WO2024194264A1

WO2024194264A1 - Materials for organic electroluminescent devices

Info

Publication number: WO2024194264A1
Application number: PCT/EP2024/057174
Authority: WO
Inventors: Philipp Stoessel
Original assignee: Merck Patent Gmbh
Priority date: 2023-03-20
Filing date: 2024-03-18
Publication date: 2024-09-26

Abstract

The present invention relates to silicon compounds and derivatives thereof, and to electronic devices, in particular organic electroluminescent devices, containing said compounds.

Description

Materials for organic electroluminescent devices

The present invention relates to silicon compounds and derivatives of these compounds, as well as electronic devices, in particular organic electroluminescent devices, containing these compounds.

In organic electroluminescent devices (OLEDs), phosphorescent organometallic complexes are often used as emitting materials. In general, there is still room for improvement in OLEDs, especially in OLEDs that exhibit triplet emission (phosphorescence), for example in terms of efficiency, operating voltage and service life. The properties of phosphorescent OLEDs are not only determined by the triplet emitters used. The other materials used, such as matrix materials or charge transport materials, are also of particular importance. Improvements to these materials can therefore also lead to improvements in the OLED properties.

The object of the present invention is to provide compounds which are suitable for use in an OLED, in particular as a matrix material for phosphorescent emitters, as a hole transport material or as an electron blocking material, and which lead to good properties there.

Surprisingly, it has been found that certain compounds, described in more detail below, solve this problem and are well suited for use in OLEDs. The OLEDs in particular have a long service life, high efficiency and low operating voltage. These compounds and electronic devices, in particular organic electroluminescent devices, which contain these compounds are therefore the subject of the present invention.

The present invention therefore relates to a compound containing a partial structure according to the following formula (1),

where the symbols used are:

M is Si, Ge, Sn, Ti, Zr or Hf;

W is the same or different at each occurrence CR or N, where a maximum of one W stands for N per cycle; or the two W together form a group of the following formula (2),

Formula (2) where one of the two dashed bonds represents the bond to N and the other of the two dashed bonds represents the bond to Z;

Z is, at each occurrence, the same or different, a single bond,

BR, CR ₂ , C=O, SiR ₂ , GeR ₂ , NR, P(=O)R, O, S or SO ₂ ;

Y is the same or different at each occurrence and is NR, 0 or S; or Y together with the explicitly drawn carbon atom and the adjacent X forms a group according to the following formula (3) or (4),

Formula (3) Formula (4) where W, Z and X have the meanings given above, the dashed bond marked with * represents the bond to M and the two other dashed bonds represent the linkage of the structure within the formula (1); X is the same or different at each occurrence and is CR or N, with a maximum of two Xs per cycle representing N, or two adjacent Xs in formula (2) together represent CR2, NR, O or S; R is, identically or differently on each occurrence, H, D, F, Cl, Br, I, N(Ar)2, N(R ¹ )2, OAr, SAr, CN, NO2, OR ¹ , SR ¹ , COOR ¹ , C(=O)N(R ¹ )2, Si(R ¹ )3, B(OR ¹ )2, C(=O)R ¹ , P(=O)(R ¹ )2, S(=O)R ¹ , S(=O)2R ¹ , OSO2R ¹ , a straight-chain alkyl group having 1 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where the alkyl, alkenyl or alkynyl group is each linked to one or more radicals R ¹ can be substituted, where one or more non-adjacent CH2 groups can be replaced by Si(R ¹ )2, C=O, NR ¹ , O, S or CONR ¹ , or an aromatic or heteroaromatic ring system with 5 to 40 aromatic ring atoms, which can be substituted by one of the several radicals R ¹ ; two radicals R can also form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system with one another; Ar is on each occurrence, identically or differently, an aromatic or heteroaromatic ring system with 5 to 40 aromatic ring atoms, which can be substituted by one or more radicals R ¹ ; R ¹ is, identically or differently on each occurrence, H, D, F, Cl, Br, I, N(R ² )2, CN, NO2, OR ² , SR ² , Si(R ² )3, B(OR ² )2, C(=O)R ² , P(=O)(R ² )2, S(=O)R ² , S(=O)2R ² , OSO2R ² , a straight-chain alkyl group having 1 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where the alkyl, alkenyl or alkynyl group can each be substituted by one or more radicals R ² , where one or more non-adjacent CH 2 groups can be replaced by Si(R ² ) 2, C=O, NR ² , O, S or CONR ² and where one or more H atoms in the alkyl, alkenyl or alkynyl group can be replaced by D, F, Cl, Br, I or CN, or an aromatic or heteroaromatic ring system with 5 to 40 aromatic ring atoms, which can each be substituted by one or more radicals R ² ; two or more radicals R ¹ can form an aliphatic, aromatic or heteroaromatic ring system with one another; R ² is, on each occurrence, identically or differently, H, D, F, CN or an aliphatic, aromatic or heteroaromatic organic radical, in particular a hydrocarbon radical, having 1 to 20 C atoms, in which one or more H atoms may be replaced by F. In a preferred embodiment of the invention, the compound containing a partial structure of the formula (1) is a compound of the following formula (5) or (6), where the symbols used have the meanings given above and furthermore: R ^M is, identically or differently on each occurrence, F, CN, OR ¹ , OAr, N(R ¹ ) 2, NAr2, Si(R ¹ ) 3, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where the alkyl or alkoxy group may in each case be substituted by one or more radicals R ¹ and where one or more non-adjacent CH 2 groups may be replaced by Si(R ¹ ) 2, C=O, NR ¹ , O, S or CONR ¹ , or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which may be substituted by one of the several radicals R ¹ ; Two R ^M radicals can also form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system with one another, where the two R ^M radicals can be linked by a single bond or by a group selected from C(R ¹ ) 2, O, S, NR ¹ or BR; furthermore, one or more R ^{M radicals} can be linked to one or more R to form a ring system.

An aryl group in the sense of this invention contains 6 to 40 C atoms; a heteroaryl group in the sense of this invention contains 2 to 40 C atoms and at least one heteroatom, with the proviso that the sum of C atoms and heteroatoms is at least 5. The heteroatoms are preferably selected from N, O and/or S. An aryl group or heteroaryl group is understood to be either a simple aromatic cycle, i.e. benzene, or a simple heteroaromatic cycle, for example pyridine, pyrimidine, thiophene, etc., or a condensed (fused) aryl or heteroaryl group, for example naphthalene, anthracene, phenanthrene, quinoline, isoquinoline, etc. Aromatics linked to one another by a single bond, such as biphenyl, are not referred to as aryl or heteroaryl groups, but as aromatic ring systems.

An aromatic ring system in the sense of this invention contains 6 to 60 C atoms, preferably 6 to 40 C atoms in the ring system. A heteroaromatic ring system in the sense of this invention contains 2 to 60 C atoms, preferably 2 to 40 C atoms and at least one heteroatom in the ring system, with the proviso that the sum of C atoms and heteroatoms is at least 5. The heteroatoms are preferably selected of N, O and/or S. An aromatic or heteroaromatic ring system in the sense of this invention is to be understood as a system which does not necessarily only contain aryl or heteroaryl groups, but in which several aryl or heteroaryl groups can also be linked by a non-aromatic unit, such as a C, N or O atom. This also includes systems in which two or more aryl or heteroaryl groups are directly linked to one another, such as biphenyl, terphenyl, bipyridine or phenylpyridine. For example, systems such as fluorene, 9,9'-spirobifluorene, 9,9-diarylfluorene, triarylamine, diaryl ether, stilbene, etc. are to be understood as aromatic ring systems in the sense of this invention, as are systems in which two or more aryl groups are linked, for example, by a short alkyl group. Preferred aromatic or heteroaromatic ring systems are simple aryl or heteroaryl groups as well as groups in which two or more aryl or heteroaryl groups are directly linked to one another, for example biphenyl or bipyridine, as well as fluorene or spirobifluorene.

In the context of the present invention, the term alkyl group includes both linear and branched and/or cyclic alkyl groups, where cyclic alkyl groups can be monocyclic, bicyclic, tricyclic or oligocyclic. The same applies to alkenyl and alkynyl groups.

In the context of the present invention, an aliphatic hydrocarbon radical or an alkyl group or an alkenyl or alkynyl group which can contain 1 to 40 C atoms and in which individual H atoms or CH2 groups can also be substituted by the abovementioned groups, preferably the radicals methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl, neo-pentyl, cyclopentyl, n-hexyl, neo-hexyl, cyclohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, ethenyl, propenyl, butenyl, pentenyl, Cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl or octynyl. An alkoxy group OR ¹ with 1 to 40 C atoms is preferably methoxy, trifluoromethoxy, ethoxy, n-propoxy, i-propoxy, n-Butoxy, i-Butoxy, s-Butoxy, t-Butoxy, n-Pentoxy, s-Pentoxy, 2-Methylbutoxy, n-Hexoxy, Cyclohexyloxy, n-Heptoxy, Cycloheptyloxy, n-Octyloxy, Cyclooctyloxy, 2-Ethylhexyloxy, Pentafluorethoxy and 2,2,2-Trifluorethoxy understood. A thioalkyl group SR ¹ with 1 to 40 carbon atoms includes, in particular, methylthio, ethylthio, n-propylthio, i-propylthio, n-butylthio, i-butylthio, s-butylthio, t-butylthio, n-pentylthio, s-pentylthio, n-hexylthio, cyclohexylthio, n -Heptylthio, cycloheptylthio, n-octylthio, cyclo-octylthio, 2-ethylhexylthio, trifluoromethylthio, pentafluoroethylthio, 2,2,2-trifluoroethylthio, ethenylthio, propenylthio, butenylthio, pentenylthio, cyclopentenylthio, hexenylthio, cyclohexenylthio, heptenylthio, cyclo - heptenylthio, octenylthio, cyclooctenylthio, ethynylthio, propynylthio, Butynylthio, pentynylthio, hexynylthio, heptynylthio or octynylthio. In general, alkyl, alkenyl, alkynyl, alkoxy or thioalkyl groups according to the present invention can be straight-chain, branched or cyclic, where one or more non-adjacent CH2 groups can be replaced by the abovementioned groups; furthermore, one or more H atoms can also be replaced by D, F, CI, Br, I, CN or NO2, preferably by D, F or CN.

An aromatic or heteroaromatic ring system with 5 - 60 aromatic ring atoms, which can also be substituted with the above-mentioned radicals R ¹ , is understood to mean in particular groups which are derived from benzene, naphthalene, anthracene, benzanthracene, phenanthrene, pyrene, chrysene, perylene, fluoranthene, naphthacene, pentacene, benzopyrene, biphenyl, biphenylene, terphenyl, triphenylene, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, cis- or trans-indenofluorene, cis- or trans-indenocarbazole, cis- or trans-indolocarbazole, truxene, isotruxene, spirotruxene, spiroisotruxene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, Dibenzothiophene, pyrrole, indole, isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthimidazole, phenanthrimidazole, Pyridimidazole, pyrazinimidazole, quinoxalinimidazole, oxazole, benzo-oxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, 1,2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, hexaazatriphenylene, benzo- pyridazine, pyrimidine, benzopyrimidine, quinazoline, quinoxaline, 1,5-diaza-anthracene, 2,7-diazapyrene, 2,3-diazapyrene, 1,6-diazapyrene, 1,8-diazapyrene, 4,5-diazapyrene, 4,5,9, 10-tetraazaperylene, pyrazine, Phenazine, phenoxazine, phenothiazine, fluorubin, naphthyridine, azacarbazole, benzocarboline, phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1 ,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, tetrazole, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine, purine, pteridine, indolizine and benzothiadiazole or groups derived from combinations of these systems.

The phrase that two or more radicals can form a ring with one another is to be understood in the context of the present description to mean, among other things, that the two radicals are linked to one another by a chemical bond with formal elimination of two hydrogen atoms. This is illustrated by the following scheme:

Ring formation of the residues R

H,C. ,CH, CH ₂

Analogously, the formation of a fused aromatic ring is possible when two substituents R, each representing alkenyl groups, are linked to each other by a chemical bond with formal elimination of two hydrogen atoms.

Furthermore, the above formulation should also be understood to mean that if one of the two residues represents hydrogen, the second residue binds to the position to which the hydrogen atom was bound, forming a ring. This is illustrated by the following scheme:

Ring formation of the residues R The compounds according to the invention can also be partially or completely deuterated.

In a preferred embodiment of the invention, Y is the same or different on each occurrence and is NR, or Y, together with the explicitly drawn carbon atom and the adjacent X, forms a group according to the formula (3) given above. Very particularly preferably, Y, together with the explicitly drawn carbon atom and the adjacent X, forms a group according to the formula (3) given above.

In a preferred embodiment of the invention, a maximum of one X per cycle is N. Particularly preferred are compounds in which in the two condensed six-membered rings all X are CR, where X is C when this together with the adjacent carbon atom and Y is a group of the formula (3) or (4). Particularly preferably, in the partial structure of the formula (1) or in the compounds of the formulas (5) and (6), all X are CR, where X is C when this together with the adjacent carbon atom and Y is a group of the formula (3) or (4).

Preferred embodiments of the partial structure of formula (1) are thus the structures according to the following formulas (7) and (8),

Formula (7) Formula (8) where the symbols used have the meanings given above and Y in formula (8) stands for NR, O or S, where Y = NR is preferred. Preferred embodiments of the compounds of formulas (5) and (6) are correspondingly the compounds of the following formulas (9), (10), (11) and (12),

Formula (10)

Formula (11) Formula (12) wherein the symbols used have the meanings given above and Y in formula (10) and (12) stands for NR, O or S, with Y = 0 or NR being preferred.

In a further preferred embodiment of the invention, Z is the same or different on each occurrence and represents a single bond, CR2, BR or O, particularly preferably a single bond.

In a further preferred embodiment of the invention, both groups W together represent a group of the following formula (2a), Formula (2a)

Furthermore, an embodiment is preferred in which Z stands for a single bond and in the same cycle one of the two groups W stands for CR and the other group W stands for N.

Particularly preferred partial structures of the formula (1) or the partial structures (7) and (8) are the structures of the following formulas (7a), (7b), (8a) and (8b),

Formula (8a) Formula (8b) where the symbols used have the meanings given above and Y in formulas (8a) and (8b) preferably represents NR, 0 or S where Y = O or NR is particularly preferred. Z in the formulas (7a) and (8a) preferably represents a single bond.

Accordingly, particularly preferred compounds are the compounds of the following formulas (9a), (9b), (10a), (10b), (11 a), (11 b), (12a) and (12b),

R R

Formula (9a) Formula (9b)

R

Formula (10a) Formula (10b)

Formula (11a)

Formula (12b) where the symbols used have the meanings given above and Y in the formulas (10a), (10b), (12a) and (12b) preferably represents NR, O or S, with Y = O or NR being particularly preferred. Z in the formulas (9a), (10a), (11a) and (12a) preferably represents a single bond. Very particular preference is given to the compounds of the following formulae (9a-1 ), (10a-1 ), (1 1 a-1 ) and (12a-1 ),

Formula (9a-1 ) Formula (10a-1 )

Formula (11 a-1 ) Formula (12a-1) where the symbols used have the meanings given above and Y in the formulas (10a-1 ) and (12a-1 ) preferably stands for NR, O or S, with Y = O or NR being particularly preferred. Z preferably stands for a single bond.

In a further preferred embodiment of the invention, M in the partial structure of formula (1), in the compounds of formulas (5) and (6), as well as in the preferred embodiments listed above and below for Si or Ge, particularly preferably for Si.

Preferably, the partial structure of formula (1) or the preferred embodiments of this formula listed above and below has no more than four, preferably no more than two, substituents R bonded to C atoms which are different from H or D.

The compounds of the formulas (5) or (6) or the preferred embodiments of these formulas listed above and below preferably have no more than four substituents R bonded to C atoms which are different from H or D. The compounds particularly preferably have no more than two substituents R bonded to C atoms which are different from H or D.

Preferred substituents R ^M R, R ¹ and R ² on the compounds according to the invention are described below. In a particularly preferred embodiment of the invention, the preferences for R ^M , R, R ¹ and R ² mentioned below occur simultaneously and apply to the structures of the formula (1), the compounds of the formulas (5) and (6), and to all the preferred embodiments listed above.

In a preferred embodiment of the invention, R ^M is on each occurrence, identically or differently, N(R ¹ ) 2, NAr 2, a straight-chain alkyl group having 1 to 6 C atoms or a branched or cyclic alkyl group having 3 to 6 C atoms, in each of which one or more H atoms can be replaced by D, or an aromatic or heteroaromatic ring system having 6 to 13 aromatic ring atoms, which can be substituted by one or more radicals R ¹ ; the two radicals R ^M can also form a ring system with one another. Particularly preferred groups R ^M are selected from the group consisting of methyl, isopropyl, tert-butyl, neopentyl, cyclopentyl, cyclohexyl, phenyl, which can also be substituted by one or more substituents R ¹ , or ortho-, meta- or para-biphenyl, which can also be substituted by one or more substituents R ¹ , where the above-mentioned groups can also be partially or completely deuterated. and where two of these groups can also form a ring with each other and with the M to which they are bonded. If groups R ^M form a ring with each other, this ring is preferably a metallacyclopentyl, metallacyclohexyl or metallafluorene, where "metalla" stands for Si, Ge, Sn, Ti, Zr or Hf. In a further preferred embodiment of the invention, both groups R ^M together represent a group of the following formula (13), where the dashed bonds represent the bonds to M and R ¹ has the meanings given above, where the two R ¹ which are bonded to N are preferably the same or different on each occurrence and represent an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, which can each be substituted by one or more radicals R. Such a group is formed when the two groups R ^M each represent N(R ¹ )2, where an R ¹ radical on one N represents an optionally substituted phenyl group and an R ¹ radical on the other N represents H and these radicals together form a ring system. If Y represents NR, the R radical which is bonded to the nitrogen atom preferably represents an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms which may be substituted by one or more R ¹ radicals, particularly preferably an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms which may be substituted by one or more R ¹ radicals, and very particularly preferably an aromatic or heteroaromatic ring system having 6 to 13 aromatic ring atoms which may be substituted by one or more R ¹ radicals, where Phenyl, ortho-, meta- or para-biphenyl, dibenzofuranyl or carbazolyl, each of which may be substituted by one or more radicals R ¹ , are particularly preferred. Preferred aromatic and heteroaromatic radicals R which are bonded to the nitrogen atom for Y = NR correspond to the preferred aromatic and heteroaromatic radicals R listed below.

In a preferred embodiment of the invention, R is selected on each occurrence, identically or differently, from the group consisting of H, D, F, N(Ar)2, OAr, SAr, CN, ^OR1 , a straight-chain alkyl group having 1 to 10 C atoms or an alkenyl group having 2 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms, where the alkyl or alkenyl group can each be substituted by one or more radicals ^R1 , but is preferably unsubstituted, and where one or more non-adjacent CH2 groups can be replaced by O, or an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, which can be substituted by one or more radicals ^R1 ; two radicals R can also form an aliphatic, aromatic or heteroaromatic ring system with one another. Particularly preferably, R is selected on each occurrence, identically or differently, from the group consisting of H, N(Ar)2, a straight-chain alkyl group having 1 to 6 C atoms, in particular having 1, 2, 3 or 4 C atoms, a straight-chain alkenyl group having 2 to 4 C atoms, in particular having 2 C atoms, or a branched or cyclic alkyl group having 3 to 6 C atoms, where the alkyl or alkenyl group may in each case be substituted by one or more radicals R ¹ , but is preferably unsubstituted, or an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, which may be substituted by one or more radicals R ¹ . Very particularly preferably, R is selected on each occurrence, identically or differently, from the group consisting of H, D or an aromatic or heteroaromatic ring system having 6 to 13 aromatic ring atoms, which may be substituted by one or more radicals R ¹ . In a further preferred embodiment of the invention, Ar is the same or different and represents an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, particularly preferably having 6 to 24 aromatic ring atoms and very particularly preferably having 6 to 13 aromatic ring atoms, which may in each case be substituted by one or more radicals R ¹ .

If R ^M or R is an aromatic or heteroaromatic ring system, this is preferably substituted with non-aromatic radicals R ¹ , whereby for R = triazine, pyrimidine, quinazoline, quinoxaline or carbazole, aromatic or heteroaromatic radicals R ¹ on this heteroaryl group can also be preferred. This preference also applies analogously to the substituents on Ar.

Suitable aromatic or heteroaromatic ring systems R ^M , R or Ar are selected from phenyl, biphenyl, in particular ortho-, meta- or para-biphenyl, terphenyl, in particular ortho-, meta-, para- or branched terphenyl, quaterphenyl, in particular ortho-, meta-, para- or branched quaterphenyl, fluorene, which can be linked via the 1-, 2-, 3- or 4-position, spirobifluorene, which can be linked via the 1-, 2-, 3- or 4-position, naphthalene, which can be linked via the 1- or 2-position, indole, benzofuran, benzothiophene, carbazole, which can be linked via the 1-, 2-, 3- or 4-position, dibenzofuran, which can be linked via the 1-, 2-, 3- or 4-position, dibenzothiophene, which can be linked via the 1-, 2-, 3- or 4-position, indenocarbazole, indolocarbazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, quinazoline, quinoxaline, benzimidazole, phenanthrene, triphenylene or a combination of two or three of these groups, each of which may be substituted by one or more radicals R ¹ .

The aromatic or heteroaromatic groups R ^M or R are preferably selected from the groups of the following formulas R-1 to R- 83,

R-34

R-45 R-46 R-50

R-51 ^R -52 R-53 ^R'54

R-57 R-58

R-67 R-68

where R ¹ has the meanings given above, the dashed bond represents the bond of the group and furthermore:

Ar ¹ is, identically or differently at each occurrence, a bivalent aromatic or heteroaromatic ring system having 6 to 18 aromatic ring atoms, which may each be substituted by one or more radicals R ¹ ; A ¹ is, identically or differently on each occurrence, C(R ¹ ) 2, NR ¹ , 0 or S; or in the formulas R-40, R-41 and R-42, identically or differently on each occurrence, is a single bond, C(R ¹ ) 2, NR ¹ , 0 or S; n is 0 or 1, where n = 0 means that no group A ¹ is bonded at this position and radicals R ¹ are bonded to the corresponding carbon atoms instead; m is 0 or 1; with the proviso that m = 1 for the structures (R-12), (R-17), (R-21), (R-25), (R-26), (R-30), (R-34), (R-38) and (R-39) when these groups are bonded to a nitrogen atom.

If the abovementioned groups R-1 to R-83 have several groups A ¹ , all combinations from the definition of A ¹ are possible. Preferred embodiments are then those in which one group A ¹ is NR ¹ and the other group A ¹ is C(R ¹ ) 2 or in which both groups A ¹ are NR ¹ or in which both groups A ¹ are 0. In a particularly preferred embodiment of the invention, in groups R which have several groups A ¹ , at least one group A ¹ is C(R ¹ ) 2 or NR ¹ .

If A ¹ is NR ¹ , the substituent R ¹ which is bonded to the nitrogen atom preferably represents an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, which may also be substituted by one or more radicals R ^2. In a particularly preferred embodiment, this substituent R ¹ , identical or different on each occurrence, represents an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, preferably having 6 to 12 aromatic ring atoms, which has no condensed aryl groups or heteroaryl groups in which two or more aromatic or heteroaromatic 6-ring groups are directly condensed to one another, and which may also be substituted in each case by one or more radicals R ² . Particularly preferred are phenyl, biphenyl, terphenyl and quaterphenyl with linkage patterns as listed above for R-1 to R-11, where these structures can be substituted by one or more radicals R ² , but are preferably unsubstituted. If A ¹ is C(R ¹ ) 2 , the substituents R ¹ which are bonded to this carbon atom are preferably identical or different on each occurrence and represent a linear alkyl group having 1 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms or an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, which may also be substituted by one or more radicals R ² . R ¹ is very particularly preferably a methyl group or a phenyl group. The radicals R ¹ can also form a ring system with one another, resulting in a spiro system.

In one embodiment of the invention, at least one radical R is an electron-rich heteroaromatic ring system. The electron-rich heteroaromatic ring system is preferably selected from the groups R-13 to R-42 shown above, where in the groups R-13 to R-16, R-18 to R-20, R-22 to R-24, R-27 to R-29, R-31 to R-33 and R-35 to R-37 at least one group A ¹ is NR ¹ , where R ¹ is preferably an aromatic or heteroaromatic ring system, in particular an aromatic ring system. The group R-15 with m = 0 and A ¹ = NR ¹ is particularly preferred.

In a further embodiment of the invention, at least one radical R is an electron-poor heteroaromatic ring system. The electron-poor heteroaromatic ring system is preferably selected from the groups R-47 to R-50, R-57, R-58 and R-76 to R-83 shown above.

In a further preferred embodiment of the invention, R ¹ is the same or different on each occurrence and is selected from the group consisting of H, D, F, CN, OR ² , a straight-chain alkyl group having 1 to 10 C atoms or an alkenyl group having 2 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms, where the alkyl or alkenyl group can each be substituted by one or more radicals R ² and where one or more non-adjacent CH2 groups can be replaced by O, or an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, which can be substituted in each case by one or more radicals R ² ; two or more radicals R ¹ can form an aliphatic ring system with one another. In a particularly preferred embodiment of the invention, R ¹ is the same or different on each occurrence and is selected from the group consisting of H, a straight-chain alkyl group having 1 to 6 C atoms, in particular having 1, 2, 3 or 4 C atoms, or a branched or cyclic alkyl group having 3 to 6 C atoms, where the alkyl group can be substituted by one or more radicals R ² , but is preferably unsubstituted, or an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, which can be substituted in each case by one or more radicals R ² , but is preferably unsubstituted.

In a further preferred embodiment of the invention, R ² is the same or different on each occurrence and is H, F, an alkyl group having 1 to 4 C atoms or an aryl group having 6 to 10 C atoms, which may be substituted by an alkyl group having 1 to 4 C atoms, but is preferably unsubstituted.

Other suitable R groups are groups of the formula -Ar ⁴ -N(Ar ² )(Ar ³ ), where Ar ² , Ar ³ and Ar ⁴ are the same or different on each occurrence and represent an aromatic or heteroaromatic ring system with 5 to 24 aromatic ring atoms, each of which may be substituted by one or more R ¹ radicals. The total number of aromatic ring atoms of Ar ² , Ar ³ and Ar ⁴ is a maximum of 40.

Ar ⁴ and Ar ² can be connected to one another and/or Ar ² and Ar ³ can also be connected to one another by a group selected from C(R ¹ ) 2, NR ¹ , O or S. Preferably, Ar ⁴ and Ar ² are connected to one another or Ar ² and Ar ³ are connected to one another in a position ortho to the position of the connection to the nitrogen atom. In a further embodiment of the invention, none of the groups Ar ² , Ar ³ or Ar ⁴ are connected to one another.

Preferably, Ar ⁴ is an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, in particular having 6 to 12 aromatic tic ring atoms, each of which may be substituted by one or more radicals R ¹ . Ar ⁴ is particularly preferably selected from the group consisting of ortho-, meta- or para-phenylene or ortho-, meta- or para-biphenyl, each of which may be substituted by one or more radicals R ¹ , but is preferably unsubstituted. Ar ⁴ is very particularly preferably an unsubstituted phenylene group. This applies in particular when Ar ⁴ is connected to Ar ² by a single bond.

Preferably, Ar ² and Ar ³ are the same or different on each occurrence and are an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, which may each be substituted by one or more radicals R ¹ . Particularly preferred groups Ar ² and Ar ³ are the same or different on each occurrence and are selected from the group consisting of benzene, ortho-, meta- or para-biphenyl, ortho-, meta-, para- or branched terphenyl, ortho-, meta-, para- or branched quaterphenyl, 1-, 2-, 3- or 4-fluorenyl, 1-, 2-, 3- or 4-spiro-bifluorenyl, 1- or 2-naphthyl, indole, benzofuran, benzothiophene, 1-, 2-

3- or 4-carbazole, 1-, 2-, 3- or 4-dibenzofuran, 1-, 2-, 3- or 4-dibenzothiophene, indenocarbazole, indolocarbazole, 2-, 3- or 4-pyridine, 2-,

4- or 5-pyrimidine, pyrazine, pyridazine, triazine, phenanthrene, triphenylene or combinations of two, three or four of these groups, which may each be substituted by one or more radicals R ^1. Particularly preferably, Ar ² and Ar ³ , identical or different on each occurrence, represent an aromatic ring system having 6 to 24 aromatic ring atoms, which may be substituted by one or more radicals R ¹ , in particular selected from the groups consisting of benzene, biphenyl, in particular ortho-, meta- or para-biphenyl, terphenyl, in particular ortho-, meta-, para- or branched terphenyl, quaterphenyl, in particular ortho-, meta-, para- or branched quaterphenyl, fluorene, in particular 1-, 2-, 3- or 4-fluorene, or spirobifluorene, in particular 1-, 2-, 3- or 4-spirobifluorene.

The alkyl groups in compounds according to the invention which are processed by vacuum evaporation preferably have no more than five C atoms, particularly preferably no more than 4 C atoms, very particularly preferably no more than 1 C atom. For compounds which consist of Also suitable for use in the preparation of a solution are compounds which are substituted with alkyl groups, in particular branched alkyl groups, with up to 10 C atoms or which are substituted with oligoarylene groups, for example ortho-, meta-, para- or branched terphenyl or quaterphenyl groups.

If the compounds containing a partial structure of formula (1) or compounds of formula (5) or (6) or the preferred embodiments are used as matrix material for a phosphorescent emitter or as matrix material in hyperphosphorescent OLEDs or in a layer that is directly adjacent to a phosphorescent layer, it is further preferred if the compound does not contain any condensed aryl or heteroaryl groups in which more than two six-membered rings are directly condensed to one another. In particular, it is preferred that the groups R ^M , R, Ar, R ¹ and R ² do not contain any condensed aryl or heteroaryl groups in which two or more six-membered rings are directly condensed to one another. An exception to this are phenanthrene, triphenylene, quinazoline and quinoxaline, which may be preferred due to their high triplet energy despite the presence of condensed aromatic six-membered rings.

The above-mentioned preferred embodiments can be combined with one another as desired within the limitations defined in claim 1. In a particularly preferred embodiment of the invention, the above-mentioned advantages occur simultaneously.

Examples of suitable compounds according to the embodiments listed above are the compounds listed in the following table.

- k£-

The 8-metalla-diindolo[1,2,3-cd:3′,2′,1′-kl]perimidines (2) according to the invention can be prepared by reacting the 13,14-dihydrocarbazolo-[1,2-a]carbazole (1) with metal electrophiles of the type (R ^M )2MCl2 (M = Si, Ge, Sn, Ti, Zr, Hf; R ^M = alkyl, aryl, heteroaryl) in the presence of a base in a dipolar aprotic solvent (Scheme 1). Particularly suitable combinations of base and solvent are alkyl lithium compounds, such as n-BuLi in ethers, such as diethyl ether, di-n-butyl ether or tetrahydrofuran (THF), or sodium hydride or potassium hydride in THF, dimethylacetamide (DMAc) or dimethyl sulfoxide (DMSO). Scheme 1: If metal electrophiles of the formula MCl4 are used in a stoichiometric ratio of 1:2 to (1), the corresponding 8-metalla-spiro-diindolo[1,2,3-cd:3′,2′,1′-kl]perimidines (3) are obtained (Scheme 2). If two different 13,14-dihydrocarbazolo-[1,2-a]carbazoles (1) are used, the unsymmetrical 8-metalla-spiro-diindolo-[1,2,3-cd:3′,2′,1′-kl]perimidines (3) are also obtained, whereby the synthesis can be carried out statistically or sequentially. Scheme 2: The 6-metalla-diimidazolo[1,2,3-cd:3′,2′,1′-kl]-perimidines (5) according to the invention can be prepared by reacting the 1,10-dihydrodicyclopenta-[a,h]naphthalenes (4) with metal electrophiles of the type (R ^M )2MCl2 (R ^M : alkyl, aryl, heteroaryl) in the presence of a base in a dipolar aprotic solvent (Scheme 3), whereby base-solvent combinations as above for the 8-metalla-diindolo[1,2,3- cd:3′,2′,1′-kl]perimidines (2) can be used.6-Metalla-spirodiimidazolo[1,2,3-cd:3′,2′,1′-kl]perimidines can be prepared analogously to the process described in Scheme 2. The 1,10-dihydrodicyclopenta[a,h]-naphthalenes (4) can be prepared analogously to K. Miyata et al., Angew. Chem. Int. Ed.2011, 50, 4649 from the 2,9-dibromo-1,10-dinitronaphthalenes (3). Scheme 3: The compounds (8) according to the invention containing an imidazole and an indole unit bound to M are accessible from the 1-nitro-2-halogen-11H-benzo[a]-carbazoles (6) analogously to the process described above (Scheme 4). Scheme 4:

For processing the compounds according to the invention from the liquid phase, for example by spin coating or by printing processes, formulations of the compounds according to the invention are required. These formulations can be, for example, solutions, dispersions or emulsions. It may be preferable to use mixtures of two or more solvents for this purpose. Suitable and preferred solvents are, for example, toluene, anisole, o-, m- or p-xylene, methyl benzoate, mesitylene, tetralin, veratrole, THF, methyl-THF, THP, chlorobenzene, dioxane, phenoxytoluene, in particular 3-phenoxytoluene, (-)-fenchone, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, 1-methylnaphthalene, 2-methylbenzothiazole, 2-phenoxyethanol, 2-pyrrolidinone, 3-methylanisole, 4-methylanisole, 3,4-dimethylanisole, 3,5-dimethylanisole, acetophenone, ^-terpineol, benzothiazole, butylbenzoate, cumene, cyclohexanol, cyclohexanone, Cyclohexylbenzene, decalin, dodecylbenzene, ethyl benzoate, indane, NMP, p-cymene, phenetol, 1,4-diisopropylbenzene, dibenzyl ether, diethylene glycol butyl methyl ether, triethylene glycol butyl methyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, tripropylene glycol imethyl ether, tetra-ethylene glycol dimethyl ether, 2-isopropylnaphthalene, pentylbenzene, hexyl-benzene, heptylbenzene, octylbenzene, 1,1-bis(3,4-dimethylphenyl)ethane, 2-methylbiphenyl, 3-methylbiphenyl, 1-methylnaphthalene, 1-ethylnaphthalene, ethyl octanoate, Octyloctanoate, heptylbenzene, Menthyl isovalerate, cyclohexylhexanoate or mixtures of these solvents.

A further subject matter of the present invention is therefore a formulation comprising at least one compound according to the invention and at least one further compound. The further compound can be, for example, a further matrix material and/or a phosphorescent emitter and/or a fluorescent emitter and/or an emitter which exhibits TADF (thermally activated delayed fluorescence) and/or a solvent.

A further subject matter is the use of the compounds according to the invention in an electronic device, in particular in an organic electroluminescent device.

An electronic device in the sense of the present invention is a device which contains at least one layer which contains at least one organic compound. The component can also contain inorganic materials or layers which are made entirely of inorganic materials.

Yet another subject of the invention is an electronic device, in particular an organic electroluminescent device, comprising one or more compounds according to the invention.

The electronic device is preferably selected from the group consisting of organic electroluminescent devices (OLEDs), organic integrated circuits (O-ICs), organic field-effect transistors (O-FETs), organic thin-film transistors (O-TFTs), organic light-emitting transistors (O-LETs), organic solar cells (O-SCs), dye-sensitized organic solar cells (DSSCs), organic optical detectors, organic photoreceptors, organic field quench devices (O-FQDs), light-emitting electrochemical cells (LECs), organic laser diodes (O-lasers) and organic plasmon emitting devices, but preferably organic electro- luminescent devices (OLEDs), particularly preferably phosphorescent OLEDs.

The organic electroluminescent device contains a cathode, an anode and at least one emitting layer. In addition to these layers, it can contain further layers, for example one or more hole injection layers, hole transport layers, hole blocking layers, electron transport layers, electron injection layers, exciton blocking layers, electron blocking layers and/or charge generation layers. Interlayers can also be introduced between two emitting layers, which, for example, have an exciton blocking function. It should be noted, however, that not all of these layers necessarily have to be present. The organic electroluminescent device can contain one emitting layer, or it can contain several emitting layers. If several emitting layers are present, these preferably have a total of several emission maxima between 380 nm and 750 nm, so that overall white emission results, i.e. different emitting compounds that can fluoresce or phosphoresce are used in the emitting layers. Systems with three emitting layers are particularly preferred, with the three layers showing blue, green and orange or red emission. The organic electroluminescent device according to the invention can also be a tandem OLED, in particular for white-emitting OLEDs. The compound according to the invention can be used in different layers, depending on the precise structure.

In one embodiment of the invention, the compound according to the invention can be used in an emitting layer of an organic electroluminescent device as a matrix material for phosphorescent emitters or for emitters that exhibit TADF (thermally activated delayed fluorescence), in particular for phosphorescent emitters. The organic electroluminescent device can contain one emitting layer, or it can contain several emitting layers, where at least one emitting layer has at least one contains a compound according to the invention as a matrix material. The compounds according to the invention are particularly suitable as a matrix material for green, yellow, orange or red phosphorescent emitters.

In a further embodiment of the invention, the compound according to the invention can be used as a hole transport material or as an electron blocking material in a hole transport or electron blocking layer of an organic electroluminescent device. This applies in particular when both W together represent a group of the formula (2) and when all Xs represent CR.

In a further embodiment of the invention, the compound according to the invention can be used as an electron transport material in an electron transport layer or a hole blocking layer of an organic electroluminescent device. This applies in particular when at least one W stands for N.

If the compound according to the invention is used as a matrix material for a phosphorescent compound in an emitting layer, it is preferably used in combination with one or more phosphorescent materials (triplet emitters). Phosphorescence in the sense of this invention is understood to mean luminescence from an excited state with a higher spin multiplicity, i.e. a spin state > 1, in particular from an excited triplet state. In the sense of this application, all luminescent complexes with transition metals or lanthanides, in particular all iridium, platinum and copper complexes, are to be regarded as phosphorescent compounds.

The mixture of the compound according to the invention and the emitting compound contains between 99 and 1 vol. %, preferably between 98 and 10 vol. %, particularly preferably between 97 and 60 vol. %, in particular between 95 and 80 vol. %, of the compound according to the invention, based on the total mixture of emitter and matrix material. Accordingly, the mixture contains between 1 and 99 vol. %, preferably between 2 and 90 vol. %, particularly preferably between 3 and 40 vol.%, in particular between 5 and 20 vol.% of the emitter based on the total mixture of emitter and matrix material.

A further preferred embodiment of the present invention is the use of the compound according to the invention as a matrix material for a phosphorescent emitter in combination with a further matrix material. Suitable matrix materials which can be used in combination with the compounds according to the invention are aromatic ketones, aromatic phosphine oxides or aromatic sulfoxides or sulfones, e.g. according to WO 2004/013080, WO 2004/093207, WO 2006/005627 or WO 2010/006680, triarylamines, carbazole derivatives, e.g. B. CBP (N,N-biscarbazolylbiphenyl) or those in WO 2005/039246, US 2005/0069729, JP 2004/288381, EP 1205527, WO 2008/086851 or WO 2013/041176, indolocarbazole derivatives, e.g. according to WO 2007/063754 or WO 2008/056746, indenocarbazole derivatives, e.g. according to WO 2010/136109, WO 2011/000455, WO 2013/041176 or WO 2013/056776, azacarbazole derivatives, e.g. B. according to EP 1617710, EP 1617711, EP 1731584, JP 2005/347160, bipolar matrix materials, e.g. according to WO 2007/137725, silanes, e.g. according to WO 2005/111172, azaboroles or boronic esters, e.g. according to WO 2006/117052, triazine derivatives, e.g. according to WO 2007/063754, WO 2008/056746, WO 2010/015306, WO 2011/057706, WO 2011/060859 or WO 2011/060877, pyrimidine derivatives, zinc complexes, e.g. B. according to EP 652273 or WO 2009/062578, diazasilole or tetraazasilole derivatives, e.g. according to WO 2010/054729, diazaphosphole derivatives, e.g. according to WO 2010/054730, bridged carbazole derivatives, e.g. according to WO 2011/042107, WO 2011/060867, WO 2011/088877 and WO 2012/143080, triphenylene derivatives, e.g. according to WO 2012/048781, or dibenzofuran derivatives, e.g. B. according to WO 2015/169412, WO 2016/015810, WO 2016/023608, WO 2017/148564 or WO 2017/148565. Likewise, a further phosphorescent emitter which emits at a shorter wavelength than the actual emitter can be present in the mixture as a co-host or a compound which does not participate or does not participate to a significant extent in the charge transport, as described for example in WO 2010/108579. The compounds according to the invention are generally electron-rich or hole-transporting compounds. This applies in particular when both W together represent a group of formula (2) or when all W represent CR. Preferred co-matrix materials are therefore selected from the group of electron-transporting compounds, which are preferably triazine, pyrimidine, quinazoline and quinoxaline derivatives.

Particularly suitable matrix materials which are advantageously combined with the compounds according to the invention in a mixed matrix system can be selected from the compounds of the formulas (eTMM1), (eTMM2), (eTMM3), (eTMM4) or (eTMM5), as described below.

A further subject of the invention is therefore a mixture containing at least one compound according to the invention and at least one compound of the formulas (eTMM1), (eTMM2), (eTMM3), (eTMM4) and/or (eTMM5),

Formula (eTMM1 ),

Formula (eTMM2), Formula (eTMM3),

Formula (eTMM4),

Formula (eTMM5), where the symbols and indices used are:

L ² is, identically or differently at each occurrence, a single bond or an aromatic or heteroaromatic ring system having 5 to 24 ring atoms, each of which may be substituted by one or more radicals R ⁷ ;

R# is, identically or differently at each occurrence, D, F, CN or an aromatic ring system having 6 to 24 ring atoms which may be substituted by one or more radicals R ⁶ ;

Y is the same or different at each occurrence and is N or CR ⁷ , whereby it is excluded that two adjacent Ys simultaneously represent N;

V ² is 0 or S; R ⁶ is, on each occurrence, identical or different, H, D, F, CN, a straight-chain alkyl group having 1 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where the alkyl, alkenyl or alkynyl group may in each case be substituted by one or more radicals R ⁷ and where one or more non-adjacent CH2 groups may be replaced by Si(R ⁷ )2, C=O, NR ⁷ , O, S or CONR ⁷ , or an aromatic or heteroaromatic ring system having 5 to 60 ring atoms, which may in each case be substituted by one or more radicals R ⁷ ; two radicals R ⁶ can also form an aromatic, heteroaromatic, aliphatic or heteroaliphatic ring system with one another;

Ar ⁵ represents, identically or differently at each occurrence, an aromatic or heteroaromatic ring system having 5 to 40 ring atoms which may be substituted by one or more radicals R ⁷ ;

R ⁷ is, identically or differently on each occurrence, H, D, F, CI, Br, I, N(R ⁸ ) ₂ , CN, NO ₂ , OR ⁸ , SR ⁸ , Si(R ⁸ ) ₃ , B(OR ⁸ ) ₂ , C(=O)R ⁸ , P(=O)(R ⁸ ) ₂ , S(=O)R ⁸ , S(=O)2R ⁸ , OSO2R ⁸ , a straight-chain alkyl group having 1 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where the alkyl, alkenyl or alkynyl group may each be substituted by one or more radicals R ⁸ , where one or more non-adjacent CH2 groups are replaced by Si(R ⁸ )2, C=O, NR ⁸ , O, S or CONR ⁸ , or an aromatic or heteroaromatic ring system having 5 to 40 ring atoms, each of which may be substituted by one or more radicals R ⁸ ; two or more radicals R ⁷ may form an aromatic, heteroaromatic, aliphatic or heteroaliphatic ring system with one another;

R ⁸ is at each occurrence, identically or differently, H, D, F or an aliphatic, aromatic or heteroaromatic organic radical, in particular a hydrocarbon radical having 1 to 20 C atoms, in which one or more H atoms can be replaced by F; b1 is 0, 1, 2, 3 or 4; b2 is 0, 1, 2 or 3.

The invention further relates to an organic electronic device, in particular an organic electroluminescent device comprising anode, cathode and at least one organic layer containing at least one light-emitting layer, wherein at least one light-emitting layer contains the above-mentioned mixture of at least one compound according to the invention and at least one compound of the formulas (eTMM1), (eTMM2), (eTMM3), (eTMM4) and/or (eTMM5).

Preferred compounds of the formula (eTMM1 ) are the compounds of the formulas (eTMMIa), (eTMMI b), (eTMMIc), (eTMMId) and (eTMMIe),

where the symbols and indices for these formulas have the following meaning:

W, W ¹ mean at each occurrence, identically or differently, O, S, C(R ^W ) ₂ or N-Ar ⁵ ;

R ^w is, identically or differently on each occurrence, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where one or more H atoms may be replaced by D, F or CN, or an aromatic or heteroaromatic ring system having 5 to 40 ring atoms which may be replaced by one or more substituents selected from D, F, CN, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where one or more H atoms of the alkyl group on the aromatic or heteroaromatic ring system may be replaced by D, F or CN; the two radicals R ^w which are bonded to the same carbon atom can also form a ring system with one another;

A is the same or different at each occurrence and is CR ⁷ or N, where a maximum of two A groups per cycle stand for N and where A stands for C when L ² is bonded to this position; a3 is the same or different on each occurrence and is 0, 1, 2, 3 or 4; b3 is the same or different on each occurrence and is 0, 1, 2 or 3; Ring B is derived from an aryl group having 6 to 20 ring atoms, which may be substituted by one or more R# substituents; Ring C is or ; L3 is an aromatic ring system having 6 to 40 ring atoms or a heteroaromatic ring system having 5 to 40 ring atoms, which may be substituted by one or more ^R7 radicals; and where ^L2 , X, Ar5, ^R7 and R# have the meanings given above. Preferred compounds of the formula (eTMM3) are the compounds of the formula (8a), formula (eTMM3a) where the symbols and indices for this formula (eTMM3a) have the following meaning: W ¹ is, identically or differently at each occurrence, O, S, C(R ^W ) 2 or N-Ar ⁵ ; #X is CR or NAr ⁵ , preferably NAr ⁵ ; R ^W is, on each occurrence, the same or different, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where one or more H atoms may be replaced by D, F or CN, or an aromatic or heteroaromatic ring system having 5 to 40 ring atoms which may be replaced by one or more substituents selected from D, F, CN, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where one or more H atoms of the alkyl group on the aromatic or heteroaromatic ring system may be replaced by D, F or CN; a3 is, on each occurrence, the same or different, 0, 1, 2, 3 or 4; Ring B is derived from an aryl group having 6 to 20 ring atoms, which may be substituted by one or more substituents R##; Ring C is or ; where L ² , Ar ⁵ and R# have the meanings given above. In compounds of the formula (eTMM1a), W is preferably O or N-Ar ⁵ . In compounds of the formula (eTMM1a), A is preferably CR ⁷ , identically or differently on each occurrence, where A is C when L ² is bonded to this position. In compounds of the formula (eTMM1d) or (eTMM3a), W ¹ is preferably O, C(R ^W ) 2 or N-Ar ⁵ , particularly preferably N-Ar ⁵ . In compounds of the formula (eTMM1e), L ³ is preferably a heteroaromatic ring system having 9 to 30 ring atoms, which may be substituted by one or more radicals R ⁷ . In a preferred embodiment of the compounds of the formulas (eTMM1), (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d), (eTMM1e), (eTMM2), (eTMM3), (eTMM3a), (eTMM4) or (eTMM5), which can be combined according to the invention with the above-mentioned compounds according to the invention, as described above, R ⁷ is selected, identically or differently on each occurrence, from the group consisting of H, D, F, CN, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where the alkyl group can be substituted in each case by one or more radicals R ⁸ , or an aromatic or heteroaromatic ring system having 5 to 60 ring atoms, preferably having 5 to 40 ring atoms, each of which is substituted by one or more radicals R ⁸ can be substituted. In a particularly preferred embodiment of the compounds of the formulas (eTMM1), (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d), (eTMM1e), (eTMM2), (eTMM3), (eTMM3a), (eTMM4) or (eTMM5), which can be combined according to the invention with the above-listed compounds according to the invention, as described above, R ⁷ is the same or different on each occurrence and is selected from the group consisting of H, D or an aromatic or heteroaromatic ring system having 6 to 30 ring atoms, which can be substituted by one or more radicals R ⁸ . The preparation of the compounds of formulas (eTMM1), (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d), (eTMM1e), (eTMM2), (eTMM3), (eTMM3a), (eTMM4) or (eTMM5) are generally known and some of the compounds are commercially available. Suitable compounds of the formula (eTMM1) are known, for example, from the following publications: WO2007/077810A1, WO2008/056746A1, WO2010/136109A1, WO2011/057706A2, WO2011/160757A1, WO2012/023947A1, WO2012/048781A1, WO2013/077352A1, WO2013147205A1, WO2013/083216A1, WO2014/094963A1, WO2014/007564A1, WO2014/015931A1, WO2015/090504A2, WO2015/105251A1, WO2015/169412A1, WO2016/015810A1, WO2016/013875A1, WO2016/010402A1, WO2016/033167A1, WO2017/178311A1, WO2017/076485A1, WO2017/1867 60A1, WO2018/004096A1, WO2018/016742A1, WO2018/123783A1, WO2018/159964A1, WO2018/174678A1, WO2018/174679A1, WO2018/174681A1, 174682A1, WO2019/177407A1, WO2019/245164A1, WO2019/240473A1, WO2019/017730A1, WO2019/017731A1, WO2019/017734A1, WO2019/145316A1, WO2019/1214 58A1, WO2020/130381A1, WO2020/130509A1, WO2020/169241A1, WO2020/141949A1, WO2021/066623A1, WO2021/101220A1, WO2021/037401A1, 180614A1, WO2021/239772A1, WO2022/015084A1, WO2022/025714A1, WO2022/055169A1, EP3575296A1, EP3591728A1, US2014/0361254A1, US2014/0361268A1, KR20210036304A, KR20210036857A, KR2021147993A, JP2011/160367A2 and JP2017/107992A2. Suitable compounds of the formula (eTMM2) are known, for example, from the following publications: WO2015/182872A1, WO2015/105316A1, WO2017/109637A1, WO2018/060307A1, WO2018/151479A2, WO2018/088665A2, WO2018/060218A1, WO2018/234932A1, WO2019/058200A1, WO2019/017730A1, WO2019/017731A1, WO2019/066282A1, WO2019/059577A1, WO2020/141949A1, WO2020/067657A1, WO2022063744A1, WO2022/090108A1, WO2022/207678A1, KR2019035308A, KR2021147993A, CN110437241A, US2016/072078A1. Suitable compounds of the formula (eTMM3) are known, for example, from the following publications: WO2017/160089A1, WO2019/017730A1, WO2019/017731A1, WO2020/032424A1. Suitable compounds of the formula (eTMM5) are known, for example, from the following publications: WO2015/093878A1, WO2016/033167A1, WO2017/183859A1, WO2017/188655A1, WO2018/159964A1. For a combination with the compounds according to the invention, as described above or preferably described, compounds of the formulas (eTMM1), (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d), (eTMM1e) and/or (eTMM2) are particularly suitable, as described above or preferably described, or corresponding compounds from the tables below which fall under these formulas. The compounds of the formulas (eTMM1), (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d) and/or (eTMM1e) are particularly preferred. Further examples of suitable host materials of the formulas (eTMM1), (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d), (eTMM1e), (eTMM2), (eTMM3), (eTMM3a), (eTMM4) or (eTMM5), which can be combined according to the invention with the above-listed compounds of the invention, as described above, are the structures listed below in Tables 1 and 2 below. Table 1:

Particularly suitable compounds of the formulas (eTMM1), (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d), (eTMM1e) and/or (eTMM2), which can be combined according to the invention with the above-listed compounds of the invention, as described above, and are used in the electroluminescent device or mixture according to the invention, are the compounds E1 to E40 of Table 2. Table 2:

The above-mentioned host materials according to the invention and their preferred embodiments can be combined in the device according to the invention with any of the above-mentioned matrix materials/host materials, the matrix materials/host materials of the formulas (eTMM1), (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d), (eTMMI e), (eTMM2), (eTMM3), (eTMM3a), (eTMM4) or (eTMM5), as well as their preferred embodiments described in Table 1 or the compounds E1 to E40 in Table 2.

If the matrix material is a deuterated compound, it is possible that the matrix material is a mixture of deuterated compounds with the same basic chemical structure, which differ only in the degree of deuteration.

In a preferred embodiment of the matrix material, this is a mixture of deuterated compounds according to the invention or of the formula (eTMM1), (eTMMI a), (eTMMI b), (eTMMI c), (eTMMI d), (eTMMI e), (eTMM2), (eTMM3), (eTMM3a), (eTMM4) or (eTMM5), as described above, wherein the degree of deuteration of these compounds is at least 50% to 90%, preferably 70% to 100%. Corresponding deuteration methods are known to the person skilled in the art and are described, for example, in KR2016041014, WO2017/122988, KR202005282, KR101978651 and WO2018/110887 or in Bulletin of the Chemical Society of Japan, 2021 , 94(2), 600-605 or Asian Journal of Organic Chemistry, 2017, 6(8), 1063-1071.

A suitable method for deuterating a compound by exchanging one or more H atoms for D atoms is to treat the compound to be deuterated in the presence of a platinum catalyst or palladium catalyst and a deuterium source. The term "deuterium source" means any compound that contains one or more D atoms and can release them under suitable conditions.

The platinum catalyst is preferably dry platinum on carbon, preferably 5% dry platinum on carbon. The palladium catalyst is preferably dry palladium on carbon, preferably 5% dry palladium on carbon. A suitable deuterium source is D2O, benzene-d6, chloroform-d, acetonitrile-d3, acetone-d6, acetic acid-d4, methanol-d4 or toluene-d8. A preferred deuterium source is D2O or a combination of D2O and a fully deuterated organic solvent. A particularly preferred deuterium source is the combination from D2O with a fully deuterated organic solvent, whereby the fully deuterated solvent is not limited here. Particularly suitable fully deuterated solvents are benzene-d6 and toluene-d8. A particularly preferred deuterium source is a combination of D2O and toluene-d8. The reaction is preferably carried out with heating, more preferably with heating to temperatures between 100 °C and 200 °C. Furthermore, the reaction is preferably carried out under pressure.

The concentration of the sum of all host materials according to the invention, as described above or preferably described, in the mixture according to the invention or in the light-emitting layer of the device according to the invention is usually in the range from 5 wt.% to 90 wt.%, preferably in the range from 10 wt.% to 85 wt.%, more preferably in the range from 20 wt.% to 85 wt.%, even more preferably in the range from 30 wt.% to 80 wt.%, very particularly preferably in the range from 20 wt.% to 60 wt.% and most preferably in the range from 30 wt.% to 50 wt.%, based on the entire mixture or based on the entire composition of the light-emitting layer.

The concentration of the sum of all host materials of the formulas (eTMM1), (eTMMI a), (eTMMI b), (eTMMI c), (eTMMI d), (eTMMI e), (eTMM2), (eTMM3), (eTMM3a), (eTMM4) or (eTMM5), as previously described or preferably described, in the mixture according to the invention or in the light-emitting layer of the device according to the invention is usually in the range from 5 wt. % to 90 wt. %, preferably in the range from 10 wt. % to 85 wt. %, more preferably in the range from 20 wt. % to 85 wt. %, even more preferably in the range from 30 wt. % to 80 wt. %, very particularly preferably in the range from 20 wt. % to 60 wt. % and most preferably in the range from 30 wt. % to 50 wt. %, based on the entire mixture or based on the entire composition of the light-emitting layer.

The present invention also relates to a mixture which, in addition to the above-mentioned host materials according to the invention and the Host material of at least one of the formulas (eTMM1), (eTMMIa), (eTMMI b), (eTMMIc), (eTMMId), (eTMMIe), (eTMM2), (eTMM3), (eTMM3a), (eTMM4) or (eTMM5), as previously described or preferably described, contains at least one phosphorescent emitter.

Particularly suitable phosphorescent compounds (= triplet emitters) are compounds which emit light, preferably in the visible range, when suitably excited and which also contain at least one atom with an atomic number greater than 20, preferably greater than 38 and less than 84, particularly preferably greater than 56 and less than 80, in particular a metal with this atomic number. Preferably used as phosphorescent emitters are compounds which contain copper, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, iridium, palladium, platinum, silver, gold or europium, in particular compounds which contain iridium or platinum.

Examples of the emitters described above can be found in applications WO 00/70655, WO 2001/41512, WO 2002/02714, WO 2002/15645, EP 1191613, EP 1191612, EP 1191614, WO 2005/033244, WO 2005/019373, US 2005/0258742, WO 2009/146770, WO 2010/015307, WO 2010/031485, WO 2010/054731, WO 2010/054728, WO 2010/086089, WO 2010/099852, WO 2010/102709, WO 2011/032626, WO 2011/066898, WO 2011/157339, WO 2012/007086, WO 2014/008982, WO 2014/023377, WO 2014/094961, WO 2014/094960, WO 2015/036074, WO 2015/104045, WO 2015/117718, WO 2016/015815, WO 2016/124304, WO 2017/032439, WO 2018/011186 and WO 2018/041769, WO 2019/020538, WO 2018/178001, WO 2019/115423 and WO 2019/158453. In general, all phosphorescent complexes as used in accordance with the prior art for phosphorescent OLEDs and as known to the person skilled in the art in the field of organic electroluminescence are suitable, and the person skilled in the art can use further phosphorescent complexes without inventive step.

Examples of phosphorescent dopants are listed below.

In the further layers of the organic electroluminescent device according to the invention, all materials can be used as are usually used according to the prior art. The person skilled in the art can therefore use all materials known for organic electroluminescent devices in combination with the compounds according to the invention without inventive step.

Particularly suitable for use in layers with hole-transporting function of any OLEDs, not only OLEDs according to the definitions of the present application, are the following compounds (HT-1) to (HT-20):

The term “layers with hole-transporting function” refers in particular to hole injection layers, hole transport layers, electron blocking layers and also emitting layers, in particular hole injection layers, hole transport layers and electron blocking layers.

The compounds (HT-1) to (HT-20) are generally suitable for use in hole-transporting layers. Their use is not limited to specific OLEDs, such as the OLEDs described in the present application.

The compounds (HT-1) to (HT-20) can be prepared according to the instructions disclosed in the published patent applications listed in the table above. The further teaching concerning the use and preparation of the compounds disclosed in the published patent applications listed in the table above is hereby explicitly included and is preferably to be combined with the above-mentioned teaching on the use of the above-mentioned compounds as hole-transporting materials. The compounds (HT-1) to (HT-20) show excellent properties when used in OLEDs, in particular excellent service life and efficiency. Also preferred is an organic electroluminescent device, characterized in that one or more layers are coated using a sublimation process. The materials are vapor-deposited in vacuum sublimation systems at an initial pressure of less than 10 ^-5 mbar, preferably less than 10 ^-6 mbar. However, it is also possible for the initial pressure to be even lower, for example less than 10 ^-7 mbar. Also preferred is an organic electroluminescent device, characterized in that one or more layers are coated using the OVPD (Organic Vapour Phase Deposition) process or with the aid of carrier gas sublimation. The materials are applied at a pressure between 10 ^-5 mbar and 1 bar. A special case of this process is the OVJP (Organic Vapour Jet Printing) process, in which the materials are applied directly through a nozzle and thus structured. Also preferred is an organic electroluminescent device, characterized in that one or more layers are produced from solution, such as by spin coating, or with any printing process, such as screen printing, flexographic printing, offset printing, LITI (Light Induced Thermal Imaging, thermal transfer printing), ink-jet printing or nozzle printing. Soluble compounds are required for this, which are obtained, for example, by suitable substitution. Hybrid processes are also possible, in which, for example, one or more layers are applied from solution and one or more further layers are vapor-deposited. These processes are generally known to the person skilled in the art and can be applied by him without inventive step to electronic devices, in particular organic electroluminescent devices containing the compounds according to the invention according to formula (1).

The compounds according to the invention and the electronic devices according to the invention, in particular the organic electroluminescent devices, are characterized by one or more of the following surprising advantages over the prior art:

1. OLEDs containing the compounds according to the invention as matrix material for phosphorescent emitters lead to long lifetimes.

2. OLEDs containing the compounds according to the invention lead to high efficiencies. This is particularly true when the compounds are used as matrix material for a phosphorescent emitter.

3. OLEDs containing the compounds according to the invention lead to low operating voltages. This applies in particular when the compounds are used as matrix material for a phosphorescent emitter.

The invention is explained in more detail by the following examples, without intending to limit it thereby. The person skilled in the art can use the descriptions to implement the invention in the entire disclosed area and produce further electronic devices according to the invention without inventive step.

Examples:

Unless otherwise stated, the following syntheses are carried out under a protective gas atmosphere in dried solvents. The solvents and reagents can be obtained from Sigma-ALDRICH or ABCR, for example. The respective information in square brackets or the information given for individual compounds Numbers refer to the CAS numbers of the compounds known from the literature. For compounds that can have several enantiomeric, diastereomeric or tautomeric forms, one form is shown as a representative.

A) Synthesis of synthons S:

Example S1:

A well-stirred solution of 38.4 g (100 mmol) 6-bromo-13,14-dihydro-carbazolo[1,2-a]carbazole [2271382-95-5], 21.8 g (110 mmol) biphenyl-2-boronic acid [914675-52-8], 42.4 g (200 mmol) tripotassium phosphate [7778-53-2], 1.16 g (1 mmol) tetrakis(triphenylphosphine)palladium(0) [14221-01-3], 300 ml toluene, 100 ml dioxane and 300 ml water is heated under reflux for 16 h. After cooling, the organic phase is separated, washed three times with 300 ml of water each time, once with 300 ml of saturated sodium chloride solution and dried over magnesium sulfate. The drying agent is filtered off, the filtrate is evaporated to dryness and the residue is chromatographed (Torrent column machine from A. Semrau). Yield: 34.5 g (75 mmol) 75%; Purity: approx. 98% according to ¹ H-NMR.

The following compounds can be prepared analogously by adjusting the stoichiometry of the reactants, whereby when chlorides are used instead of tetrakis(triphenylphosphine)-palladium(0), 224 mg (1 mmol) of palladium acetate and 821 mg (2 mmol) of S-Phos [657408-07-6] are used.

Example S100:

Procedure analogous to the synthesis of 3c in T. Taisei et al., Chem. Lett., 2019, 48, 1160. Preparation: 38.4 g (100 mmol) 6-bromo-13,14-dihydro-carbazolo[1,2-a]carbazole [2271382-95-5] and 26.7 g (110 mmol) 3-phenyl-9H-carbazole [103012-26-6]. The crude product is purified chromatographically. Yield: 17.0 g (31 mmol), 31%; Purity: approx. 98% according to ¹ H NMR.

The following compounds can be prepared analogously by adjusting the stoichiometry of the reactants.

B) Synthesis of the examples according to the invention:

Example B1 :

A well-stirred suspension of 30.6 g (100 mmol) of 13,14-dihydrocarbazolo[1,2-a]carbazole [1444018-85-2] in 1000 ml of diethyl ether is mixed with 80 ml (200 mmol) of n-butyllithium, 2.5 molar in n-hexane, at room temperature while stirring. After the addition is complete and the exothermic reaction has subsided, the mixture is stirred for 1 h and then a mixture of 8.5 g (50 mmol) of silicon tetrachloride [10026-04-7] and 100 ml of diethyl ether is added dropwise. After the addition is complete and the exothermic reaction has subsided, the mixture is stirred for 5 hours under reflux, then the diethyl ether is removed in vacuo, the residue is taken up in approx. 300 ml of dichloromethane (DCM) and chromatographed on aluminum oxide, basic, activity level 1. Further purification of the crude product is carried out by chromatography and/or repeated hot extraction crystallization (usual organic solvents or combinations thereof, preferably acetonitrile-DCM, 1:3 to 3:1 vv), as well as Fractional sublimation or annealing in high vacuum. Yield:

22.2 g (70 mmol), 70%; Purity: approx. 99.9% according to HPLC.

Analogously, the following compounds can be obtained by adjusting the stoichiometry of the reactants.

Example: Production of OLEDs

The production of OLEDs according to the invention as well as OLEDs according to the prior art is carried out according to a general process according to WO 2004/058911, which is adapted to the conditions described here (layer thickness variation, materials used). The following examples present the results of various OLEDs. Cleaned glass plates (cleaned in a Miele laboratory dishwasher, Merck Extran cleaner) coated with structured ITO (indium tin oxide) with a thickness of 50 nm are pretreated with UV ozone for 25 minutes (UV ozone generator PR-100, UVP). These coated glass plates form the substrates onto which the OLEDs are applied. a) Blue fluorescence OLED components - BF

The compounds according to the invention can be used in the hole injection layer (HIL), hole transport layer (HTL) and/or in the electron blocking layer (EBL). All materials are thermally vapor-deposited in a vacuum chamber. The emission layer (EML) always consists of at least one matrix material (host material) SMB (see Table 1) and an emitting dopant (dopant, emitter) D, which is mixed into the matrix material or materials by co-evaporation in a certain volume proportion. A specification such as SMB:D (97:3%) means that the material SMB is present in the layer in a volume proportion of 97% and the dopant D in a volume proportion of 3%. Analogously, the electron transport layer can also consist of a mixture of two materials (see Table 1). The materials used to produce the OLEDs are shown in Table 5.

The OLEDs are characterized as standard. For this purpose, the electroluminescence spectra, the current efficiency (measured in cd/A), the power efficiency (measured in Im/W) and the external quantum efficiency (EQE, measured in percent) are determined as a function of the luminance, calculated from current-voltage-luminance characteristics (IUL characteristics) assuming a Lambertian radiation characteristic. The EQE in (%) and the voltage in (V) are specified at a luminance of 1000 cd/m ² .

The OLEDs have the following layer structure:

Substrat Hole injection layer (HIL) made of HTM1 doped with 5% NDP-9 (commercially available from Novaled), 20 nm Hole transport layer (HTL), see Table 1 Electron blocking layer (EBL), see Table 1 Emission layer (EML), see Table 1 Electron transport layer (ETL), see Table 1 Electron injection layer (EIL) made of ETM2, 1 nm Cathode made of aluminum, 100 nm.

Table 1: Structure of blue fluorescent OLED components

Table 2: Results of blue fluorescent OLED devices

b) Phosphorescent OLED devices

The compounds according to the invention can be used in the hole injection layer (HIL), the hole transport layer (HTL), the electron blocking layer (EBL) and/or in the emission layer (EML) as matrix material (host material) M (see Table 5). For this purpose, all materials are thermally vapor-deposited in a vacuum chamber. The emission layer always consists of at least one or more matrix materials M and a phosphorescent dopant Ir, which is mixed into the matrix material or materials by co-evaporation in a certain volume proportion. A specification such as M1:M2:lr (55%:35%:10%) means that the material M1 is present in the layer in a volume proportion of 55%, M2 in a volume proportion of 35% and Ir in a volume proportion of 10%. Analogously, the electron transport layer can also consist of a mixture of two materials. The exact structure of the OLEDs can be found in Table 3. The materials used to fabricate the OLEDs are shown in Table 5.

The OLEDs have the following layer structure:

Substrat

Hole injection layer (HIL) made of HTM1 doped with 5% NDP-9 (commercially available from Novaled), 20 nm Hole transport layer (HTL), see Table 3 Electron blocking layer (EBL), see Table 3 Emission layer (EML), see Table 3 Hole blocking layer (HBL), see Table 3 Electron transport layer (ETL), made of ETMTETM2 (50%:50%), 30 nm Electron injection layer (EIL) made of ETM2, 1 nm. Cathode made of aluminum, 100 nm.

Table 3: Structure of phosphorescent OLED components

Table 4: Results of phosphorescent OLED devices

Table 5: Structural formulas of the materials used

Claims

Patent claims

1 . A compound containing a partial structure according to formula (1 ),

X

II

X

Formula (1) where the symbols used are:

M is Si, Ge, Sn, Ti, Zr or Hf;

W is the same or different at each occurrence CR or N, where a maximum of one W stands for N per cycle; or the two W together form a group of the formula (2),

Formula (2) where one of the two dashed bonds represents the bond to N and the other dashed bond represents the bond to Z;

Z is, identical or different at each occurrence, a single bond, BR, CR ₂ , C=O, SiR ₂ , GeR ₂ , NR, P(=O)R, O, S or SO ₂ ;

Y is the same or different at each occurrence and is NR, 0 or S; or Y together with the explicitly drawn carbon atom and the adjacent X forms a group according to formula (3) or (4), Formula (3) Formula (4) where W, Z and X have the meanings given above, the dashed bond marked with * represents the bond to M and the two other dashed bonds represent the linkage of the structure within the formula (1);

X is the same or different at each occurrence and is CR or N, where a maximum of two Xs per cycle stand for N, or two adjacent Xs in formula (2) together stand for CR2, NR, O or S;

R is, identically or differently on each occurrence, H, D, F, CI, Br, I, N(Ar) ₂ , N(R ¹ ) ₂ , OAr, SAr, CN, NO2, OR ¹ , SR ¹ , COOR ¹ , C(=O)N(R ¹ ) ₂ , Si(R ¹ ) ₃ , B(OR ¹ ) ₂ , C(=O)R ¹ , P(=O)(R ¹ ) ₂ , S(=O)R ¹ , S(=O)2R ¹ , OSO2R ¹ , a straight-chain alkyl group having 1 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where the alkyl, alkenyl or alkynyl group in each case can be substituted by one or more radicals R ¹ , where one or more non-adjacent CH2 groups can be replaced by Si(R ¹ ) 2, C=O, NR ¹ , O, S or CONR ¹ , or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which can be substituted by one of the several radicals R ¹ ; two radicals R can also form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system with one another;

Ar is, identically or differently at each occurrence, an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which may be substituted by one or more radicals R ¹ ; R ¹ is, identically or differently on each occurrence, H, D, F, CI, Br, I, N(R ² ) ₂ , CN, NO2, OR ² , SR ² , Si(R ² ) ₃ , B(OR ² ) ₂ , C(=O)R ² , P(=O)(R ² ) ₂ , S(=O)R ² , S(=O) ₂ R ² , OSO2R ² , a straight-chain alkyl group having 1 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where the alkyl, alkenyl or alkynyl group may each be substituted by one or more radicals R ² , where one or more non-adjacent CH2 Groups can be replaced by Si(R ² ) 2, C=O, NR ² , O, S or CONR ² and where one or more H atoms in the alkyl, alkenyl or alkynyl group can be replaced by D, F, CI, Br, I or CN, or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, each of which can be substituted by one or more radicals R ² ; two or more radicals R ¹ can form an aliphatic, aromatic or heteroaromatic ring system with one another;

R ² is, identically or differently at each occurrence, H, D, F, CN or an aliphatic, aromatic or heteroaromatic organic radical, in particular a hydrocarbon radical, having 1 to 20 C atoms, in which one or more H atoms may be replaced by F.

2. A compound according to claim 1, selected from the compounds of formula (5) or formula (6),

Formula (5) Formula (6) where the symbols used have the meanings given in claim 1 and furthermore: R ^M is on each occurrence, identically or differently, F, CN, OR ¹ , OAr, N(R ¹ ) 2, NAr2, Si(R ¹ ) 3, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where the alkyl or alkoxy group may in each case be substituted by one or more radicals R ¹ and where one or more non-adjacent CH 2 groups may be replaced by Si(R ¹ ) 2, C=O, NR ¹ , O, S or CONR ¹ , or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which may be substituted by one of the several radicals R ¹ ; Two R ^M radicals can also form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system with one another, where the linking of the two R ^M radicals can take place either by a single bond or by a group selected from C(R ¹ ) 2, O, S, NR ¹ or BR; furthermore, one or more R ^{M radicals} can be linked to one or more R to form a ring system.

3. A compound according to claim 1 or 2, characterized in that Y, identical or different on each occurrence, represents NR or that Y together with the explicitly drawn carbon atom and the adjacent X forms a group according to formula (3).

4. A compound according to one or more of claims 1 to 3, characterized in that the partial structure of formula (1) is selected from the structures according to formulas (7) and (8), where the symbols used have the meanings given in claim 1 and Y in formula (8) stands for NR, O or S.

5. A compound according to one or more of claims 1 to 4, selected from the compounds of the formulae (9), (10), (11) and (12), wherein the symbols used have the meanings given in claims 1 and 2 and Y in the formulae (10) and (12) is NR, O or S.

6. A compound according to one or more of claims 1 to 5, characterized in that Z, identical or different on each occurrence, represents a single bond, CR2, BR or O.

7. A compound according to one or more of claims 1 to 6, characterized in that both groups W together represent a group of formula (2a),

or that Z stands for a single bond and in the same cycle one of the two groups W stands for CR and the other of the two groups W stands for N.

8. A compound according to one or more of claims 1 to 7, characterized in that the partial structure of formula (1) is selected from the structures of formulas (7a), (7b), (8a) and (8b),

wherein the symbols used have the meanings given in claim 1, Y in the formulas (8a) and (8b) stands for NR, O or S and Z in the formulas (7a) and (8a) preferably stands for a single bond.

9. A compound according to one or more of claims 1 to 8, selected from the compounds of formulas (9a), (9b), (10a), (10b), (11a), (11b), (12a) and (12b),

Formula (9b)

Formula (10b)

Formula (11b)

Formula (11a)

Formula (12a) Formula (12b) wherein the symbols used have the meanings given in claims 1 and 2, Y in the formulas (10a), (10b), (12a) and (12b) stands for NR, O or S and Z in the formulas (9a), (10a), (11a) and (12a) preferably stands for a single bond.

10. A compound according to one or more of claims 1 to 9, selected from the compounds of formulas (9a-1), (10a-1), (11a-1) and (12a-1),

Formula (9a-1) Formula (10a-1)

Formula (11 a-1 ) Formula (12a-1) wherein the symbols have the meanings given in claims 1 and 2, Y in the formulas (1 Oa-1 ) and (12a-1 ) stands for NR, O or S and Z preferably stands for a single bond.

11. A compound according to one or more of claims 1 to 10, characterized in that M stands for Si or Ge, preferably Si.

12. A compound according to one or more of claims 1 to 11, characterized in that the compound has not more than four substituents R bonded to C atoms which are different from H or D.

13. Compound according to one or more of claims 1 to 12, characterized in that R ^M is selected on each occurrence, identically or differently, from the group consisting of a straight-chain alkyl group having 1 to 6 C atoms or a branched or cyclic alkyl group having 3 to 6 C atoms, where in the alkyl group one or more H atoms can be replaced by D, or an aromatic or heteroaromatic tic ring system with 6 to 13 aromatic ring atoms, which can be substituted by one or more radicals R ¹ ; the two radicals R ^M can also form a ring system with each other; or the two groups R ^M together represent a group of the formula (13),

Formula (13) wherein the dashed bonds represent the bonds to M and R ¹ has the meanings given in claim 1.

14. Formulation comprising at least one compound according to one or more of claims 1 to 13 and at least one further compound, wherein the further compound is a further matrix material and/or a phosphorescent emitter and/or a fluorescent emitter and/or an emitter which exhibits thermally activated delayed fluorescence and/or a solvent.

15. Use of a compound according to one or more of claims 1 to 13 in an electronic device.

16. Electronic device comprising one or more compounds according to one or more of claims 1 to 13.

17. Electronic device according to claim 16, which is an organic electroluminescent device, characterized in that the compound according to one or more of claims 1 to 13 is used in an emitting layer as a matrix material for phosphorescent emitters or for emitters which exhibit TADF (thermally activated delayed fluorescence), or as a hole transport material or as an electron blocking material in a hole transport or electron blocking layer or as an electron transport material in an electron transport layer or a hole blocking layer.

18. Mixture containing at least one compound according to one or more of claims 1 to 13 and at least one compound according to formula (eTMM1), (eTMM2), (eTMM3), (eTMM4) or (eTMM5),

Formula (eTMM1 ),

Formula (eTMM2),

Formula (eTMM4),

where the symbols and indices used are:

V ² is 0 or S;

R ⁶ is, identically or differently on each occurrence, H, D, F, CN, a straight-chain alkyl group having 1 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where the alkyl, alkenyl or alkynyl group may in each case be substituted by one or more radicals R ⁷ and where one or more non-adjacent CH2 groups may be replaced by Si(R ⁷ )2, C=O, NR ⁷ , O, S or CONR ⁷ , or an aromatic or heteroaromatic ring system having 5 to 60 ring atoms, which may in each case be substituted by one or more radicals R ⁷ ; two radicals R ⁶ can also form an aromatic, heteroaromatic, aliphatic or heteroaliphatic ring system; Ar ⁵ represents, identically or differently at each occurrence, an aromatic or heteroaromatic ring system having 5 to 40 ring atoms, which may be substituted by one or more radicals R ⁷ ;

R ⁷ is, identically or differently on each occurrence, H, D, F, CI, Br, I, N(R ⁸ ) ₂ , CN, NO ₂ , OR ⁸ , SR ⁸ , Si(R ⁸ ) ₃ , B(OR ⁸ ) ₂ , C(=O)R ⁸ , P(=O)(R ⁸ ) ₂ , S(=O)R ⁸ , S(=O) ₂ R ⁸ , OSO ₂ R ⁸ , a straight-chain alkyl group having 1 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where the alkyl, alkenyl or alkynyl group may each be substituted by one or more radicals R ⁸ , where one or more non-adjacent CH ₂ groups can be replaced by Si(R ⁸ ) ₂ , C=O, NR ⁸ , O, S or CONR ⁸ , or an aromatic or heteroaromatic ring system having 5 to 40 ring atoms, each of which can be substituted by one or more radicals R ⁸ ; two or more radicals R ⁷ can form an aromatic, heteroaromatic, aliphatic or heteroaliphatic ring system with one another;

R ⁸ is, identically or differently at each occurrence, H, D, F or an aliphatic, aromatic or heteroaromatic organic radical, in particular a hydrocarbon radical, having 1 to 20 C atoms, in which one or more H atoms may be replaced by F; b1 is 0, 1, 2, 3 or 4; b2 is 0, 1, 2 or 3.