WO2025181124A1 - Materials for organic electroluminescent devices - Google Patents

Abstract

The invention relates to materials that are suitable for use in electronic devices and to electronic devices, in particular organic electroluminescent devices, containing said materials.

Description

Materials for organic electroluminescent devices

The present invention relates to materials for use in electronic devices, in particular in organic electroluminescent devices, and to electronic devices, in particular organic electroluminescent devices, containing these materials.

In organic electroluminescent devices, phosphorescent organometallic complexes are often used as emitting materials. For quantum mechanical reasons, up to four times the energy and power efficiency is possible when using organometallic compounds as phosphorescence emitters. In general, there is still room for improvement in electroluminescent devices, especially in electroluminescent devices that exhibit triplet emission (phosphorescence). The properties of phosphorescent electroluminescent devices are not only determined by the triplet emitters used. The other materials used, such as matrix materials, are also of particular importance. Improvements to these materials can therefore also lead to significant improvements in the properties of the electroluminescent devices.

In addition to an emission layer, many electroluminescent devices comprise additional layers, such as 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. These layers have a significant impact on the performance of electroluminescent devices.

In addition, electroluminescent devices that use fluorescent emitters or emitters that exhibit TADF also face similar challenges. In general, there is still room for improvement in these materials, for example for use as matrix materials, particularly with regard to lifetime, but also with regard to the efficiency and operating voltage of the device.

The object of the present invention is therefore to provide compounds which are suitable for use in an organic electronic device, in particular in an organic electroluminescent device, and which, when used in this device, lead to good device properties, as well as to provide the corresponding electronic device.

In particular, the object of the present invention is to provide compounds that result in a long lifetime, good efficiency, and low operating voltage. In addition to the emitters, hole-conducting materials, hole-injection materials, electron-blocking materials, electron-injection materials, electron-transport materials, and hole-blocking materials contribute to these properties. Furthermore, the properties of the matrix materials, also referred to herein as host materials, also have a significant influence on the lifetime and efficiency of the organic electroluminescent device.

Furthermore, it is the object of the present invention to provide compounds which are characterized by a low refractive index (RI).

A further object of the present invention can be seen in providing compounds suitable for use in phosphorescent or fluorescent electroluminescent devices, in particular as matrix materials. In particular, it is an object of the present invention to provide matrix materials suitable for green or blue phosphorescent electroluminescent devices and, optionally, also for red or yellow phosphorescent electroluminescent devices. Furthermore, the compounds, particularly when used as emitter, host material, hole conductor material, hole injection material, electron blocking material, electron injection material, electron transport material or hole blocking material in organic electroluminescent devices, should lead to devices having excellent color purity.

Another task can be seen in providing electronic devices with excellent performance as cost-effectively as possible and in consistent quality

Furthermore, the electronic devices should be able to be used or adapted for a variety of purposes. In particular, the performance of the electronic devices should be maintained over a wide temperature range.

Surprisingly, it has been found that certain compounds, described in more detail below, solve this problem, are well suited for use in electroluminescent devices, and lead to organic electroluminescent devices that exhibit very good properties, particularly with regard to lifetime, color purity, efficiency, operating voltage, and refractive index. These compounds, as well as electronic devices, in particular organic electroluminescent devices, containing such compounds, are therefore the subject of the present invention.

The present invention relates to a compound according to formula (I), where the symbols are:

U is the same or different at each occurrence and is Ar or R ^b ; z is the same or different at each occurrence and is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17 or 18, preferably 0, 1, 2, 3 or 4, particularly preferably 0, 1 or 2;

Ar is, on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R other than H. Two radicals Ar which are bound to the same C atom may also be bridged to one another by a single bond or a bridge selected from B(R), C(R)2, Si(R)2, C=O, C=NR, C=C(R) ₂ , RC=CR, O, S, S=O, _SO2 , N(R), P(R), P(=O)R, an ortho-linked phenylene group which may be substituted by one or more radicals R other than H, preferably selected from C(R)2, O, N(R) and an ortho-linked phenylene group which may be substituted by one or more radicals R other than H. Preferably, Ar is, on each occurrence, identically or differently, an aryl or Heteroaryl group having 6 to 40 aromatic ring atoms, which may be substituted by one or more R radicals other than H, two Ar radicals which bond to the same C atom may also be bridged to one another by a single bond or a bridge selected from B(R), C(R)2, Si(R)2, C=O, C=NR, C=C(R)2, RC=CR, O, S, S=O, SO2, N(R), P(R), P(=O)R and an ortho-linked phenylene group which may be substituted by one or more R radicals other than H, preferably selected from C(R) ₂ , O, N(R) and an ortho-linked phenylene group which may be substituted by one or more R radicals other than H, the Ar radical may be coordinated to a transition metal; R ^a is, at each occurrence, identically or differently, H, D, F, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, each of which may be substituted by one or more radicals R ² other than H, preferably H, D, a straight-chain alkyl group having 1 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms, particularly preferably H or D;

R ^b is, identically or differently at each occurrence, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 20 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 C atoms, each of which may be substituted by one or more radicals R ² other than H, where the radical R ^b can form a ring system with the group U, preferably a straight-chain alkyl group having 1 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms, each of which may be substituted by one or more radicals R ² other than H;

R is, identically or differently at each occurrence, H, D, OH, F, CI, Br, I, CN, NO2, N(Ar') ₂ , N( ^R1 ) ₂ , C(=O)N(Ar') ₂ , C(=O)N( ^R1 ) ₂ , C(Ar') ₃ , C( ^R1 ) ₃ , Si(Ar') ₃ , Si( ^R1 ) ₃ , B(Ar') ₂ , B( ^R1 ) ₂ , C(=O)Ar', C(=O) ^R1 , P(=O)(Ar') ₂ , P(=O)( ^R1 ) ₂ , P(Ar') ₂ , P( ^R1 )2, S(=O)Ar', S(=O) ^R1 , S(=O)2Ar', S(=O) ^2R1 , OSO2Ar', OSO2R ¹ , a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms or an alkenyl or alkynyl group having 2 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 C atoms, where the alkyl, alkoxy, thioalkoxy, alkenyl or alkynyl group may each be substituted by one or more radicals R ¹ other than H, where one or more non-adjacent CH2 groups are substituted by R ¹ C=CR ¹ , C=C, Si(R ¹ )2, C=O, C=S, C=Se, C=NR ¹ , -C(=O)O-, -C(=O)NR ¹ -, NR ¹ , P(=O)(R ¹ ), -O-, -S-, SO or SO2, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, each of which may be substituted by one or more radicals R ¹ other than H, or an aryloxy or hetero- aryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R ¹ other than H, where two radicals R can also form a ring system with each other or a radical R can form a ring system with another group, in particular a group U or a radical R ^b , where the radical R can be coordinated to a transition metal;

Ar' is, on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms which may be substituted by one or more radicals R ¹ other than H, wherein two radicals Ar' which are bonded to the same C atom, Si atom, N atom, P atom or B atom may also be bridged to one another by a single bond or a bridge selected from B(R ¹ ), C(R ¹ ) ₂ , Si(R ¹ ) ₂ , C=O, C=NR ¹ , C=C(R ¹ ) ₂ , O, S, S=O, SO ₂ , N(R ¹ ), P(R ¹ ) and P(=O)R ¹ , wherein the radical Ar' may be coordinated to a transition metal;

R ¹ is, identically or differently on each occurrence, H, D, F, CI, Br, I, CN, NO 2, N(Ar”) ₂ , N(R ² ) ₂ , C(=O)Ar”, C(=O)R ² , P(=O)(Ar”) ₂ , P(Ar”) ₂ , B(Ar”) ₂ , B(R ² ) ₂ , C(Ar”) ₃ , C(R ² ) ₃ , Si(Ar”) ₃ , Si(R ² ) ₃ , a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 40 C atoms or an alkenyl group having 2 to 40 C atoms, each of which is substituted by one or more radicals R ² other than H may be substituted, where one or more non-adjacent CH2 groups may be replaced by ^-R2C = ^CR2- , -C=C-, Si( ^R2 )2, C=O, C=S, C=Se, C= ^NR2 , -C(=O)O-, -C(=O) ^NR2- , ^NR2 , P(=O)( ^R2 ), -O-, -S-, SO or SO2 and where one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO2, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, each of which may be substituted by one or more radicals ^R2 other than H, or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals ^R2 other than H, or an aralkyl or Heteroaralkyl group with 5 to 60 aromatic ring atoms, which can be substituted with one or several radicals R ² other than H, or a combination of these systems; two or more, preferably adjacent radicals R ¹ can form a ring system with each other, one or more radicals R ¹ can form a ring system with another part of the compound, the radical R ¹ can be coordinated to a transition metal;

Ar" is, on each occurrence, identical or different, an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, which may be substituted by one or more radicals R ² other than H, where two radicals Ar" which are bonded to the same C atom, Si atom, N atom, P atom or B atom may also be bridged to one another by a single bond or a bridge selected from B(R ² ), C(R ² ) 2, Si(R ² ) ₂ , C=O, C=NR ² , C=C(R ² ) ₂ , O, S, S=O, SO ₂ , N(R ² ), P(R ² ) and P(=O)R ² , where the radical Ar" may be coordinated to a transition metal;

R ² is selected, identically or differently at each occurrence, from the group consisting of H, D, F, CN, an aliphatic hydrocarbon radical having 1 to 20 C atoms or an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, in which one or more H atoms may be replaced by D, F, CI, Br, I or CN and which may be substituted by one or more alkyl groups each having 1 to 4 carbon atoms, wherein two or more, preferably adjacent, substituents R ² may form a ring system with one another.

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 3 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 defined as 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 by single bonds, such as biphenyl, are not referred to as aryl or heteroaryl groups, but rather as aromatic ring systems.

An electron-poor heteroaryl group within the meaning of the present invention is a heteroaryl group that has at least one heteroaromatic six-membered ring containing at least one nitrogen atom. Further aromatic or heteroaromatic five-membered rings or six-membered rings can be fused to this six-membered ring. Examples of electron-poor heteroaryl groups are pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, quinazoline, or quinoxaline.

An aromatic ring system within the meaning of this invention contains 6 to 60, preferably 6 to 40, carbon atoms in the ring system. An aromatic ring system within the meaning of this invention does not contain a heteroaryl group. A heteroaromatic ring system within the meaning of this invention contains 3 to 60 carbon atoms, preferably 3 to 40 carbon atoms, and at least one heteroaryl group, with the proviso that the sum of carbon atoms and heteroatoms is at least 5. The heteroatoms are preferably selected from N, O and/or S. An aromatic or heteroaromatic ring system within the meaning of this invention is to be understood as a system which does not necessarily contain only aryl or heteroaryl groups, but in which several aryl or heteroaryl groups can also be connected by a non-aromatic unit, such as a C, N or O atom. Likewise, this 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 also to be understood as aromatic ring systems within the meaning of this invention, as are systems in which two or more aryl groups are linked, for example, by a linear or cyclic alkyl group or by a silyl 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 each other, for example biphenyl, terphenyl, quaterphenyl or bipyridine, as well as fluorene or spirobifluorene.

In the context of the present invention, an aliphatic hydrocarbon radical or an alkyl group or an alkenyl or alkynyl group which may contain 1 to 20 C atoms and in which individual H atoms or CH2 groups may be substituted by the above-mentioned 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, pentinyl, hexynyl, heptynyl or octynyl. An alkoxy group with 1 to 40 carbon 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, cyclo-octyloxy, 2-ethylhexyloxy, pentafluoroethoxy and 2,2,2-trifluoroethoxy. A thioalkyl group with 1 to 40 C atoms includes in particular methylthio, ethylthio, n-propylthio, i-propylthio, n-butylthio,

1-Butylthio, s-Butylthio, t-Butylthio, n-Pentylthio, s-Pentylthio, n-Hexylthio, Cyclohexylthio, n-Heptylthio, Cycloheptylthio, n-Octylthio, Cyclooctylthio,

2-Ethylhexylthio, trifluoromethylthio, pentafluoroethylthio, 2,2,2-trifluoroethylthio, ethenylthio, propenylthio, butenylthio, pentenylthio, cyclopentenylthio, hexenylthio, cyclohexenylthio, heptenylthio, cycloheptenylthio, octenylthio, cyclooctenylthio, ethynylthio, propynylthio, butynylthio, pentynylthio, hexynylthio, heptynylthio, or octynylthio. In general, alkyl, 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 above-mentioned groups; Furthermore, one or more H atoms can be replaced by D, F, Cl, Br, I, CN or NO2, preferably F, Cl or CN, more preferably F or CN, particularly preferably CN. An aromatic or heteroaromatic ring system with 5 - 60 or 5 to 40 aromatic ring atoms, which may also be substituted with the above-mentioned radicals and which may be linked to the aromatic or heteroaromatic ring via any position, is understood to mean, in particular, groups 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, iso- benzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, pyridine, quinoline, iso-quinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenothiazine, Phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthimidazole, phenanthrimidazole, pyridimidazole, pyrazine-imidazole, quinoxalinimidazole, oxazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, 1,2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, Hexaazatriphenylene, benzopyridazine, pyrimidine, benzopyrimidine, Quinoxaline, 1,5-diazaanthracene, 2,7-diazapyrene, 2,3-diazapyrene, 1,6-diazapyrene, 1,8-diazapyrene, 4,5-diazapyrene, 4,5,9, 10-tetra-azaperylene, 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.

For the purposes of this description, the phrase "two or more residues can form a ring" is understood to mean, among other things, that the two residues are linked by a chemical bond with the formal elimination of two hydrogen atoms. This is illustrated by the following scheme.

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 bonded, forming a ring. This is illustrated by the following scheme:

Preferably, it can be provided that the group Ar is selected, identically or differently on each occurrence, from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthalene, indole, benzofuran, benzothiophene, carbazole, benzimidazolobenzimidazole, dibenzofuran, dibenzothiophene, indenocarbazole, indolocarbazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, isoquinoline, quinazoline, quinoxaline, phenanthrene or triphenylene, which may each be substituted by one or more radicals R other than H, preferably phenyl, biphenyl, fluorene, dibenzofuran, triphenylene, indolocarbazole.

Furthermore, it can preferably be provided that the group Ar is selected, identically or differently at each occurrence, from structures of

Formulas (Ar'-1 ) to (Ar'-29),

where the symbols used are:

Y ¹ is, identically or differently at each occurrence, O, S, NR, BR, Si(R)2, C(R)2, C=C(R)2 or an ortho-linked phenylene group which is one or more radicals R other than H can be substituted, preferably O or NR, particularly preferably NR; k is independently 0 or 1 at each occurrence; i is independently 0, 1 or 2 at each occurrence; j is independently 0, 1, 2 or 3, preferably 0, 1 or 2 at each occurrence; h is independently 0, 1, 2, 3 or 4, preferably 0, 1 or 2 at each occurrence; g is independently 0, 1, 2, 3, 4 or 5, preferably 0, 1 or 2 at each occurrence;

R has the meaning given above, in particular for formula (I), and the dashed bond marks the attachment position.

Structures of the formulae (Ar-1) to (Ar-5), (Ar-7) to (Ar-13), (Ar-18) to (Ar-22), (Ar-24), (Ar-25), (Ar-27), (Ar-28) and (Ar-29) are preferred, structures of the formulae (Ar-1), (Ar-2), (Ar-4), (Ar-5), (Ar-7) to (Ar-9), (Ar-12), (Ar-13), (Ar-19), (Ar-20), (Ar-21) and (Ar-22) are particularly preferred and structures of the formulae (Ar-1), (Ar-2), (Ar-7) to (Ar-9), (Ar-12), (Ar-13) and (Ar-20) are very particularly preferred.

In a preferred embodiment, the compounds according to the invention preferably correspond to at least one of the following formulas (I-1) to (I-7),

where the symbols z, R ^a and R ^b have the meanings given above, in particular for formula (I), and the following applies to the other symbols:

Y is, identically or differently at each occurrence, a single bond, O, S, NR, BR, Si(R) ₂ , C(R) ₂ , (R) ₂ C=C(R) ₂ , P(R), P(=O)R, C=C(R) ₂ or an ortho-linked phenylene group which may be substituted by one or more radicals R other than H, preferably a single bond, O or NR, particularly preferably a single bond or NR;

Y ^a is, identically or differently at each occurrence, O, S, NR, BR, preferably S, O or NR, particularly preferably S or O;

X is, identically or differently at each occurrence, CR or N, preferably CR, where preferably at most two radicals X per ring are N, where R has the meaning given above, in particular for formula (I).

Compounds of the formulas (I-1), (I-5), (I-6) and (I-7) are preferred.

Preferably, in particular in compounds of the formulas (I-1) to (I-7), it can be provided that at most two groups X per ring stand for N, preferably all X stand for CR, preferably at least one, particularly preferably at least two of the groups X per ring are selected from C-H and C-D.

Furthermore, it can be particularly preferred, in particular in compounds of the formulas (I-1) to (I-7), that not more than four, preferably not more than two groups X stand for N, particularly preferably all groups X stand for CR, wherein preferably at most 4, particularly preferably at most 3 and especially preferably at most 2 of the groups CR, which X stands for, are not equal to the group CH or CD.

In a further preferred embodiment, it can be provided that the compound corresponds to at least one of the following formulas (11-1) to (11-16),

where the symbols z, R, R ^a and R ^b have the meanings given above, in particular for formula (I), and the following applies to the other symbols:

Y is, identically or differently at each occurrence, a single bond, O, S, NR, BR, Si(R) ₂ , C(R) ₂ , (R) ₂ C=C(R) ₂ , P(R), P(=O)R, C=C(R) ₂ or an ortho-linked phenylene group which may be substituted by one or more radicals R other than H, preferably a single bond, O or NR, particularly preferably NR; i is, independently at each occurrence, 0, 1 or 2; j is, independently at each occurrence, 0, 1, 2 or 3, preferably 0, 1 or 2; h is, independently at each occurrence, 0, 1, 2, 3 or 4, preferably 0, 1 or 2; and g is, independently at each occurrence, 0, 1, 2, 3, 4 or 5, preferably 0, 1 or 2.

Compounds of the formulas (II-1), (II-4), (II-6) and (II-15) are preferred.

Preferably, in particular for compounds of formulas (II-1) to (II-7), it can be provided that the sum of the indices j, h and g is at most 6, preferably at most 4, and particularly preferably at most 2. In a further preferred embodiment, it can be provided that the compound corresponds to the following formula (III-1) or (III-2), where the symbols R and R ^a have the meanings given above, in particular for formula (I), and the following applies to the other symbols:

Y ² is, identically or differently at each occurrence, B(R ¹ ), C(R ¹ ) 2, Si(R ¹ ) 2, C=O, C=NR ¹ , C=C(R ¹ ) ₂ , O, S, S=O, SO ₂ , N(R ¹ ), P(R ¹ ) and P(=O)R ¹ , preferably B(R ¹ ), C=O or P(=O)R ¹ , particularly preferably B(R ¹ );

Y ³ is, identically or differently at each occurrence, B(R ¹ ), C(R ¹ ) 2, Si(R ¹ ) 2, C=O, C=NR ¹ , C=C(R ¹ ) ₂ , O, S, S=O, SO2, N(R ¹ ), P(R ¹ ) and P(=O)R ¹ , preferably O, N(R ¹ ) or P(R ¹ ), particularly preferably N(R ¹ ); and j is, independently at each occurrence, 0, 1, 2 or 3, preferably 0, 1 or 2.

Furthermore, in particular for compounds of formula (III-1) or (III-2), the sum of the indices j and h may be at most 8, preferably at most 6, particularly preferably at most 5 and particularly preferably at most 3.

Furthermore, it should be noted that some of the compounds presented above and below may have multiple isomeric, enantiomeric, diastereomeric, or tautomeric forms. These compounds are comprehensively represented by the structures presented, so that The form shown represents all such isomeric, enantiomeric, diastereomeric or tautomeric forms, unless something different is explicitly stated.

In a preferred development of the present invention, it can be provided that at least two, preferably adjacent, radicals R form a condensed ring with the further groups to which the two radicals R bind, wherein the two radicals R form at least one structure of the formulas (RA-1) to (RA-12)

where R ¹ has the meaning set out above, the dashed bonds represent the attachment points to the atoms of the groups to which the two radicals R are bound, and the other symbols have the following meaning:

Y ⁴ is, identically or differently at each occurrence, C(R ¹ ) 2, (R ¹ ) ₂ CC(R ¹ ) 2, (R ¹ )C=C(R ¹ ), NR ¹ , NAr', O or S, preferably C(R ¹ ) ₂ , (R ¹ ) ₂ CC(R ¹ ) 2, (R ¹ )C=C(R ¹ ), O or S;

R ^c is, identically or differently on each occurrence, F, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms or an alkenyl or alkynyl group having 2 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 C atoms, where the alkyl, alkoxy, thioalkoxy, alkenyl or alkynyl group may each be substituted by one or more radicals R ² other than H, where one or more non-adjacent CH 2 groups are substituted by R ² C=CR ² , C=C, Si(R ² ) ₂ , C=O, C=S, C=Se, C=NR ² , -C(=O)O-, -C(=O)NR ² -, NR ² , P(=O)(R ² ), -O-, -S-, SO or SO2, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, each of which may be substituted by one or more radicals ^R2 other than H, or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals ^R2 other than H; two radicals ^Rc can also form a ring system with one another, or a radical ^Rc can form a ring system with a radical ^R1 or with another group, where ^R2 has the meaning given in claim 1; s is 0, 1, 2, 3, 4, 5, 6, 7 or 8, preferably 0, 1, 2, 3 or 4, particularly preferably 0, 1 or 2; t is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10, preferably 0, 1, 2, 3 or 4, particularly preferably 0, 1 or 2; v is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, preferably 0, 1, 2, 3 or 4, particularly preferably 0, 1 or 2.

Structures of the formulas RA-1, RA-3, RA-4 and RA-5 are preferred and structures of the formulas RA-4 and RA-5 are particularly preferred.

In a preferred embodiment of the invention, at least two, preferably adjacent, radicals R form a condensed ring with the further groups to which the two radicals R bind, wherein the two radicals R form the structures of the formulas (RA-1a) to (RA-4f)

where the dashed bonds represent the attachment points to the atoms of the groups to which the two radicals R bind, the index m is 0, 1, 2, 3 or 4, preferably 0, 1 or 2, and the symbols R ¹ , R ² , R ^c and the indices s and t have the meaning set out above, in particular for formula (I) and/or formulas (RA-1) to (RA-12).

Structures of the formula RA-4f are preferred.

Furthermore, it can be provided that the at least two radicals R which form structures of the formulas (RA-1) to (RA-12) and/or (RA-1a) to (RA-4f) and form a condensed ring, represent radicals R from adjacent groups X or represent radicals R which are each bonded to adjacent C atoms, wherein these C atoms are preferably connected via a bond.

In a further preferred embodiment, preferably at least two, preferably adjacent, radicals R form a condensed ring with the further groups to which the two radicals R bind, wherein the two radicals R form structures of the formula (RB) where R ¹ has the meaning given above, in particular for formula (I), the dashed bonds represent the attachment points via which the two radicals R bind, the index m is 0, 1, 2, 3 or 4, preferably 0, 1 or 2, and Y ⁵ is C(R ¹ ) 2, NR ¹ , NAr', BR ¹ , BAr', O or S, preferably C(R ¹ ) 2, NAr' or O, particularly preferably C(R ¹ ) 2 or O, where Ar' has the meaning given above, in particular for formula (I).

Furthermore, it can be provided that the at least two radicals R which form structures of the formula (RB) and form a condensed ring represent radicals R from adjacent groups X or represent radicals R which are each bonded to adjacent C atoms, wherein these C atoms are preferably connected via a bond.

Particularly preferably, the compound corresponds to at least one structure of the following formulas (IV-1) to (IV-6), wherein the compounds have at least one condensed ring,

where the symbols z, R and R ^a have the meanings given above, in particular for formula (I), the symbol o stands for the condensation sites of the at least one condensed ring and the following applies to the further indices used: i is, independently at each occurrence, 0, 1 or 2, preferably 0 or 1; h is, independently at each occurrence, 0, 1, 2, 3 or 4, preferably 0, 1 or 2; and g is, independently at each occurrence, 0, 1, 2, 3, 4 or 5, preferably 0, 1 or 2.

Furthermore, in particular for compounds of the formulas (IV-1) to (IV-6), it can be provided that the condensed ring is formed by structures of the formulas (RA-1) to (RA-12), (RA-1a) to (RA-4f) and/or (RB), as previously shown, preferably by structures of the formulas (RB). Furthermore, for compounds of the formulas (IV-1) to (IV-6) it can be provided that the sum of the indices i, h, g and z is at most 10, preferably at most 8, particularly preferably at most 6 and particularly preferably at most 4.

Preferably, the compounds may have at least two condensed rings, wherein at least one condensed ring is formed by structures of the formulas (RA-1) to (RA-12) and/or (RA-1 a) to (RA-4f) and a further ring is formed by structures of the formulas (RA-1) to (RA-12), (RA-1 a) to (RA-4f) or (RB).

Furthermore, it can be provided that the substituents R and R ¹ according to the above formulas do not form a fused aromatic or heteroaromatic ring system with the ring atoms of the ring system to which the substituents R and R ¹ are bonded. This includes the formation of a fused aromatic or heteroaromatic ring system with possible substituents R ¹ and R ² , which may be bonded to the substituents R and R ¹ .

The radicals R ^a or R ^b preferably do not form a ring system with other groups. If substituents R ^a form a ring system with each other, this ring is preferably formed by exactly two radicals R ^a bonded to a C atom.

If the compound according to the invention is substituted by aromatic or heteroaromatic groups R, R ¹ or R ² , it is preferred in one embodiment if these do not contain any aryl or heteroaryl groups with more than two directly fused aromatic six-membered rings. Particularly preferably, the substituents do not contain any aryl or heteroaryl groups with directly fused six-membered rings. This preference is due to the low triplet energy of such structures. Condensed aryl groups with more than two directly fused aromatic six-membered rings, which are nevertheless also suitable according to the invention, are phenanthrene and triphenylene, as these also have a high triplet level.

Furthermore, it can be provided that the radical R, R ¹ or R ² does not comprise an aromatic or heteroaromatic ring system which has three linearly condensed aromatic 6-rings, wherein preferably none of the radicals R comprises an aromatic or heteroaromatic ring system which has three linearly condensed aromatic 6-rings.

Furthermore, it can be provided that the substituents R and R ¹ according to the above formulas do not form a fused aromatic or heteroaromatic ring system with the ring atoms of the ring system, preferably not a fused ring system. This includes the formation of a fused ring system with possible substituents R ¹ and R ² , which can be bonded to the radicals R, R ¹ .

When two radicals, which can in particular be selected from R, R ¹ and/or R ² , form a ring system with one another, this can be mono- or polycyclic, aliphatic, heteroaliphatic, aromatic or heteroaromatic. The radicals forming a ring system with one another can be adjacent, i.e. these radicals are bonded to the same carbon atom or to carbon atoms that are directly bonded to one another, or they can be further apart. Furthermore, the ring systems provided with the substituents R, R ¹ and/or R ² can also be linked to one another via a bond, so that a ring closure can thereby be effected.

Furthermore, it can be provided that at least one radical R is selected, identically or differently on each occurrence, from the group consisting of an aromatic or heteroaromatic ring system selected from the groups of the following formulae Ar-1 to Ar-76, and/or the group Ar' is selected, identically or differently on each occurrence, from the groups of the following formulae Ar-1 to Ar-76,

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

Ar ¹ is, at each occurrence, identically or differently, a bivalent aromatic or heteroaromatic ring system having 6 to 18 aromatic ring atoms, each of which may be substituted by one or more radicals R ¹ ;

A is, identically or differently at each occurrence, C(R ¹ ) 2, NR ¹ , O or S; p is 0 or 1, where p = 0 means that the group Ar ¹ is not present and that the corresponding aromatic or heteroaromatic group is directly bonded to the corresponding residue; q is 0 or 1 , where q = 0 means that no group A is bonded to this position and residues R ¹ are bonded to the corresponding carbon atoms instead.

The structures of formulas (Ar-1) to (Ar-76) presented above represent preferred embodiments of the radicals Ar, as defined, for example, for structures of formula (I), in which case the substituents R ¹ in formulas (Ar-1) to (Ar-76) are to be replaced by R, where R has the meaning given above, in particular for formula (I).

Structures of the formulas (Ar-1), (Ar-2), (Ar-3), (Ar-12), (Ar-13), (Ar-14), (Ar-15), (Ar-16), (Ar-40), (Ar-41), (Ar-42), (Ar-43), (Ar-44), (Ar-45), (Ar-46), (Ar-69), (Ar-70), (Ar-76) are preferred and structures of the formulas (Ar-1), (Ar-2), (Ar-3), (Ar-12), (Ar-13), (Ar-14), (Ar-15), (Ar-16) are particularly preferred.

If the above-mentioned groups for structures of the formulas (Ar-1) to (Ar-76) have multiple A groups, all combinations from the definition of A are possible. Preferred embodiments are then those in which one A group represents NR ¹ and the other A group represents C(R ¹ ) 2, or in which both A groups represent NR ¹ , or in which both A groups represent 0.

When A stands for NR ¹ , the substituent R ¹ which is bonded to the nitrogen atom preferably stands for 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, stands for an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, in particular having 6 to 18 aromatic ring atoms, which does not have any fused aryl groups and which does not have any fused heteroaryl groups in which two or more aromatic or heteroaromatic 6-ring groups are directly fused to one another, and which may in each case also be substituted by one or more radicals R ² . Phenyl, biphenyl, terphenyl, and quaterphenyl are preferred. Also preferred are triazine, pyrimidine, and quinazoline, as listed above for Ar-47 to Ar-50, Ar-57, and Ar-58, where these structures may be substituted by one or more R ² radicals instead of R ¹ .

When A stands for C(R ¹ ) 2 , the substituents R ¹ bonded to this carbon atom, preferably identical or different on each occurrence, 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 . Very particularly preferably, R ¹ stands for 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 a preferred embodiment of the invention, R is the same or different on each occurrence and is selected from the group consisting of H, D, F, CN, NO2, Si( ^R1 )3, N( ^OR1 )2, B( ^OR1 )2, 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 may in each case be substituted by one or more radicals ^R1 other than H, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, preferably having 5 to 40 aromatic ring atoms, which may in each case be substituted by one or more radicals ^R1 other than H.

In a further preferred embodiment of the invention, radical R is selected, identically or differently on each occurrence, from the group consisting of H, D, F, 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 may in each case be substituted by one or more radicals R ¹ , or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, preferably having 5 to 40 aromatic ring atoms, which may in each case be substituted by one or more radicals R ¹ other than H. Furthermore, it can be provided that at least one radical R, preferably a substituent R, is selected, identically or differently on each occurrence, from the group consisting of H, D, an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, which may be substituted by one or more radicals R ¹ other than H, or a group N(Ar')2, particularly preferably at least one substituent R is selected, identically or differently on each occurrence, from the group consisting of an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, which may be substituted by one or more radicals R ¹ other than H, or a group N(Ar')2.

Especially preferably, at least one substituent R is selected, identically or differently on each occurrence, from the group consisting of an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, which may be substituted by one or more radicals R ¹ other than H. In a further preferred embodiment of the invention, the substituents R either form a ring according to the structures of the formulas (RA-1) to (RA-12), (RA-1a) to (RA-4f) or (RB) or the radical R is selected, identically or differently on each occurrence, from the group consisting of H, D, an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, which may be substituted by one or more radicals R ¹ , or a group N(Ar')2. Particularly preferably, the radical R is preferably the substituent R, identically or differently on each occurrence, selected from the group consisting of H, D or an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, preferably having 6 to 18 aromatic ring atoms, particularly preferably having 6 to 13 aromatic ring atoms, which may each be substituted by one or more radicals R ¹ .

Furthermore, it can be provided that at least one radical R represents an aromatic or heteroaromatic ring system having 5 to 13 aromatic ring atoms, which can be substituted by one or more radicals R ¹ . Preferably, it can be provided that at least one radical, preferably a substituent R, is selected, identically or differently on each occurrence, from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthalene, indole, benzofuran, benzothiophene, carbazole, benzimidazolobenzimidazole, dibenzofuran, dibenzothiophene, indenocarbazole, indolocarbazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, isoquinoline, quinazoline, quinoxaline, phenanthrene or triphenylene, which may each be substituted by one or more radicals R ¹ other than H.

Here, the term "substituent" means, in particular, that R is not H. Furthermore, the R substituents may be the same or different if two or more substituents are present that are selected from the aromatic or heteroaromatic groups mentioned. In this context, it should also be noted that, both above and below, in the structures, the maximum number of substituents is defined by indices that are smaller than the number of bonding sites on one or more C atoms. In this case, H or D atoms are bonded to the bonding sites, so that the respective group has a smaller number of substituents than would be theoretically possible.

Furthermore, it can preferably be provided that the group R ^a stands for H, D, methyl, ethyl, propyl, where these groups can be deuterated, where the group R ^a preferably stands for H or D.

Preferably, the group R ^b may be methyl, ethyl, propyl, butyl or pentyl, preferably methyl, ethyl, isopropyl, tert-butyl or neo-pentyl, where these groups may be deuterated.

In a preferred embodiment of the invention, R ^c is the same or different on each occurrence and is selected from the group consisting of 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 may be substituted in each case by one or more radicals R ² , or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, preferably having 5 to 40 aromatic ring atoms, which may be substituted in each case by one or more radicals R ² .

In a further preferred embodiment of the invention, R ^c is the same or different on each occurrence and is selected from the group consisting of a straight-chain alkyl group having 1 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms, where the alkyl group may be substituted in each case by one or more radicals R ² , an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, which may be substituted by one or more radicals R ² . Particularly preferably, R ^c is selected, identically or differently on each occurrence, from the group consisting of a straight-chain alkyl group having 1 to 5 C atoms or a branched or cyclic alkyl group having 3 to 5 C atoms, where the alkyl group may in each case be substituted by one or more radicals R ² or an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, preferably having 6 to 18 aromatic ring atoms, particularly preferably having 6 to 13 aromatic ring atoms, which may in each case be substituted by one or more radicals R ² .

In a preferred embodiment of the invention, R ^c is selected, identically or differently at each occurrence, from the group consisting of a straight-chain alkyl group having 1 to 6 C atoms or a cyclic alkyl group having 3 to 6 C atoms, where the alkyl group may in each case be substituted by one or more radicals R ² , or an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, which may in each case be substituted by one or more radicals R ² ; two radicals R ^c may also form a ring system with one another. Particularly preferably, R ^c is selected, identically or differently at each occurrence, from the group consisting of a straight-chain alkyl group 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 which may in each case be substituted by one or more radicals R ² , but is preferably unsubstituted, or an aromatic ring system having 6 to 12 aromatic ring atoms, in particular having 6 aromatic ring atoms, which may in each case be substituted by one or more, preferably non-aromatic radicals R ² , but is preferably unsubstituted; two radicals R ^c can here form a ring system with one another. R ^c is very particularly preferably selected, identically or differently, on each occurrence from the group consisting of a straight-chain alkyl group having 1, 2, 3 or 4 C atoms, or a branched alkyl group having 3 to 6 C atoms. R ^c very particularly preferably represents a methyl group or a phenyl group, where two phenyl groups together can form a ring system, where a methyl group is preferred over a phenyl group.

Preferred aromatic or heteroaromatic ring systems represented by substituents R, R ¹ , R ^c or Ar 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 may be linked via the 1-, 2-, 3- or 4-position, spirobifluorene, which may be linked via the 1-, 2-, 3- or 4-position, naphthalene, in particular 1- or -linked naphthalene, indole, benzofuran, benzothiophene, carbazole, which may be linked via the 1-, 2-, 3- or 4-position, dibenzofuran, which may be linked via the 1-, 2-, 3- or 4-position, Dibenzothiophene, which may be linked via the 1-, 2-, 3- or 4-position, indenocarbazole, indolocarbazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, isoquinoline, quinazoline, quinoxaline, anthracene, pyrene, perylene, chrysene, phenanthrene or triphenylene, each of which may be substituted by one or more radicals R, R ¹ or R ^2, respectively. Particularly preferred are the structures Ar-1 to Ar-76 listed above, with structures of the formulas (Ar-1), (Ar-2), (Ar-3), (Ar-12), (Ar-13), (Ar-14), (Ar-15), (Ar-16), (Ar-69), (Ar-70), (Ar-76) being preferred and structures of the formulas (Ar-1), (Ar-2), (Ar-3), (Ar-12), (Ar-13), (Ar-14), (Ar-15), (Ar-16) being particularly preferred. With regard to the structures Ar-1 to Ar-76, it should be noted that these are represented with a substituent R ¹ In the case of the ring systems Ar, these substituents R ¹ are to be replaced by R and in the case of R ¹ or R ^c , these substituents R ¹ are to be replaced by R ² .

Other suitable R groups are groups of the formula -Ar ⁴ -N(Ar ² )(Ar ³ ), where Ar ² , Ar ³ and Ar ^{4 ,} identical or different on each occurrence, represent an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, each of which may be substituted by one or more radicals R ¹ . The total number of aromatic ring atoms of Ar ² , Ar ³ and Ar ⁴ is a maximum of 60 and preferably a maximum of 40.

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

Preferably, Ar ⁴ is an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, preferably having 6 to 12 aromatic ring atoms, each of which may be substituted by one or more radicals R ¹ . Particularly preferably, Ar ⁴ is 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. Most preferably, Ar ⁴ is an unsubstituted phenylene group.

Preferably, Ar ² and Ar ³ , identical or different on each occurrence, 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 , identical or different on each occurrence, 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-spirobifluorenyl, 1- or 2-naphthyl, indole, benzofuran, benzothiophene, 1-, 2-, 3- or 4-carbazole, 1-, 2-, 3- or 4-dibenzofuran, 1-, 2-, 3- or 4-di-benzothiophene, indenocarbazole, indolocarbazole, 2-, 3- or 4-pyridine, 2-,

4- or 5-pyrimidine, pyrazine, pyridazine, triazine, phenanthrene or triphenylene, which may each be substituted by one or more radicals R ^1. Very particular preference is given to Ar ² and Ar ³ , identical or different on each occurrence, being selected from the group 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.

In a further preferred embodiment of the invention, R ¹ 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 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms, where the alkyl group may in each case be substituted by one or more radicals R ² , or an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, which may in each case be substituted by one or more radicals R ² . In a particularly preferred embodiment of the invention, R ¹ is selected, identically or differently on each occurrence, 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 may be substituted by one or more radicals R ² , but is preferably unsubstituted, or an aromatic or heteroaromatic ring system having 6 to 13 aromatic ring atoms, each of which may be substituted by one or more radicals R ² , but is preferably unsubstituted.

In a further preferred embodiment of the invention, R ² is, identically or differently on each occurrence, H, 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. In compounds according to the invention that are processed by vacuum evaporation, the alkyl groups preferably have no more than five carbon atoms, particularly preferably no more than 4 carbon atoms, and most preferably no more than 1 carbon atom. Also suitable for compounds that are processed from solution are compounds that are substituted by alkyl groups, particularly branched alkyl groups, with up to 10 carbon atoms, or that are substituted by oligoarylene groups, for example ortho-, meta-, para-, or branched terphenyl or quaterphenyl groups.

When the compounds of formula (I) or the preferred embodiments are used as matrix material for a phosphorescent emitter or in a layer 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. Exceptions to this are phenanthrene and triphenylene, which may be preferred due to their high triplet energy despite the presence of condensed aromatic six-membered rings.

Preferably, in one embodiment, the compound may not comprise an aromatic or heteroaromatic ring system having three aromatic 6 rings fused to one another.

In a further embodiment, the compound may comprise an aromatic or heteroaromatic ring system comprising three fused aromatic rings. This applies in particular to use in combination with or as a fluorescent emitter.

The present compounds preferably serve as components in electronic devices, particularly preferably as functional ones, and can therefore preferably contain functional groups. These include, among others, those described above and below. Hole transport groups, electron transport groups and emitting groups.

Preferably, it can be provided that the connection comprises at least one hole transport group.

Hole-transport groups are widely known in the scientific community. These include, in particular, di- and triarylamine groups, carbazole groups, and groups with similar properties. Preferred groups include, for example, residues Ar-76, as defined above.

Preferably, the compound may comprise at least one electron transport group.

Electron-transport groups are widely known in the art and enhance the ability of compounds to transport and/or conduct electrons. These include, in particular, nitrogen-containing heteroaryl groups with 5 to 12 ring atoms, particularly preferably with 6 to 12 ring atoms, which are generally electron-poor heteroaryl groups.

Preferably, it can be provided that the compound comprises at least one electron transport group which is selected from pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinazoline, quinoxaline, quinoline, isoquinoline, imidazole and/or benzimidazole groups, preferably pyrimidine, pyrazine, triazine, quinazoline, quinoxaline and/or benzimidazole groups, particularly preferably a pyrimidine, triazine, quinazoline and/or quinoxaline group, particularly preferably pyrimidine and/or triazine groups, very particularly preferably triazine groups, which can be substituted by one or more radicals R, R ¹ or R ² , depending on the position at which the group is formed or bonded.

In one embodiment, it can be provided that the compound does not contain a carbazole group, preferably a carbazole group and/or no substituents of the formula N(Ar')2, N(R ¹ )2 and particularly preferably no hole transport group.

Compounds having one or more electron transport groups that do not comprise a hole transport group are particularly suitable as electron injection material, electron transport material or hole blocking material that are used in a corresponding layer, wherein this layer generally does not contain an emitting compound.

In a further embodiment, it can be provided that the compound comprises at least one hole transport group, preferably a carbazole group and/or a substituent of the formula N(Ar’)2, and particularly preferably a carbazole group.

Furthermore, it can be provided that the compound does not comprise a triazine group, preferably no pyrimidine and/or triazine group and particularly preferably no electron transport group.

Compounds with one or more hole transport groups that do not comprise an electron transport group are particularly suitable as hole injection material, hole transport material or electron blocking material that are used in a corresponding layer, wherein this layer generally does not contain an emitting compound.

In a further embodiment, it can be provided that the compound comprises at least one electron transport group and at least one hole transport group, preferably at least one carbazole group and/or at least one substituent of the formula N(Ar')2, and particularly preferably a carbazole group.

Compounds with one or more electron transport groups that include at least one hole transport group are particularly suitable as host materials that are used in combination with an emitting compound. Furthermore, it can preferably be provided that the compound comprises at least one emitting group.

Emitting groups are also widely known and lead to, among others, fluorescent emitters, phosphorescent emitters, emitters exhibiting TADF.

Groups that lead to fluorescent emitters are generally known, and these groups often contain fused aromatic rings, such as fluorene, anthracene, and/or pyrene groups, which may be substituted by groups R ¹ or R ² . Phosphorescent emitters are widely known in the art, with particular use being made of metal complexes, which are described later herein. Emitters that exhibit TADF are also well described. Preferred emitters include, among others, DABNA types and compounds with similar properties, including, for example, the compounds shown in formulas (III-1) or (III-2), wherein these compounds preferably contain at least one B and at least one N atom.

In a preferred embodiment, the compounds according to the invention have a high degree of deuteration. The degree of deuteration can preferably be at least 50%, preferably at least 80%, especially preferably at least 90%, and most preferably at least 95%. The degree of deuteration is determined from the numerical ratio of deuterium to the sum of deuterium and ^1H hydrogen (D/(D+H)*100). The compounds are especially preferably fully deuterated.

Preferably, it can be provided that the compound has a molecular weight of less than or equal to 5000 g/mol, preferably less than or equal to 4000 g/mol, particularly preferably less than or equal to 3000 g/mol, especially preferably less than or equal to 2000 g/mol, more especially preferably less than or equal to 1200 g/mol and very particularly preferably less than or equal to 900 g/mol. Furthermore, preferred compounds according to the invention are characterized by their sublimability. These compounds generally have a molecular weight of less than approximately 1200 g/mol.

Preferably, the compound may not comprise any alkoxy, thioalkoxy or hydroxy groups.

Furthermore, it can be provided that the compound according to formula (I) or a preferred embodiment of these structures/compounds is not in direct contact with a metal atom, preferably does not represent a ligand for a metal complex.

In a further preferred embodiment, it can be provided that the compound according to formula (I) or a preferred embodiment of these structures/compounds is coordinated to a transition metal, preferably represents a ligand for a metal complex.

A further subject of the present invention is therefore a metal complex containing one or more compounds of the present invention, wherein the metal complexes correspond to the general formula (1):

M(L) _n (L')m Formula (1 ) where the symbols and indices used are:

M is a transition metal, preferably Cu, Mo, W, Re, Ru, Os, Rh, Ir, Pd, Pt, Ag, Au or Eu, particularly preferably Pt, Ir,

L is a bidental ligand;

L' is, identically or differently on each occurrence, a ligand; n is 1, 2 or 3, preferably 2, particularly preferably 3; m is 0, 1, 2, 3 or 4, preferably 0, 1 or 2, particularly preferably 0; several ligands L can also be linked to one another or L to L' via a single bond or a bivalent or trivalent bridge and thus form a tridentate, tetradentate, pentadentate or hexadentate ligand system; wherein at least one of the ligands L, L' represents a structure according to formula (I) or a preferred embodiment of these structures/compounds.

Furthermore, it can be provided that the metal complexes of the general formula (1 ) contain a partial structure M(L) _n of the formula (2) where M has the meaning given in claim 37 and the symbols and indices used are:

CyC is an aryl or heteroaryl group having 5 to 18 aromatic ring atoms or a fluorene or azafluorene group, each of which is coordinated to Ir via a carbon atom and which may be substituted by one or more radicals R and which is linked to CyD via a covalent bond, where R has the meaning given above, in particular for formula (I);

CyD is a heteroaryl group having 5 to 18 aromatic ring atoms, which is coordinated to Ir via a neutral nitrogen atom or via a carbene carbon atom and which may be substituted by one or more radicals R and which is linked to CyC via a covalent bond, where R has the meaning given above, in particular for formula (I); n is 1, 2 or 3, preferably 2, particularly preferably 3; several ligands L can also be linked to one another via a single bond or a bivalent or trivalent bridge and thus form a tridentate, tetradentate, pentadentate or hexadentate ligand system; A substituent can also additionally coordinate to M; wherein at least one of the group CyC or CyD represents a structure according to formula (I) or a preferred embodiment of these structures/compounds.

The disclosure of patent application WO 2018/001990A1 (with application number PCT/EP2017/065763) relating to this application, in particular the disclosure relating to the metal complexes described by formulas (1) and (2), is incorporated by reference into the present application for disclosure purposes. This application is limited to Ir complexes, and the present application encompasses further complexes and is expanded accordingly. In particular, the CyC and CyD groups are exemplified in this application.

The above-mentioned preferred embodiments can be combined with each other 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 preferred compounds according to the embodiments listed above are the compounds listed in the following table.

The basic structure of the compounds of the invention can be prepared according to the methods outlined in the following schemes. The individual synthesis steps, such as coupling reactions leading to C-C bond formations and/or C-N bond formations, are known in principle to those skilled in the art. These include, among others, reactions according to BUCHWALD, SUZUKI, YAMAMOTO, STILLE, HECK, NEGISHI, SONOGASHIRA, and HIYAMA.

Further information on the synthesis of the compounds according to the invention can be found in the synthesis examples.

The compounds according to the invention can be prepared starting from the literature-known octahydro-3,5,1,7-[1,2,3,4]butanetetraylnaphthalene-2(1H)-one [30545-23-4] (1) by methods known from the literature. According to Scheme 1, (1) is first reacted with a metal organyl, e.g. an organolithium or a Grignard compound, to give the alcohol (2), see e.g. J. Mikolajv et al., Synthetic Communications (1983), 13(1), 53-62. This alcohol is then reacted in the presence of a Nucleophile Ar-RG is converted in an acid-catalyzed Friedel-Krafts reaction b) to the reactive intermediate (3), see, for example, CN 115490601. This is then reacted with suitable aryl-Z-heteroaryl halides or amines to give the inventive materials E by means of functionalization reactions c) familiar to the person skilled in the art, such as CC or CN couplings of the Suzuki, Negishi, Yamamoto-Grignard-Cross, Buchwald-Hartwig, Ullmann, etc. types, see Scheme 1.

The reactive spirofluorene intermediates (5) are obtainable from the ketone (1) and 2-bromo-(2'/374')-RG-biphenylene by monolithation thereof, addition of the 2-lithio-(2'/374')-RG-biphenyl and acid-catalyzed intramolecular dehydrating cyclization of the intermediately formed alcohol, d), see e.g. US 2022/0220049, page 80 "Intermediates I-A-1 and I-A-2", and can be further converted to the compounds E (4) according to the invention by means of step c) as described above, see Scheme 2.

Scheme 2: The reactive spiro intermediates (6) are accessible according to Scheme 3, whereby the reaction course is similar to that described in Scheme 2, whereby 2-bromo-aryl-(2'/374')-chloro-aryl-alkanes, -amines, -ethers or -thioethers are used instead of the 2-bromo-(2'/374')-RG-biphenyls, see.

Scheme 3.

The meaning of the symbols used in the scheme presented above essentially corresponds to that defined for formula (I), although for reasons of clarity, numbering and a complete representation of all symbols have been omitted and preferred radicals for the group Ar are shown.

A further object of the present invention is therefore a process for preparing a compound according to the invention, wherein a compound having an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms is synthesized and reacted with a ketone which has a pentacyclic alkyl group in the alpha position.

By these processes, optionally followed by purification, such as recrystallization or sublimation, the compounds according to the invention can be obtained in high purity, preferably more than 99% (determined by ¹ H-NMR and/or HPLC).

The compounds according to the invention can also be mixed with a polymer. It is also possible to incorporate these compounds covalently into a polymer. This is particularly possible with compounds which contain reactive leaving groups, such as bromine, iodine, chlorine, boronic acid or boronic acid esters, or with reactive, polymerizable groups, such as Olefins or oxetanes. These can be used as monomers to produce corresponding oligomers, dendrimers, or polymers. The oligomerization or polymerization preferably takes place via the halogen functionality or the boronic acid functionality, or via the polymerizable group. It is also possible to crosslink the polymers via such groups. The compounds and polymers according to the invention can be used as crosslinked or uncrosslinked layers.

The invention therefore further provides oligomers, polymers or dendrimers comprising one or more of the above-listed structures of the formula (I) and preferred embodiments of this formula or compounds according to the invention, wherein one or more bonds of the compounds according to the invention or of the structures of the formula (I) and preferred embodiments of this formula to the polymer, oligomer or dendrimer are present. Depending on the linkage of the structures of the formula (I) and preferred embodiments of this formula or of the compounds, these therefore form a side chain of the oligomer or polymer or are linked in the main chain. The polymers, oligomers or dendrimers can be conjugated, partially conjugated or non-conjugated. The oligomers or polymers can be linear, branched or dendritic. The same preferences apply to the repeating units of the compounds according to the invention in oligomers, dendrimers and polymers as described above.

Particularly preferred are oligomers which comprise exactly two, exactly three or exactly four compounds according to formula (I).

In a preferred embodiment, it can be provided that the oligomer corresponds to the formula (D-1)

where the group L ¹ represents a connecting group, preferably a bond or an aromatic or heteroaromatic ring system having 5 to 40, preferably 5 to 30 aromatic ring atoms, which may be substituted by one or more radicals R, and the further symbols and indices used have the meanings given above, in particular for formula (I), where the group L ¹ forms a bond to the basic structure instead of a hydrogen atom or a substituent, preferably the group L ¹ binds to the radical Ar or the radical Ar together with the group U and the group L1 forms an aromatic or heteroaromatic ring system having 5 to 60, preferably 10 to 40 aromatic ring atoms, which may be substituted by one or more radicals R other than H.

In a further preferred embodiment of the invention, L ¹ represents a bond or an aromatic or heteroaromatic ring system having 5 to 14 aromatic or heteroaromatic ring atoms, preferably an aromatic ring system having 6 to 12 carbon atoms, which may be substituted by one or more radicals R other than H, but is preferably unsubstituted, where R may have the meaning given above, in particular for formula (I). More preferably, L ¹ represents an aromatic ring system having 6 to 10 aromatic ring atoms or a heteroaromatic ring system having 6 to 13 heteroaromatic ring atoms, each of which may be substituted by one or more radicals R ¹ , but is preferably unsubstituted, where R ¹ may have the meaning given above, in particular for formula (I). Furthermore, the symbol L ¹ shown, inter alia, in formula (D1) is preferably identical or different on each occurrence and represents a bond or an aryl or heteroaryl radical having 5 to 24 ring atoms, preferably 6 to 13 ring atoms, particularly preferably 6 to 10 ring atoms, so that an aromatic or heteroaromatic group of an aromatic or heteroaromatic ring system is bonded directly, ie via an atom of the aromatic or heteroaromatic group, to the respective atom of the further group.

Furthermore, it can be provided that the group L ¹ shown in formula (D1) comprises an aromatic ring system with at most four, preferably at most three, particularly preferably at most two fused aromatic and/or heteroaromatic 6-membered rings, preferably no fused aromatic or heteroaromatic ring system. Accordingly, naphthyl structures are preferred over anthracene structures. Furthermore, fluorenyl, spirobifluorenyl, dibenzofuranyl, and/or dibenzothienyl structures are preferred over naphthyl structures.

Particularly preferred are structures which do not exhibit condensation, such as phenyl, biphenyl, terphenyl and/or quaterphenyl structures.

Examples of suitable aromatic or heteroaromatic ring systems L ¹ are selected from the group consisting of ortho-, meta- or para-phenylene, ortho-, meta- or para-biphenylene, terphenylene, in particular branched terphenylene, quaterphenylene, in particular branched quaterphenylene, fluorenylene, spirobifluorenylene, dibenzofuranylene, dibenzothienylene and carbazolylene, which may each be substituted by one or more radicals R ¹ , but are preferably unsubstituted.

In a preferred embodiment, the oligomer preferably corresponds to one of the following formulas (D-1-1) to (D-1-24), where the symbols z, U, R and ^Ra have the meanings given above, in particular for formula (I), and the following applies to the further indices used: k is independently 0 or 1 at each occurrence; i is independently 0, 1 or 2, preferably 0 or 1 at each occurrence; j is independently 0, 1, 2 or 3, preferably 0 or 1 at each occurrence; h is independently 0, 1, 2, 3 or 4, preferably 0, 1 or 2 at each occurrence; and g is independently 0, 1, 2, 3, 4 or 5, preferably 0, 1 or 2 at each occurrence.

Oligomers of the formulas D-1-4, D-1-5, D-1-13, D-1-15, D-1-17 and D-1-24 are preferred and oligomers of the formulas D-1-4, D-1-5 and D-1-15 are particularly preferred.

To prepare the oligomers or polymers, the monomers according to the invention can be homopolymerized or copolymerized with other monomers. Copolymers are preferred, wherein the units according to formula (I) or the preferred embodiments described above and below are present in amounts of 0.01 to 99.9 mol%, preferably 5 to 90 mol%, particularly preferably 20 to 80 mol%.

Suitable and preferred comonomers which form the polymer backbone are selected from fluorenes (e.g. according to EP 842208 or WO 2000/022026), spirobifluorenes (e.g. according to EP 707020, EP 894107 or WO 2006/061181), para-phenylenes (e.g. according to WO 92/18552), carbazoles (e.g. according to WO 2004/070772 or WO 2004/113468), thiophenes (e.g. according to EP 1028136), dihydrophenanthrenes (e.g. according to WO 2005/014689), cis- and trans-indenofluorenes (e.g. according to WO 2004/041901 or WO 2004/113412), ketones (e.g., according to WO 2005/040302), phenanthrenes (e.g., according to WO 2005/104264 or WO 2007/017066), or even several of these units. The polymers, oligomers, and dendrimers may contain further units, for example, hole-transport units, particularly those based on triarylamines, and/or electron-transport units. Of particular interest are also compounds according to the invention that are characterized by a high glass transition temperature. In this context, compounds according to the invention that have a glass transition temperature of at least 70 °C, more preferably of at least 110 °C, most preferably of at least 125 °C, and especially preferably of at least 150 °C, determined according to DIN 51005 (version 2005-08), are particularly preferred.

For processing the compounds of the invention from the liquid phase, for example by spin coating or printing processes, formulations of the compounds of the invention are required. These formulations can be, for example, solutions, dispersions, or emulsions. It may be preferred 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, a-terpineol, benzothiazole, butylbenzoate, cumene, cyclohexanol, cyclohexanone, Cyclohexylbenzene, decalin, dodecylbenzene, ethyl benzoate, indane, NMP, p-cymene, phenetol, 1,4-diisopropylbenzene, di-benzyl ether, diethylene glycol butyl methyl ether, triethylene glycol butyl methyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, di- ethylene glycol monobutyl ether, tripropylene glycol dimethyl ether, tetra-ethylene glycol dimethyl ether, 2-isopropylnaphthalene, pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene, 1,1-bis(3,4-dimethylphenyl)ethane, 2-methylbiphenyl, 3-methylbiphenyl, 1-methylnaphthalene, 1 -Ethylnaphthalene, ethyl octanoate, diethyl sebacate, octyloctanoate, heptylbenzene, menthyl isovalerate, Cyclohexylhexanoate or mixtures of these solvents.

A further subject of the present invention is therefore a formulation or a composition containing at least one compound according to the invention and at least one further compound. The further compound can, for example, be a solvent, in particular one of the above-mentioned solvents or a mixture of these solvents. If the further compound comprises a solvent, this mixture is referred to herein as a formulation. However, the further compound can also be at least one further organic or inorganic compound which is also used in the electronic device, for example an emitting compound and/or a matrix material. Preferably, it can be provided that at least one further compound is selected from the group consisting of fluorescent emitters, phosphorescent emitters, emitters which exhibit TADF, host materials, electron transport materials, electron injection materials, hole conductor materials, hole injection materials, electron blocking materials and hole blocking materials, preferably host materials.

The present invention further provides for the use of a compound according to the invention in an electronic device, in particular in an organic electroluminescent device. Preferably, the compounds according to the invention are used in an electronic device as an emitter, host material, hole-conductor material, hole-injection material, electron-blocking material, electron-transport material, electron-injection material, or hole-blocking material. The preferred use depends on the groups the compound contains; in this context, reference is made to the above and following description of the groups the compounds may contain.

A further object of the present invention is the use of an oligomer, polymer or dendrimer according to the invention in an electronic device, wherein the preferred uses set out above for the compounds according to the invention apply accordingly. The present invention further provides an electronic device comprising at least one compound according to the invention. The present invention further provides an electronic device comprising at least one oligomer, polymer, or dendrimer according to the invention, wherein the embodiments set out below or above for a compound according to the invention also apply accordingly to an oligomer, polymer, or dendrimer according to the invention. An electronic device within the meaning of the present invention is a device which contains at least one layer containing at least one organic compound. The component can also contain inorganic materials or layers composed entirely of inorganic materials.

Particularly preferably, the electronic device is selected from the group consisting of organic electroluminescent devices (OLEDs, sOLEDs, PLEDs, LECs, etc.), preferably organic light-emitting diodes (OLEDs), organic light-emitting diodes based on small molecules (sOLEDs), organic light-emitting diodes based on polymers (PLEDs), light-emitting electrochemical cells (LECs), organic laser diodes (O-lasers), “organic plasmon emitting devices” (D. M. Koller et al., Nature Photonics 2008, 1- 4); 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), organic optical detectors, organic photoreceptors, organic field-quench devices (O-FQDs) and organic electrical sensors, preferably organic electroluminescent devices (OLEDs, sOLEDs, PLEDs, LECs, etc.), particularly preferably organic light-emitting diodes (OLEDs), organic light-emitting diodes based on small molecules (sOLEDs), organic light-emitting diodes based on polymers (PLEDs), in particular phosphorescent OLEDs.

The organic electroluminescent device contains a cathode, an anode, and at least one emitting layer. In addition to these layers, they 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. Likewise, interlayers can 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, resulting in overall white emission, 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 displaying blue, green and orange or red emission. The organic electroluminescent device according to the invention may also be a tandem electroluminescent device, in particular for white-emitting OLEDs.

The compound according to the invention can be used in different layers, depending on the precise structure. An organic electroluminescent device comprising a compound according to formula (I) or the preferred embodiments described above is preferred in an emitting layer as a matrix material for phosphorescent emitters or for emitters exhibiting TADF (thermally activated delayed fluorescence), in particular for phosphorescent emitters. Furthermore, the compound according to the invention can also be used in an electron-transport layer and/or in a hole-blocking layer. The compound according to the invention is particularly preferably used as a matrix material for phosphorescent emitters, in particular for red, orange, blue, green, or yellow, preferably for blue or green phosphorescent emitters, in an emitting layer, as a host material, electron-transport material, or electron-injection material. or hole-blocking material. In a further preferred embodiment, the compound according to the invention can be used as a matrix material for phosphorescent emitters, in particular for red, orange, blue, green, or yellow, preferably for blue or green phosphorescent emitters, in an emitting layer, as a host material, hole-conductor material, hole-injection material, or electron-blocking material. Furthermore, the compound according to the invention can be used in an organic electroluminescent device as a fluorescent emitter, an emitter that exhibits TADF, or as a phosphorescent emitter, wherein the phosphorescent emitter used is preferably a previously described metal complex, which is likewise a subject of the present invention.

Preferably, it can be provided that the organic electroluminescent device comprises at least one emission layer and at least one electron transport layer and the electron transport layer contains the compound according to the present invention.

Furthermore, it can preferably be provided that the organic electroluminescent device comprises at least one emission layer and the emission layer contains a compound according to the present invention, preferably a metal complex according to the invention as a phosphorescent emitter, or a compound according to the invention which can be used as a fluorescent emitter or as an emitter which exhibits TADF.

If the compound according to the invention is used as a matrix material in an emitting layer, it is preferably used in combination with one or more emitters. The emitter(s) can fluoresce or phosphoresce. Preferably, the compound according to the invention is used as a matrix material for one or more phosphorescent compounds (triplet emitters). Phosphorescence in the sense of this invention is understood to mean luminescence from an excited state with higher spin multiplicity, i.e., a spin state > 1 (triplet, quintet, etc.), in particular from a excited triplet state (triplet emitter). For the purposes of this application, all luminescent complexes with transition metals or lanthanides, in particular all iridium, platinum, and copper complexes, are considered 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.

In one embodiment of the invention, the compound according to the invention is used as the sole matrix material (“single host”) for emitters, preferably phosphorescent emitters.

A further 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 another matrix material. Suitable matrix materials that 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 boronate 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, zinc complexes, e.g. 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. B. according to WO 2011/042107, WO 2011/060867, WO 2011/088877 and WO 2012/143080, triphenylene derivatives, e.g. according to WO 2012/048781, dibenzofuran derivatives, e.g. according to WO 2015/169412, WO 2016/015810, WO 2016/023608, WO 2017/148564 or WO 2017/148565 or biscarbazoles, e.g. according to JP 3139321 B2.

The present invention also relates to a mixture selected from a combination of the above-mentioned host materials, which contains at least one phosphorescent emitter.

Likewise, another phosphorescent emitter, which emits at a shorter wavelength than the actual emitter, can be present in the mixture as a co-host. Particularly good results are achieved when a red-phosphorescent emitter is used as the emitter and a yellow-phosphorescent emitter is used as the co-host in combination with the compound according to the invention.

Furthermore, a compound can be used as co-host which does not participate, or does not participate to a significant extent, in charge transport, as described, for example, in WO 2010/108579. In particular, compounds which have a large band gap and themselves do not participate, or at least do not participate to a significant extent, in the charge transport of the emitting layer are suitable as co-matrix material in combination with the compound according to the invention. Such materials are preferably pure hydrocarbons. Examples of such materials can be found, for example, in WO 2009/124627 or WO 2010/006680. In this context, it should be noted that compounds according to the invention without special functional groups, for example hole transport groups and/or electron transport groups, have advantageous properties. Particularly suitable phosphorescent compounds (= triplet emitters) are compounds that emit light upon suitable excitation, preferably in the visible range, and 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. Compounds containing copper, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, iridium, palladium, platinum, silver, gold, or europium are preferably used as phosphorescent emitters, in particular compounds containing iridium or platinum.

Examples of the emitters described above can be found in the applications WO 00/70655, WO 2001/41512, WO 2002/02714, WO 2002/15645, EP 1191613, EP 1191612, EP 1191614, WO 05/033244, WO 05/019373, 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 and WO 2018/011186. In general, all phosphorescent complexes as used according to the prior art for phosphorescent electroluminescent devices 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 in the following table.

The phosphorescent dopants presented above by way of example may preferably have structures according to formula (I) or preferred embodiments of these structures, these compounds having the structures according to the invention representing particularly preferred metal complexes of the present invention.

The compounds according to the invention are particularly suitable as matrix materials for phosphorescent emitters in organic electroluminescent devices, as described, for example, in WO 98/24271, US 2011/0248247 and US 2012/0223633. In these multi-colored display components, an additional blue emission layer vapor-deposited over all pixels, even those with a color other than blue.

A further embodiment of the present invention is the use of the compound according to the invention as a matrix material for fluorescent emitters. Fluorescent emitters are widely known in the art, with preferred examples of fluorescent emitters being listed in the following table. The fluorescent emitters presented above by way of example may comprise substituents, so that the compounds presented correspond to formula (I) or represent preferred embodiments of these compounds, wherein these compounds according to the invention represent particularly preferred fluorescent emitters of the present invention.

A further embodiment of the present invention is the use of the compound according to the invention as a matrix material for emitters exhibiting TADF. A further embodiment of the present invention is the use of the compound according to the invention as a matrix material for a fluorescent emitter. Emitters exhibiting TADF are widely known in the art, with preferred examples of fluorescent emitters being listed in the table below.

The emitters exhibiting TADF set out above by way of example may comprise substituents so that the compounds set out correspond to formula (I) or represent preferred embodiments of these compounds, wherein these compounds according to the invention represent particularly preferred emitters exhibiting TADF of the present invention.

In a further embodiment of the invention, the organic electroluminescent device according to the invention does not contain a separate hole injection layer and/or hole transport layer and/or hole blocking layer and/or electron transport layer, i.e. the emitting layer directly adjoins the hole injection layer or the anode, and/or the emitting layer directly adjoins the electron transport layer or the electron injection layer or the cathode, as described, for example, in WO 2005/053051. Furthermore, it is possible to use a metal complex that is the same as or similar to the metal complex in the emitting layer as a hole transport or hole injection material directly adjacent to the emitting layer, as described, for example, in WO 2009/030981. In the further layers of the organic electroluminescent device according to the invention, all materials commonly used in the prior art can be used. Therefore, the skilled person can, without inventive step, use all materials known for organic electroluminescent devices in combination with the compounds according to formula (I) according to the invention or the preferred embodiments described above.

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 Vapor Phase Deposition) process or by 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 Vapor Jet Printing) process, in which the materials are applied directly through a nozzle and thus patterned.

Also preferred is an organic electroluminescent device characterized in that one or more layers are produced from solution, such as by spin coating, or by any printing process, such as screen printing, flexographic printing, offset printing, LITI (Light Induced Thermal Imaging, thermal transfer printing), inkjet printing, or nozzle printing. Soluble compounds are required for this, which are obtained, for example, by suitable substitution. Furthermore, hybrid processes are 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 organic electroluminescent devices containing the compounds according to the invention.

The compounds of the invention and the organic electroluminescent devices of the invention are distinguished from the prior art in particular by a low refractive index (RI). Furthermore, these compounds and the organic electroluminescent devices obtainable therefrom exhibit an improved lifetime. The other electronic properties of the electroluminescent devices, such as efficiency or operating voltage, remain at least equally good. In a further variant, the compounds of the invention and the organic electroluminescent devices of the invention are distinguished from the prior art in particular by improved efficiency and/or operating voltage and a longer lifetime.

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

1 . Electronic devices, in particular organic electroluminescent devices containing compounds according to formula (I) or the preferred embodiments described above and below, in particular as emitters, as matrix materials, as hole-conducting materials or as electron-conducting materials, have excellent efficiency. Compounds according to the invention according to formula (I) or the preferred embodiments described above and below bring about low operating voltage when used in electronic devices. Electronic devices, in particular organic electroluminescent devices comprising compounds of the formula (I) or the preferred embodiments set out above and below, in particular as emitters, as matrix material, as hole-conducting materials or as electron-conducting materials, have a very good lifetime. In particular, these compounds bring about low roll-off, i.e. a low drop in the power efficiency of the device at high luminances. The compounds of the formula (I) according to the invention or the preferred embodiments set out above and below display very high stability and lifetime. Electronic devices, in particular organic electroluminescent devices comprising compounds of the formula (I) or the preferred embodiments set out above and below, in particular as emitters, as matrix material, as hole-conducting materials or as electron-conducting materials, have very low refractive indices. Electronic devices, in particular organic electroluminescent devices containing compounds according to formula (I) or the preferred embodiments described above and below, in particular as emitters or as matrix materials, have a very high color purity. Compounds according to formula (I) or the preferred embodiments described above and below can prevent the formation of optical loss channels in electronic devices, in particular organic electroluminescent devices. As a result, these Devices are characterized by high PL and thus high EL efficiency of emitters and excellent energy transfer from the matrices to dopants.

7. Compounds according to formula (I) or the preferred embodiments described above and below have excellent glass film formation.

8. Compounds according to formula (I) or the preferred embodiments described above and below form very good films from solutions.

These advantages mentioned above are not accompanied by an excessive deterioration of the other electronic properties.

It should be noted that variations of the embodiments described in the present invention fall within the scope of this invention. Any feature disclosed in the present invention may, unless explicitly excluded, be replaced by alternative features serving the same, equivalent, or similar purpose. Thus, unless otherwise stated, any feature disclosed in the present invention is to be considered an example of a generic series or an equivalent or similar feature.

All features of the present invention may be combined with each other in any way, unless certain features and/or steps are mutually exclusive. This applies in particular to preferred features of the present invention. Likewise, features of non-essential combinations may be used separately (and not in combination).

It should also be noted that many of the features, and in particular those of the preferred embodiments of the present invention, are inventive in themselves and are not to be considered merely as part of the embodiments of the present invention. For these features, independent protection may be sought in addition to or alternatively to any currently claimed invention.

The teaching of technical action disclosed in the present invention can be abstracted and combined with other examples.

The invention is further illustrated by the following examples, without intending to limit it. From these descriptions, one skilled in the art can practice the invention within the entire disclosed scope and, without inventive step, prepare further compounds according to the invention and use them in electronic devices or apply the method according to the invention.

Examples:

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

A) Synthesis of the synthons S and the compounds E according to the invention:

Example S1 :

1) Level S1a:

Preparation according to J. Mikolajv et al., Synthetic Communications (1983), 13(1 ), 53-62. Preparation: 20.2 g (100 mmol) octahydro-3,5,1 ,7-[1 ,2,3,4]butanetetrayl-naphthalen-2(1 H)-one [30545-23-4] and 35 ml (105 mmol) methylmagnesium bromide, 3 M in dimethyl ether.

Yield: 19.8 g (90 mmol) 90%; purity: approximately 98% ¹ H-NMR.

2) Level S1

Preparation analogous to CN 115490601 . Preparation: 21 .8 g (100 mmol) S1 a and

23.6 g (150 mmol) bromobenzene [108-86-1 ], yield: 22.1 g

(62 mmol) 62%; purity: approx. 98% ¹ H-NMR

The following connections can be represented analogously.

Example S100:

Preparation analogous to US 2022/0220049, page 80 "Intermediates lA-1 and lA-2". Preparation: 20.2 g (100 mmol) octahydro-3,5,1,7-[1,2,3,4]butanetetraylnaphthalen-2(1H)-one [30545-23-4] and 26.8 g (100 mmol) 2-bromo-4'-chloro-1,1'-biphenyl [179526-95-5], yield: 25.0 g (67 mmol) 67%; purity: approx. 98% ^1H NMR.

The purification and, if appropriate, isomer separation of the crude products of the compounds E according to the invention is carried out by chromatography (Torrent column machine from A. Semrau) and/or repeated hot extraction crystallization (conventional organic solvents or combinations thereof, preferably acetonitrile-DCM, 1:3 to 3:1 vv) as well as fractional sublimation or annealing under high vacuum.

Example S200:

Preparation analogous to Y. Hu et al., ACS Appl. Polymer Mater. 2019, 1 (2), 221 , Compound 8. 1.05 eq of NBS was used per CH function para to the N atom. The crude product was purified by chromatography (Torrent column analyzer from A. Semrau). Batch: 50.4 g (100 mmol) of E14. Yield: 58.7 g (89 mmol) (89%). Purity: 97% by ¹ H NMR.

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

Example S300:

Procedure analogous to WO2012068589. Instead of PCys, S-Phos can be used for chlorides. 35.7 g (100 mmol) of S1 was used. Yield: 36.8 g (91 mmol) 91%; purity approx. 97% according to ¹ H NMR.

Example E100:

Preparation analogous to a) SS Reddy et al., Dyes and Pigments, (2016), 134, 315, or b) X. Liu et al., Angew. Chem. IE, 2021, 60(5), 2455 or c) W.- L. Tsai et al., Chem. Commun, 2015, 51 (71), 13662. According to a), batch: 35.7 g (100 mmol) S1 and 32.1 g (100 mmol) bis(4-biphenylyl)amine [102113-98-4]. Purification is carried out by repeated hot extraction crystallization (usual organic solvents or combinations thereof, preferably acetonitrile-DCM, 1:3 to 3:1 vv) or chromatography and fractional sublimation or annealing in High vacuum. Yield: 49.9 g (83 mmol) 83%; Purity: > 99.9% by HPLC.

Example E200:

A well-stirred solution of 35.7 g (100 mmol) S1 , 44.1 g (110 mmol) B-[4-[bis([1,1 '-biphenyl]-4-yl)amino]phenyl]boronic acid [943836-24-6], 42.4 g (200 mmol) tripotassium phosphate [7778-53-2], 1.16 g (1 mmol)

Tetrakis(triphenylphosphine)palladium(0) [14221-01-3], 300 ml of toluene, 100 ml of dioxane, and 300 ml of water are heated under reflux for 16 h. After cooling, the organic phase is separated, washed three times with 300 ml of water each, once with 300 ml of saturated sodium chloride solution, and dried over magnesium sulfate. The drying agent is removed by filtration, the filtrate is evaporated to dryness, and the residue is chromatographed (Torrent column chromatography machine from A. Semrau). Further purification of the crude product is carried out by chromatography and/or repeated hot extraction crystallization (common organic solvents or combinations thereof, preferably acetonitrile-DCM, 1:3 to 3:1 vv) as well as fractional sublimation or annealing under high vacuum. Yield: 49.5 g (73 mmol) 73%; Purity: approx. 99.9% by HPLC.

Analogously, the following compounds can be prepared by adjusting the stoichiometry of the reactants, whereby when chlorides are used instead of tetrakis(triphenylphosphine)-palladium(0), 1 mmol palladium acetate and 2 mmol S-Phos are used.

Example E300:

A solution of 37.1 g (105 mmol) of S124 in 300 ml of DMF is treated portionwise with 2.4 g (100 mmol) of sodium hydride (caution: evolution of hydrogen!). Then, 37.8 g (110 mmol) of 2-[1,1-biphenyl]-4-yl-4-chloro-6-phenyl-1,3,5-triazine [1472062-94-4] is added, and the mixture is stirred for 2 h at ambient temperature and for 3 h at 50 °C. While stirring, 2000 ml of water is added dropwise. The precipitated solid is filtered off, washed three times with 100 ml of water each time, twice with 100 ml of ethanol each time, and dried in vacuo. The solid is dissolved in dichloromethane and filtered through a silica gel bed pre-slurried with DCM. The filtrate is slowly concentrated in a rotary evaporator, continuously replacing the distilled DCM with ethanol. The crystallized product is separated, washed twice with 50 ml of ethanol each time, and concentrated under vacuum. dried. Further purification of the crude product is carried out by chromatography and/or repeated hot extraction crystallization (common organic solvents or combinations thereof, preferably acetonitrile-DCM, 1:3 to 3:1 vv) as well as fractional sublimation or annealing under high vacuum. Yield: 44.7 g (68 mmol) 68%; Purity: approx. 99.9% by HPLC.

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, using Merck Extran cleaner) coated with 50 nm thick structured ITO (indium tin oxide) 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 Devices - BF:

The compounds E according to the invention can be used in the hole transport layer (HTL), electron blocking layer (EBL), Hole blocking layer (HBL) and the electron transport layer (ETL) are used. All materials are thermally evaporated 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(s) by co-evaporation in a certain volume fraction. A specification such as SMB:D (95%:5%) means that the material SMB is present in a volume fraction of 95% and the dopant D is present in a volume fraction of 5% in the layer. 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 or refer to the previously presented synthesis examples.

The OLEDs are characterized as standard. For this purpose, the electroluminescence spectra, current efficiency (measured in cd/A), power efficiency (measured in λm/W), and external quantum efficiency (EQE, measured in percent) are determined as a function of luminance, calculated from current-voltage-luminance characteristics (IUL characteristics) assuming a Lambertian radiation pattern. The EQE (%) and voltage (V) are expressed at a luminance of 1000 cd/ ^m².

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), made of HTM1, 180 nm

Electron blocking layer (EBL), see Table 1

Emission layer (EML), see Table 1

Hole blocking layer (HBL), 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 components:

The compounds E according to the invention can be used in the hole transport layer (HTL), electron blocking layer (EBL), hole blocking layer (HBL), electron transport layer (ETL), and in the emission layer (EML) as hole-conducting or electron-conducting matrix material (host material) (hTMM or eTMM). 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 admixed to the matrix material(s) by co-evaporation in a specific volume fraction. A specification such as M1:M2:Ir (55%:35%:10%) means that the material M1 is present in the layer in a volume fraction of 55%, M2 in a volume fraction of 35%, and Ir in a volume fraction 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 or refer to the synthesis examples presented previously.

The OLEDs are characterized as standard. For this purpose, the electroluminescence spectra, current efficiency (measured in cd/A), power efficiency (measured in λm/W), and external quantum efficiency (EQE, measured in percent) are determined as a function of luminance, calculated from current-voltage-luminance characteristics (IUL characteristics) assuming a Lambertian radiation pattern. The EQE (%) and voltage (V) are expressed at a luminance of 1000 cd/ ^m².

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) made of HTM1, 180 nm for blue, 50 nm for green, yellow and red

Electron blocking layer (EBL), see Table 3

Emission layer (EML), see Table 3

Hole blocking layer (HBL), see Table 3

Electron transport layer (ETL), see Table 3

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. Compound according to formula (I), where the symbols are: U stands for Ar or R ^b , the same or different at each occurrence; z stands for 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 14, 15, 16, 17 or 18, the same or different at each occurrence; Ar is, on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms which may be substituted by one or more radicals R other than H, where two radicals Ar which bind to the same C atom may also be linked by a single bond or a bridge selected from B(R), C(R)2, Si(R) ₂ , C=O, C=NR, C=C(R) ₂ , RC=CR, O, S, S=O, _SO2 , N(R), P(R), P(=O)R, an ortho-linked phenylene group which may be substituted by one or more radicals R other than H, where the radical Ar may be coordinated to a transition metal; R ^a is, identically or differently at each occurrence, H, D, F, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, each of which may be substituted by one or more radicals R ² other than H; R ^b is, identically or differently at each occurrence, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 20 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 C atoms, each of which may be substituted by one or more radicals R ² other than H, where the radical R ^b may form a ring system with the group U; R is, identical or different at each occurrence, H, D, OH, F, CI, Br, I, CN, NO2, N(Ar') ₂ , N( ^R1 ) ₂ , C(=O)N(Ar') ₂ , C(=O)N( ^R1 ) ₂ , C(Ar') ₃ , C( ^R1 ) ₃ , Si(Ar') ₃ , Si( ^R1 ) ₃ , B(Ar') ₂ , B( ^R1 ) ₂ , C(=O)Ar', C(=O) ^R1 , P(=O)(Ar') ₂ , P(=O)( ^R1 ) ₂ , P(Ar') ₂ , P( ^R1 )2, S(=O)Ar', S(=O) ^R1 , S(=O) _2Ar ', S(=O) _2R1 ^, OSO ₂ Ar', OSO2R ¹ , a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms or an alkenyl or alkynyl group having 2 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 C atoms, where the alkyl, alkoxy, thioalkoxy, alkenyl or alkynyl group may each be substituted by one or more radicals R ¹ other than H, where one or more non-adjacent CH2 groups are substituted by R ¹ C=CR ¹ , C^C, Si(R ¹ ) ₂ , C=O, C=S, C=Se, C=NR ¹ , -C(=O)O-, -C(=O)NR ¹ -, NR ¹ , P(=O)(R ¹ ), -O-, -S-, SO or SO2, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, each of which may be substituted by one or more radicals R ¹ other than H, or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R ¹ other than H, two radicals R can also form a ring system with one another or a radical R can form a ring system with a further group, in particular a group U or a radical R ^b , the radical R can be coordinated to a transition metal; Ar' is at each occurrence, identically or differently, an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R ¹ other than H, two radicals Ar' which are bonded to the same C atom, Si atom, N atom, P atom or B atom may also be bridged to one another by a single bond or a bridge selected from B(R ¹ ), C(R ¹ ) 2, Si(R ¹ ) 2, C=O, C=NR ¹ , C=C(R ¹ ) ₂ , O, S, S=O, SO ₂ , N(R ¹ ), P(R ¹ ) and P(=O)R ¹ , the radical Ar' may be coordinated to a transition metal; R ¹ is, identically or differently on each occurrence, H, D, F, CI, Br, I, CN, NO 2, N(Ar”) ₂ , N(R ² ) ₂ , C(=O)Ar”, C(=O)R ² , P(=O)(Ar”) ₂ , P(Ar”) ₂ , B(Ar”) ₂ , B(R ² ) ₂ , C(Ar”) ₃ , C(R ² ) ₃ , Si(Ar”) ₃ , Si(R ² ) ₃ , a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 40 C atoms or an alkenyl group having 2 to 40 C atoms, each of which is substituted by one or more radicals R ² other than H may be substituted, where one or more non-adjacent CH2 groups may be replaced by ^-R2C = ^CR2- , -C^C-, Si( ^R2 ) ₂ , C=O, C=S, C=Se, C= ^NR2 , -C(=O)O-, -C(=O) ^NR2- , ^NR2 , P(=O)( ^R2 ), -O-, -S-, SO or SO2 and where one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO2, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, each of which may be substituted by one or more radicals ^R2 other than H, or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals ^R2 other than H, or an aralkyl or Heteroaralkyl group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R ² other than H, or a combination of these systems; two or more radicals R ¹ may form a ring system with one another, one or more radicals R ¹ may form a ring system with another part of the compound, the radical R ¹ may be coordinated to a transition metal; Ar" is, on each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms which may be substituted by one or more radicals R ² other than H, where two radicals Ar" which are bonded to the same C atom, Si atom, N atom, P atom or B atom may also be bridged to one another by a single bond or a bridge selected from B(R ² ), C(R ² ) 2, Si(R ² ) 2, C=O, C=NR ² , C=C(R ² ) ₂ , O, S, S=O, SO ₂ , N(R ² ), P(R ² ) and P(=O)R ² , where the radical Ar" may be coordinated to a transition metal; R ² is selected, identically or differently at each occurrence, from the group consisting of H, D, F, CN, an aliphatic hydrocarbon radical having 1 to 20 C atoms or an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, in which one or more H atoms may be replaced by D, F, CI, Br, I or CN and which may be substituted by one or more alkyl groups each having 1 to 4 carbon atoms, where two or more substituents R ² may form a ring system with one another. 2. A compound according to claim 1, characterized in that the group Ar is selected, identically or differently on each occurrence, from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthalene, indole, benzofuran, benzothiophene, carbazole, benzimidazolobenzimidazole, dibenzofuran, dibenzothiophene, indenocarbazole, indolocarbazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, isoquinoline, quinazoline, quinoxaline, phenanthrene or triphenylene, which may each be substituted by one or more radicals R other than H. 3. A compound according to claim 1 or 2, characterized in that the group Ar is selected, identically or differently at each occurrence, from structures of the formulas (Ar'-1) to (Ar'-29), where the symbols used are: Y ¹ is, identically or differently at each occurrence, O, S, NR, BR, Si(R)2, C(R)2, C=C(R)2 or an ortho-linked phenylene group which may be substituted by one or more R radicals other than H; k is, independently at each occurrence, 0 or 1; i is, independently at each occurrence, 0, 1 or 2; j is, independently at each occurrence, 0, 1, 2 or 3; h is, independently at each occurrence, 0, 1, 2, 3 or 4; g is, independently at each occurrence, 0, 1, 2, 3, 4 or 5; R has the meaning given above, in particular for claim 1, and the dashed bond marks the attachment position. 4. A compound according to one or more of claims 1 to 3, characterized in that the compound has at least one of the following formulas (I-1) to (I-7), Formula (I-7) wherein the symbols z, R ^a and R ^b have the meanings given in claim 1 and the following applies to the other symbols: Y is, identically or differently at each occurrence, a single bond, O, S, NR, BR, Si(R) ₂ , C(R) ₂ , (R) ₂ C=C(R) ₂ , P(R), P(=O)R, C=C(R) ₂ or an ortho-linked phenylene group which may be substituted by one or more radicals R other than H; Y ^a is the same or different at each occurrence: 0, S, NR, BR; X is, at each occurrence, identically or differently, CR or N, where R has the meaning given in claim 1. 5. A compound according to one or more of claims 1 to 4, characterized in that the compound corresponds to at least one of the following formulas (11-1) to (11-16), Formula (11-15) Formula (11-16) where the symbols z, R, R ^a and R ^b have the meanings given in claim 1 and the other symbols are as follows: Y is, identically or differently at each occurrence, a single bond, O, S, NR, BR, Si(R) ₂ , C(R) ₂ , (R) ₂ C=C(R) ₂ , P(R), P(=O)R, C=C(R) ₂ or an ortho-linked phenylene group which may be substituted by one or more R radicals other than H; i is, independently at each occurrence, 0, 1 or 2; j is, independently at each occurrence, 0, 1, 2 or 3; h is, independently at each occurrence, 0, 1, 2, 3 or 4; and g is, independently at each occurrence, 0, 1, 2, 3, 4 or 5. 6. A compound according to one or more of claims 1 to 5, characterized in that the compound corresponds to the following formula (III-1) or (III-2), Formula (III-1) Formula (III-2) where the symbols R and R ^a have the meanings given in claim 1 and the following applies to the further symbols: Y ² is, identically or differently on each occurrence, B(R ¹ ), C(R ¹ )2, Si(R ¹ ) ₂ , C=O, C=NR ¹ , C=C(R ¹ ) ₂ , O, S, S=O, S0 ₂ , N(R ¹ ), P(R ¹ ) and P(=O)R ¹ ; Y ³ is, at each occurrence, the same or different, B(R ¹ ), C(R ¹ ) 2 , Si(R ¹ ) ₂ , O=O, C=NR ¹ , C=C(R ¹ ) 2, O, S, S=O, SO2, N(R ¹ ), P(R ¹ ) and P(=O)R ¹ ; and j is, independently at each occurrence, 0, 1, 2 or 3. 7. A compound according to at least one of the preceding claims, characterized in that the group R ^a stands for H, D, methyl, ethyl, propyl, where these groups may be deuterated. 8. A compound according to at least one of the preceding claims, characterized in that the group R ^b represents methyl, ethyl, propyl, butyl or pentyl, wherein these groups may be deuterated. 9. A compound according to at least one of the preceding claims, characterized in that the compound comprises at least one hole transport group. 10. A compound according to at least one of the preceding claims, characterized in that the compound comprises at least one electron transport group. 11. A compound according to at least one of the preceding claims, characterized in that the compound comprises at least one emitting group. 12. Oligomer, polymer or dendrimer containing one or more compounds according to one of claims 1 to 11, wherein instead of a hydrogen atom or a substituent, one or more bonds of the compounds to the polymer, oligomer or dendrimer are present. 13. A formulation comprising at least one compound according to one or more of claims 1 to 11 or an oligomer, polymer or dendrimer according to claim 12 and at least one further compound, wherein the further compound is preferably selected from one or more solvents. 14. A composition comprising at least one compound according to one or more of claims 1 to 11 or an oligomer, polymer or dendrimer according to claim 12 and at least one further compound selected from the group consisting of fluorescent emitters, phosphorescent emitters, emitters exhibiting TADF, host materials, electron transport materials, electron injection materials, hole conductor materials, hole injection materials, electron blocking materials and hole blocking materials. 15. A process for the preparation of a compound according to one or more of claims 1 to 11, characterized in that a Compound with an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms is synthesized and reacted with a ketone which has a pentacyclic alkyl group in the alpha position. 16. Use of a compound according to one or more of claims 1 to 11 or an oligomer, polymer or dendrimer according to claim 12 in an electronic device. 17. An electronic device comprising at least one compound according to one or more of claims 1 to 11 or an oligomer, polymer, or dendrimer according to claim 12.