecular weight compound and a high molecular weight compound. The hole injection material and the electron injection material may have a crosslinking group. The hole injection material and the electron injection material may each be used alone or in combination of two or more types. Examples of low molecular weight compounds include metal phthalocyanines such as copper phthalocyanine; carbon; metal oxides such as molybdenum and tungsten; and metal fluorides such as lithium fluoride, sodium fluoride, cesium fluoride, and potassium fluoride.

[0310] Examples of the polymer compound include polyaniline, polythiophene, polypyrrole, polyphenylene vinylene, polythienylene vinylene, polyquinoline, polyquinoxaline, and derivatives thereof; and conductive polymers such as polymers containing an aromatic amine structure in the main chain or side chain.

[0311] When composition 2 of this embodiment contains a hole injection material and / or an electron injection material, the contents of the hole injection material and the electron injection material may be within a range that allows the composition of this embodiment to function. When composition 2 of this embodiment contains a hole injection material and / or an electron injection material, the contents of the hole injection material and the electron injection material are typically 1 to 10,000 parts by mass, relative to 100 parts by mass of the total content of polymer compound (B), polymer compound (H), and low molecular weight compound (h).

[0312] Ion doping The hole injection material and the electron injection material may be doped with ions. When the electron injection material and the electron injection material include a conductive polymer, the electrical conductivity of the conductive polymer is preferably 1×10 -5 S / cm~1×10 3 In order to set the electrical conductivity of the conductive polymer in this range, the conductive polymer can be doped with an appropriate amount of ions. The types of ions doped into the hole injection material and the electron injection material include, for example, anions for the hole injection material and cations for the electron injection material. Examples of anions include polystyrene sulfonate ions, alkylbenzene sulfonate ions, and camphor sulfonate ions. Examples of cations include lithium ions, sodium ions, potassium ions, and tetrabutylammonium ions. The doping ions may be used singly or in combination of two or more kinds.

[0313] (luminescent material) Light-emitting materials are classified into low-molecular-weight compounds and high-molecular-weight compounds. The light-emitting material may have a crosslinking group. The light-emitting material may be used alone or in combination of two or more types. Examples of low molecular weight compounds include naphthalene and its derivatives, anthracene and its derivatives, perylene and its derivatives, and phosphorescent compounds having iridium, platinum, or europium as a central metal. Examples of the polymer compound include polymer compounds containing a constitutional unit represented by formula (Y) and / or a constitutional unit represented by formula (X).

[0314] Examples of the phosphorescent compound include the metal complexes shown below.

[0315] [ka]

[0316] [ka]

[0317] [ka]

[0318] [ka]

[0319] [ka]

[0320] When a light-emitting material is contained in composition 2 of this embodiment, the content of the light-emitting material may be within a range that allows the composition of this embodiment to exhibit its functions. When a light-emitting material is contained in composition 2 of this embodiment, the content of the light-emitting material is typically 1 to 10,000 parts by mass, where the total content of polymer compound (B), polymer compound (H), and low molecular weight compound (h) is 100 parts by mass.

[0321] (antioxidant) Composition 2 of the present embodiment may be a composition containing a polymer compound (B), a polymer compound (H) and / or a low molecular weight compound (h), and an antioxidant. The antioxidant may be any compound that is soluble in the same solvent as the polymer compound (B), the polymer compound (H), and the low molecular weight compound (h) and does not inhibit light emission or charge transport, and examples thereof include phenol-based antioxidants and phosphorus-based antioxidants. The antioxidants may be used alone or in combination of two or more.

[0322] When an antioxidant is contained in composition 2 of this embodiment, the content of the antioxidant may be within a range that allows the composition of this embodiment to exhibit its functions. When an antioxidant is contained in composition 2 of this embodiment, the content of the antioxidant is typically 0.00001 to 10 parts by mass, relative to 100 parts by mass of the total content of polymer compound (B), polymer compound (H), and low molecular weight compound (h). The antioxidants may be used alone or in combination of two or more.

[0323] [Composition 3] Composition 3 of this embodiment is a composition containing polymer compound (B) and at least one selected from the group consisting of a hole-transporting low molecular weight compound, a hole-injecting low molecular weight compound, an electron-transporting low molecular weight compound, an electron-injecting low molecular weight compound, and a light-emitting low molecular weight compound, but is free of polymer compound (H) and low molecular weight compound (h). Composition 3 of this embodiment may further contain at least one selected from the group consisting of an antioxidant and a solvent.

[0324] Examples and preferred ranges of the hole-transporting low-molecular-weight compound, hole-injecting low-molecular-weight compound, electron-transporting low-molecular-weight compound, electron-injecting low-molecular-weight compound, luminescent low-molecular-weight compound, antioxidant, and solvent contained in composition 3 of the present embodiment are the same as the examples and preferred ranges of the hole-transporting low-molecular-weight compound, hole-injecting low-molecular-weight compound, electron-transporting low-molecular-weight compound, electron-injecting low-molecular-weight compound, luminescent low-molecular-weight compound, antioxidant, and solvent contained in composition 2 of the present embodiment, respectively.

[0325] When composition 3 of this embodiment contains a hole-transporting low molecular weight compound, a hole-injecting low molecular weight compound, an electron-transporting low molecular weight compound, an electron-injecting low molecular weight compound, and / or a light-emitting low molecular weight compound, the contents of the hole-transporting low molecular weight compound, the hole-injecting low molecular weight compound, the electron-transporting low molecular weight compound, the electron-injecting low molecular weight compound, and the light-emitting low molecular weight compound may be within a range that allows the composition of this embodiment to function. When composition 3 of this embodiment contains a hole-transporting low molecular weight compound, the contents of the hole-transporting low molecular weight compound, the hole-injecting low molecular weight compound, the electron-transporting low molecular weight compound, the electron-injecting low molecular weight compound, and the light-emitting low molecular weight compound are each typically 1 to 10,000 parts by mass, based on 100 parts by mass of polymer compound (B).

[0326] When an antioxidant is contained in composition 3 of this embodiment, the content of the antioxidant may be within a range that allows the composition of this embodiment to exhibit its functions. When an antioxidant is contained in composition 3 of this embodiment, the content of the antioxidant is typically 0.00001 to 10 parts by mass, relative to 100 parts by mass of the content of polymer compound (B).

[0327] When composition 3 of this embodiment contains a solvent (i.e., a composition containing polymer compound (B) and a solvent), examples and preferred ranges are the same as the examples and preferred ranges described in the section on the ink for composition 2 of this embodiment. When composition 3 of this embodiment contains a solvent, the content of the solvent may be within a range that allows the composition of this embodiment to function. When composition 3 of this embodiment contains a solvent, the content of the solvent is typically 1,000 parts by mass to 1,000,000 parts by mass, assuming that the content of polymer compound (B) is 100 parts by mass.

[0328] <Membrane> The film of this embodiment contains the composition of this embodiment described above. The film of this embodiment is suitable as a light-emitting layer in a light-emitting device. The film of this embodiment can be produced, for example, by the wet method described in the section on ink using composition 3 containing an ink or a solvent. The thickness of the film in this embodiment is usually 1 nm to 10 μm.

[0329] <Light-emitting element> The light emitting device of this embodiment contains the above-described composition. The light-emitting device of this embodiment may include, for example, an anode, a cathode, and an organic layer containing the above-described composition provided between the anode and the cathode.

[0330] The light-emitting element of this embodiment may be a light-emitting element formed using composition 3 containing ink or a solvent, or may be a light-emitting element formed by a wet method described in the section on ink using composition 3 containing ink or a solvent. The light-emitting element of this embodiment may be, for example, a light-emitting element including an anode, a cathode, and an organic layer provided between the anode and the cathode, in which the organic layer is formed using composition 3 containing ink or a solvent, or may be an organic layer formed by a wet method described in the section on ink using composition 3 containing ink or a solvent.

[0331] As described above, the light-emitting element of the present embodiment has an organic layer containing the composition of the present embodiment or an organic layer formed using the composition of the present embodiment (hereinafter, these layers are also collectively referred to as "layers of the present embodiment").

[0332] [Layer composition] The layer of this embodiment is usually one or more layers selected from the group consisting of a light-emitting layer, a hole-transporting layer, a hole-injecting layer, an electron-transporting layer, and an electron-injecting layer, and is preferably a light-emitting layer. These layers can be formed using the same method as for producing the above-mentioned film. Layers other than the layer of this embodiment, such as the light-emitting layer, hole-transport layer, hole-injection layer, electron-transport layer, and electron-injection layer, each contain a light-emitting material, a hole-transport material, a hole-injection material, an electron-transport material, and an electron-injection material. These layers can be formed by using, for example, a vapor deposition method or a wet method.

[0333] The light-emitting element has a light-emitting layer between an anode and a cathode. From the viewpoint of hole injection and hole transport properties, the light-emitting element of this embodiment preferably has at least one hole injection layer and hole transport layer between the anode and the light-emitting layer, and from the viewpoint of electron injection and electron transport properties, preferably has at least one electron injection layer and electron transport layer between the cathode and the light-emitting layer.

[0334] Examples of materials for the hole transport layer, electron transport layer, light-emitting layer, hole injection layer, and electron injection layer include the composition of this embodiment as well as the hole transport material, electron transport material, light-emitting material, hole injection material, and electron injection material described above, respectively. When the materials for the hole transport layer, electron transport layer, and light-emitting layer are soluble in a solvent used to form the hole transport layer, electron transport layer, and layer adjacent to the light-emitting layer in the fabrication of a light-emitting device, the materials preferably have a crosslinking group to prevent the materials from dissolving in the solvent. After forming each layer using a material having a crosslinking group, the layer can be made insoluble by crosslinking the crosslinking group.

[0335] [Substrate / Electrode] The substrate in the light-emitting element may be any substrate on which electrodes can be formed and which is not chemically changed when an organic layer is formed, such as a substrate made of a material such as glass, plastic, silicon, etc. In the case of an opaque substrate, it is preferable that the electrode farthest from the substrate is transparent or translucent.

[0336] Examples of materials for the anode include conductive metal oxides and translucent metals, and preferred are indium oxide, zinc oxide, and tin oxide; conductive compounds such as indium tin oxide (ITO) and indium zinc oxide; silver-palladium-copper composite (APC); NESA, gold, platinum, silver, and copper.

[0337] Cathode materials include, for example, metals such as lithium, sodium, potassium, rubidium, cesium, beryllium, magnesium, calcium, strontium, barium, aluminum, zinc, and indium; alloys of two or more of these; alloys of one or more of these with one or more of silver, copper, manganese, titanium, cobalt, nickel, tungsten, and tin; and graphite and graphite intercalation compounds. Examples of alloys include magnesium-silver alloy, magnesium-indium alloy, magnesium-aluminum alloy, indium-silver alloy, lithium-aluminum alloy, lithium-magnesium alloy, lithium-indium alloy, and calcium-aluminum alloy. The anode and cathode may each have a laminated structure of two or more layers.

[0338] [Application] The light-emitting element of this embodiment can be suitably used as a light source for backlighting of a liquid crystal display device, a light source for illumination, an organic EL light source, and a display device for a computer, a television, a mobile terminal, etc. (for example, an organic EL display and an organic EL television). [Example]

[0339] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0340] In the examples, the polystyrene-equivalent number average molecular weight (Mn) and polystyrene-equivalent weight average molecular weight (Mw) of the polymer compound were determined by size exclusion chromatography (SEC) using tetrahydrofuran as the mobile phase. The SEC measurement conditions were as follows: The polymer compound to be measured was dissolved in tetrahydrofuran at a concentration of approximately 0.05% by mass, and 10 μL of the solution was injected into the SEC. The mobile phase was run at a flow rate of 2.0 mL / min. The column used was a PLgel MIXED-B (manufactured by Polymer Laboratories). The detector used was a UV-VIS detector (manufactured by Shimadzu Corporation, product name: SPD-10Avp).

[0341] ΔE of the compound ST The calculation of the ΔE value of the compound was carried out by optimizing the ground state of the compound using the density functional theory at the B3LYP level. At that time, 6-31G* was used as the basis function. Then, using the obtained optimized structure, the ΔE value of the compound was calculated using the time-dependent density functional theory at the B3LYP level. ST The calculation was performed using Gaussian09 as a quantum chemistry calculation program.

[0342] The maximum peak wavelength of the emission spectrum of the polymer compound at room temperature was measured at room temperature using a spectrophotometer (FP-8550, manufactured by JASCO Corporation). The polymer compound was dissolved in xylene at a concentration of approximately 0.8% by mass. The resulting xylene solution was spin-coated onto a quartz substrate, and then heated at 170°C for 10 minutes in a nitrogen atmosphere to form a polymer compound film. The resulting film was used as a measurement sample. As the excitation light, ultraviolet (UV) light with a wavelength of 300 nm was used.

[0343] <Compounds M1 to M11, BM1 to BM4, BCM1, and HM1 to HM5> Compound M1 was synthesized according to the method described in JP 2011-174062 A. Compound M2 was synthesized according to the method described in WO 2005 / 049546. Compound M3 was a commercially available product. Compound M4 was synthesized according to the method described in JP-A-2008-106241. Compound M5 was synthesized according to the method described in JP-A-2010-189630. Compound M6 was synthesized according to the method described in WO 2013 / 191088. Compound M7 was synthesized according to the method described in WO 2015 / 008851. Compound M8 was a commercially available product. Compound M9 was synthesized according to the method described in WO 2016 / 031639. Compound M10 was synthesized according to the method described in WO 2012 / 086671. Compound M11 was a commercially available product. Compound BM1 was synthesized according to the method described in Japanese Patent Application Laid-Open No. 2022-13757. Compounds BM2 to BM4 were synthesized according to the method described in WO 2018 / 212169. Compound BCM1 was synthesized according to the method described in WO 2019 / 004248. Compound HM1 was synthesized according to the method described in WO 2007 / 058368. Compound HM2 was synthesized according to the method described in WO 2010 / 136109. The compound HM3 used was manufactured by 1-Material. Compound HM4 was synthesized according to the method described in WO 2018 / 198971. Compound HM5 was synthesized according to the method described in JP-A-2023-158646.

[0344] [ka]

[0345] [ka]

[0346] [ka]

[0347] [ka]

[0348] [ka]

[0349] [ka]

[0350] <Synthesis Example> Synthesis of polymer compounds HTL, BP1 to BP5, BCP1 and HP1 The polymer compounds HTL, BP1 to BP5, BCP1, and HP1 were synthesized using the compounds of the types and molar ratios shown in Table 3 by the synthesis methods shown in the same table. The Mn and Mw of the obtained polymer compounds were as shown in Table 3. The synthesis of the polymer compound HTL will be explained as an example below. The polymer compound HTL was synthesized using compounds M1, M2, M3, and M4 according to the method described in JP 2012-144722 A. The Mn of the polymer compound HTL was 7.8 × 10 4 and Mw is 2.6 × 10 5 It was. The polymer compound HTL is a copolymer having a molar ratio of 50:30:12.5:7.5 of structural units derived from compound M1, structural units derived from compound M2, structural units derived from compound M3, and structural units derived from compound M4, based on the theoretical value calculated from the amounts of the raw materials charged.

[0351] [Table 3]

[0352] The maximum peak wavelength of the emission spectrum of the polymer compound BCP1 at room temperature was 450 nm, and the half-width of the maximum peak of the emission spectrum of the polymer compound BCP1 at room temperature was 24 nm. The maximum peak wavelength of the emission spectrum of polymer compound BP1 at room temperature was 523 nm, and the half-width of the maximum peak of the emission spectrum of compound BP1 at room temperature was 58 nm. The maximum peak wavelength of the emission spectrum of polymer compound BP2 at room temperature was 507 nm, and the half-width of the maximum peak of the emission spectrum of compound BP2 at room temperature was 31 nm. The maximum peak wavelength of the emission spectrum of polymer compound BP3 at room temperature was 456 nm, and the half-width of the maximum peak of the emission spectrum of compound BP3 at room temperature was 18 nm. The maximum peak wavelength of the emission spectrum of polymer compound BP4 at room temperature was 459 nm, and the half-width of the maximum peak of the emission spectrum of compound BP4 at room temperature was 17 nm. The maximum peak wavelength of the emission spectrum of the polymer compound BP5 at room temperature was 468 nm, and the half-width of the maximum peak of the emission spectrum of the compound BP5 at room temperature was 16 nm.

[0353] ΔE of compounds BM1 to BM4 and BCM1 ST The values ​​of ΔE of compounds BM1' to BM4' and BCM1', in which the two pinacolboryl groups (polymerizable groups) of these compounds were replaced with 9,9-dimethylfluoren-2-yl groups, respectively. ST The value was set as: ΔE of compound BM1 ST As an example, the value of ΔE ST The value of ΔE ST The value was set as:

[0354] [ka]

[0355] ΔE of compound BM1' (compound BM1) ST The value of was 0.33 eV. ΔE of compound BM2' (compound BM2) ST The value of was 0.30 eV. ΔE of compound BM3' (compound BM3) ST The value was 0.37 eV. ΔE of compound BM4' (compound BM4) ST The value of was 0.30 eV. ΔE of compound BCM1' (compound BCM1) ST The value was 0.44 eV.

[0356] Example D1 Fabrication and Evaluation of Light-Emitting Device D1 (Formation of anode and hole injection layer) An anode was formed by sputtering a 45 nm thick ITO film on a glass substrate. A 35 nm thick film of hole injection material ND-3202 (manufactured by Nissan Chemical Industries, Ltd.) was then formed on the anode by spin coating. The substrate with the hole injection layer laminated thereon was heated on a hot plate at 50°C for 3 minutes in an air atmosphere, and then further heated at 230°C for 15 minutes to form a hole injection layer. (Formation of hole transport layer) The polymer compound HTL was dissolved in xylene at a concentration of 0.7% by mass. The resulting xylene solution was used to form a film with a thickness of 20 nm on the hole injection layer by spin coating, and the film was heated on a hot plate at 200°C for 30 minutes in a nitrogen gas atmosphere to form a hole transport layer. This heating caused the polymer compound HTL to become crosslinked. (Formation of the Light-Emitting Layer) Polymer compound BP1 and compound HM5 (polymer compound BP1 / compound HM5=50% by mass / 50% by mass) were dissolved in toluene at a concentration of 2% by mass. The resulting toluene solution was spin-coated onto the hole transport layer to form a film with a thickness of 60 nm. The film was then heated at 130°C for 10 minutes in a nitrogen gas atmosphere to form an emitting layer. (Cathode formation) The substrate on which the first layer was formed was placed in a deposition machine. -4 After reducing the pressure to 0.05 Pa or less, sodium fluoride was deposited on the light-emitting layer to a thickness of about 4 nm, and then aluminum was deposited on the sodium fluoride layer to a thickness of about 80 nm as a cathode. After the deposition, the substrate on which the cathode was formed was sealed with a glass substrate to produce light-emitting device D1. (Evaluation of light-emitting elements) EL light emission was observed by applying a voltage to the light-emitting element D1. 2 The external quantum efficiency and CIE chromaticity coordinates were measured.

[0357] <Examples D2 to D4 and Comparative Example CD1> Fabrication and Evaluation of Light-Emitting Devices D2 to D4 and CD1 Light-emitting devices D2 to D4 were manufactured in the same manner as in Example D1, except that the materials and composition ratios (mass%) listed in Table 4 were used instead of "polymer compound BP1 and compound HM5 (polymer compound BP1 / compound HM5=50% by mass / 50% by mass)" in Example D1 (formation of the light-emitting layer). and CD1 were produced. EL light emission was observed by applying a voltage to the light-emitting elements D2 to D4 and CD1. 2 The external quantum efficiency and CIE chromaticity coordinates were measured.

[0358] The results of Examples D1 to D4 and Comparative Example CD1 are shown in Table 4. The external quantum efficiency of the light-emitting elements D1 to D4 is shown as a relative value when the external quantum efficiency of the light-emitting element CD1 is set to 1.00.

[0359] [Table 4]

[0360] <Examples D5 to D6 and Comparative Example CD2> Fabrication and Evaluation of Light-Emitting Devices D5, D6, and CD2 Light-emitting devices D5, D6, and CD2 were prepared in the same manner as in Example D1, except that the materials and composition ratios (mass%) listed in Table 5 were used instead of "polymer compound BP1 and compound HM5 (polymer compound BP1 / compound HM5=50% by mass / 50% by mass)" in Example D1 (formation of the light-emitting layer). EL light emission was observed by applying a voltage to the light-emitting elements D5, D6, and CD2. 2 The external quantum efficiency and CIE chromaticity coordinates were measured.

[0361] The results of Examples D5 and D6 and Comparative Example CD2 are shown in Table 5. The external quantum efficiency of the light-emitting devices D5 and D6 is shown as a relative value when the external quantum efficiency of the light-emitting device CD2 is set to 1.00.

[0362] [Table 5]

[0363] <Examples D7 to D9 and Comparative Example CD3> Fabrication and Evaluation of Light-Emitting Devices D7 to D9 and CD3 Light-emitting devices D7 to D9 and CD3 were prepared in the same manner as in Example D1, except that the materials and composition ratios (mass%) listed in Table 6 were used instead of "polymer compound BP1 and compound HM5 (polymer compound BP1 / compound HM5=50% by mass / 50% by mass)" in Example D1 (formation of the light-emitting layer). EL light emission was observed by applying a voltage to the light-emitting elements D7 to D9 and CD3. 3000cd / m of optical elements D7 to D9 and CD3 2 The external quantum efficiency and CIE chromaticity coordinates were measured.

[0364] The results of Examples D7 to D9 and Comparative Example CD3 are shown in Table 6. The external quantum efficiency of light-emitting devices D7 to D9 is shown as a relative value when the external quantum efficiency of light-emitting device CD3 is set to 1.00.

[0365] [Table 6]

[0366] <Examples D10 and D11> Fabrication and evaluation of light-emitting devices D10 and D11 Light-emitting devices D10 and D11 were produced in the same manner as in Example D1, except that the materials and composition ratios (mass %) listed in Table 7 were used instead of "polymer compound BP1 and compound HM5 (polymer compound BP1 / compound HM5=50% by mass / 50% by mass)" in Example D1 (formation of the light-emitting layer). EL light emission was observed by applying a voltage to the light-emitting devices D10 and D11. 2 The external quantum efficiency and CIE chromaticity coordinates were measured.

[0367] The results of Examples D10 and D11 are shown in Table 7. The external quantum efficiency of the light-emitting device D10 is shown as a relative value when the external quantum efficiency of the light-emitting device D11 is set to 1.00.

[0368] [Table 7]

[0369] Example D12 and Comparative Example CD4 Fabrication and Evaluation of Light-Emitting Devices D12 and CD4 Light-emitting devices D12 and CD4 were prepared in the same manner as in Example D1, except that the materials and composition ratios (mass%) listed in Table 6 were used instead of "polymer compound BP1 and compound HM5 (polymer compound BP1 / compound HM5=50% by mass / 50% by mass)" in Example D1 (formation of the light-emitting layer). EL light emission was observed by applying a voltage to the light-emitting devices D12 and CD4. 2 The external quantum efficiency and CIE chromaticity coordinates were measured.

[0370] The results of Example D12 and Comparative Example CD4 are shown in Table 8. The external quantum efficiency of the light-emitting device CD4 was The graph shows the relative value of the external quantum efficiency of the light-emitting device D12 when the external quantum efficiency is set to 1.00.

[0371] [Table 8]

Claims

1. a composition containing at least two compounds selected from the group consisting of a polymer compound (B), a polymer compound (H), a low molecular weight compound (h), a hole-transporting low molecular weight compound, a hole-injecting low molecular weight compound, an electron-transporting low molecular weight compound, an electron-injecting low molecular weight compound, and a light-emitting low molecular weight compound; At least one compound among the at least two compounds is the polymer compound (B), The polymer compound (B) contains a boron atom, a nitrogen atom, an oxygen atom, a sulfur atom, a selenium atom, and sp ３ a polymer compound including a structural unit (b) having a group obtained by removing one or more hydrogen atoms from a low molecular weight compound (b) having a heterocyclic skeleton (b) in which six or more rings are fused, the heterocyclic skeleton including, in the fused ring, at least one selected from the group consisting of carbon atoms, the polymer compound (H) is a polymer compound that does not contain the structural unit (b), The low molecular weight compound (h) has an sp ３ A low molecular weight compound having a polycyclic aromatic hydrocarbon ring skeleton containing carbon atoms, or ３ It is a low molecular weight compound having a polycyclic heterocyclic skeleton containing carbon atoms, The hole transporting low molecular weight compound, the hole injecting low molecular weight compound, the electron transporting low molecular weight compound, the electron injecting low molecular weight compound, and the light emitting low molecular weight compound each have an sp ３ A polycyclic aromatic hydrocarbon ring skeleton containing carbon atoms and sp ３ It is a low molecular weight compound that does not contain a polycyclic heterocyclic skeleton containing carbon atoms, The composition, when the composition does not contain the polymer compound (H) and the low molecular weight compound (h), the low molecular weight compound (b) satisfies at least one of the requirements (i) and (ii). (i) The nitrogen atom, the oxygen atom, the sulfur atom, the selenium atom, and the sp ３ The total number of carbon atoms is 4 or more. (ii) The number of nitrogen atoms contained in the fused ring of the heterocyclic skeleton (b) is 2 or more.

2. 2. The composition according to claim 1, wherein the polymer compound (B) is a polymer compound containing a structural unit having a group obtained by removing one or more hydrogen atoms from a low molecular weight compound (b) having a heterocyclic skeleton (b) that satisfies the requirement (i).

3. The composition according to claim 1, wherein the heterocyclic skeleton (b) is a heterocyclic skeleton represented by formula (b1-1): 【Chemistry 1】 [In the formula, Ring R ｂ１ , ring R ｂ２ , ring R ｂ３ , ring R ｂ４ and ring R ｂ５ each independently represents an aromatic hydrocarbon ring or a heterocyclic ring, and these rings may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. X ｂ１ , X ｂ２ , X ｂ３ and X ｂ４ each independently represents an oxygen atom, a sulfur atom, a selenium atom, or —N(R ｘｂ )-, an alkylene group, or a cycloalkylene group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. R ｘｂ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. X ｂ１ and ring R ｂ１ , X ｂ１ and ring R ｂ２ , X ｂ２ and ring R ｂ１ , X ｂ２ and ring R ｂ３ , X ｂ３ and ring R ｂ２ , X ｂ３ and ring R ｂ４ , X ｂ４ and ring R ｂ４ , X ｂ４ and ring R ｂ５ , ring R ｂ２ and ring R ｂ３ , ring R ｂ２ and ring R ｂ５ , and ring R ｂ３ and ring R ｂ５ may each independently bond directly or via a divalent or higher valent group which may have a substituent to form a ring. When a plurality of such substituents are present, they may be the same or different and may bond to each other to form a ring together with the atom to which they are bonded.

4. The low molecular weight compound having a heterocyclic skeleton represented by the formula (b1-1) further satisfies the requirement (ii) and ｂ１ , the X ｂ２ , the X ｂ３ and the X ｂ４ At least two of the following are -N(R ｘｂ 4. The composition according to claim 3, wherein the group is a group represented by the formula:

5. The X ｂ１ , the X ｂ２ , the X ｂ３ and the X ｂ４ each independently represents an oxygen atom, a sulfur atom, or —N(R ｘｂ 4. The composition according to claim 3, wherein the group is a group represented by the formula:

6. The sp contained in the low molecular weight compound having a heterocyclic skeleton represented by the formula (b1-1) ３ The composition of claim 3, wherein the total number of carbon atoms is 9 or more.

7. The composition according to claim 3, wherein the low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1) has at least one selected from the group consisting of an aryl group having three or more substituents, and a monovalent heterocyclic group having three or more substituents.

8. The composition according to claim 1, wherein the structural unit (b) is a structural unit represented by formula (BP-1), a structural unit represented by formula (BP-2), or a structural unit represented by formula (BP-3). 【Chemistry 2】 [In the formula, M ＢＰ１ represents a group obtained by removing one hydrogen atom from the low molecular weight compound (b). M ＢＰ２ represents a group obtained by removing two hydrogen atoms from the low molecular weight compound (b). M ＢＰ３ represents a group obtained by removing three hydrogen atoms from the low molecular weight compound (b). L ＢＰ１ represents an alkylene group, a cycloalkylene group, an arylene group, a divalent heterocyclic group, -N(R ＢＰ１ )-, an oxygen atom, or a sulfur atom, and these groups have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. ＢＰ１ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. ＢＰ１ When there are a plurality of groups, they may be the same or different. n ＢＰ１ represents an integer of 0 or more and 10 or less. Ar ＢＰ１ represents a hydrocarbon group or a heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded.]

9. The composition according to claim 1, wherein the polymer compound (B) further comprises at least one structural unit selected from the group consisting of a structural unit represented by formula (X) and a structural unit represented by formula (Y): 【Transformation 3】 [In the formula, a Ｘ１ and a Ｘ２ each independently represents an integer of 0 or more. Ar Ｘ１ and Ar Ｘ３ each independently represents an arylene group or a divalent heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. Ar Ｘ２ and Ar Ｘ４ each independently represents an arylene group, a divalent heterocyclic group, or a divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. Ｘ２ When a plurality of Ar are present, they may be the same or different. Ｘ４ When there are a plurality of groups, they may be the same or different. R Ｘ１ , R Ｘ２ and R Ｘ３ R each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. Ｘ２ When there are a plurality of R, they may be the same or different. Ｘ３ When there are multiple groups, they may be the same or different. 【Chemistry 4】 [In the formula, Ar Ｙ１ represents an arylene group, a divalent heterocyclic group, or a divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded to each other, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded.]

10. At least one compound among the at least two compounds is the polymer compound (H), 2. The composition according to claim 1, wherein the polymer compound (H) is a polymer compound containing at least one structural unit selected from the group consisting of a structural unit represented by formula (X) and a structural unit represented by formula (Y): 【Transformation 5】 [In the formula, a Ｘ１ and a Ｘ２ each independently represents an integer of 0 or more. Ar Ｘ１ and Ar Ｘ３ each independently represents an arylene group or a divalent heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. Ar Ｘ２ and Ar Ｘ４ each independently represents an arylene group, a divalent heterocyclic group, or a divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. Ｘ２ When a plurality of Ar are present, they may be the same or different. Ｘ４ When there are a plurality of groups, they may be the same or different. R Ｘ１ , R Ｘ２ and R Ｘ３ R each independently represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. Ｘ２ When there are a plurality of R, they may be the same or different. Ｘ３ When there are multiple groups, they may be the same or different. 【Transformation 6】 [In the formula, Ar Ｙ１ represents an arylene group, a divalent heterocyclic group, or a divalent group in which at least one arylene group and at least one divalent heterocyclic group are directly bonded to each other, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded.]

11. At least one compound among the at least two compounds is the low molecular weight compound (h), The composition according to claim 1, wherein the low molecular weight compound (h) is a low molecular weight compound represented by formula (h-1): 【Transformation 7】 [In the formula, n １ｈ represents an integer of 0 or greater. Ar １ｈ is sp in the ring ３ A hydrogen atom n directly bonded to an atom constituting the ring from a polycyclic aromatic hydrocarbon ring containing carbon atoms １ｈ or a group excluding sp ３ From a polycyclic heterocycle containing carbon atoms, a hydrogen atom n directly bonded to an atom constituting the ring １ｈ These groups may have a substituent. When a plurality of the substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. R １ｈ represents an aryl group, a monovalent heterocyclic group, or a substituted amino group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. R １ｈ When a plurality of are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. Ar １ｈ and the substituent that R may have. １ｈ may be bonded to each other to form a ring together with the atoms to which they are bonded.

12. The composition according to any one of claims 1 to 11, further comprising at least one selected from the group consisting of an antioxidant and a solvent.

13. A light-emitting device having an anode, a cathode, and an organic layer provided between the anode and the cathode, A light-emitting device, wherein the organic layer is a layer containing the composition according to any one of claims 1 to 11.

14. A polymeric compound containing a structural unit having a group in which one or more hydrogen atoms have been removed from a low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1'). 【Transformation 8】 [In the formula, Ring R ｂ１ , ring R ｂ２ , ring R ｂ３ , ring R ｂ４ and ring R ｂ５ each independently represents an aromatic hydrocarbon ring or a heterocyclic ring, and these rings may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. X ｂ１ , X ｂ２ , X ｂ３ and X ｂ４ each independently represents an oxygen atom, a sulfur atom, a selenium atom, or —N(R ｘｂ )-, an alkylene group, or a cycloalkylene group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. R ｘｂ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. X ｂ１ and ring R ｂ１ , X ｂ１ and ring R ｂ２ , X ｂ２ and ring R ｂ１ , X ｂ２ and ring R ｂ３ , X ｂ３ and ring R ｂ２ , X ｂ３ and ring R ｂ４ , X ｂ４ and ring R ｂ４ , X ｂ４ and ring R ｂ５ , ring R ｂ２ and ring R ｂ３ , ring R ｂ２ and ring R ｂ５ , and ring R ｂ３ and ring R ｂ５ may each independently bond directly or via a divalent or higher valent group which may have a substituent to form a ring. When a plurality of such substituents are present, they may be the same or different and may bond to each other to form a ring together with the atom to which they are bonded. However, the sp contained in the low molecular weight compound having a heterocyclic skeleton represented by the formula (b1-1′) ３ The total number of carbon atoms is 9 or more, or the low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1′) has at least one selected from the group consisting of an aryl group having three or more substituents and a monovalent heterocyclic group having three or more substituents.]

15. A low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1'-M): 【Chemistry 9】 [In the formula, Ring R ｂ１ , ring R ｂ２ , ring R ｂ３ , ring R ｂ４ and ring R ｂ５ each independently represents an aromatic hydrocarbon ring or a heterocyclic ring, and these rings may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. X ｂ１ , X ｂ２ , X ｂ３ and X ｂ４ each independently represents an oxygen atom, a sulfur atom, a selenium atom, or —N(R ｘｂ )-, an alkylene group, or a cycloalkylene group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. R ｘｂ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. X ｂ１ and ring R ｂ１ , X ｂ１ and ring R ｂ２ , X ｂ２ and ring R ｂ１ , X ｂ２ and ring R ｂ３ , X ｂ３ and ring R ｂ２ , X ｂ３ and ring R ｂ４ , X ｂ４ and ring R ｂ４ , X ｂ４ and ring R ｂ５ , ring R ｂ２ and ring R ｂ３ , ring R ｂ２ and ring R ｂ５ , and ring R ｂ３ and ring R ｂ５ may each independently bond directly or via a divalent or higher valent group which may have a substituent to form a ring. When a plurality of such substituents are present, they may be the same or different and may bond to each other to form a ring together with the atom to which they are bonded. However, the sp contained in the low molecular weight compound having a heterocyclic skeleton represented by the formula (b1-1'-M) ３ In terms of the total number of carbon atoms, the R Ｃ１ sp contained in ３ The number obtained by subtracting the total number of carbon atoms is 9 or more, or the low molecular weight compound represented by formula (b1-1'-M) has at least one selected from the group consisting of an aryl group having three or more substituents and a monovalent heterocyclic group having three or more substituents. In addition, the low molecular weight compound having a heterocyclic skeleton represented by formula (b1-1'-M) does not contain a chlorine atom, a bromine atom, an iodine atom, or an —O—S(═O) ２ R Ｃ１ a group represented by -B(OR Ｃ１ ) ２ a group represented by -BF ３ A group represented by Q′, a group represented by —MgY′, a group represented by —ZnY′, and a group represented by —Sn(R Ｃ１ ) ３ R Ｃ１ represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group, or a monovalent heterocyclic group, and these groups may have a substituent. When a plurality of such substituents are present, they may be the same or different, and may be bonded to each other to form a ring together with the atoms to which they are bonded. R Ｃ１ When a plurality of are present, they may be the same or different and may be bonded to each other to form a ring together with the atoms to which they are bonded. Q' represents Li, Na, K, Rb, or Cs. Y' represents a chlorine atom, a bromine atom, or an iodine atom.]

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