WO2026008275A1

WO2026008275A1 - Materials for organic light emitting diodes

Info

Publication number: WO2026008275A1
Application number: PCT/EP2025/066505
Authority: WO
Inventors: Rouven LINGE; Martin Kraska; Natalie TOBER; Christian EICKHOFF
Original assignee: Merck Patent GmbH
Current assignee: Merck Patent GmbH
Priority date: 2024-07-04
Filing date: 2025-06-13
Publication date: 2026-01-08
Anticipated expiration: 2027-01-04
Also published as: WO2026008276A1

Abstract

The present invention concerns an OLED material, which is compound according to formula (1), its use in an electronic device, in particular in an organic light-emitting device (OLED), a method for its preparation, and an electronic device, in particular an OLED, comprising the compound according to the formula (1).

Description

Materials for organic light emitting diodes

Electronic devices in the context of this application are understood to mean what are called organic electronic devices, which comprise organic semiconductor materials as functional materials. More particularly, these are understood to mean OLEDs (organic electroluminescent devices, organic light emitting diodes). The term OLED is understood to mean an electronic device which has one or more layers comprising organic compounds and emits light on application of electrical voltage. The construction and general principle of function of OLEDs are known to those skilled in the art. In electronic devices, especially OLEDs, there is great interest in an improvement in the performance data.

A great influence on the performance data of electronic devices is possessed by emission layers and layers having a hole-transporting function. Novel compounds are also being sought for use in these layers, especially hole-transporting compounds and compounds that can serve as hole-transporting matrix material, especially for phosphorescent emitters, in an emitting layer. For this purpose, especially compounds that have a high glass transition temperature and high decomposition temperature, high stability, and high conductivity for holes are being sought for. A high stability of the compound is a prerequisite for achieving a long lifetime of the electronic device. There is moreover a need to find compounds the use of which in electronic devices results in an improvement of the performance data of the devices, especially in a high efficiency, a long lifetime and a low operating voltage, a low lateral leakage current, e.g. leakage current to neighboring pixels that are switched off, as well as a low capacitance/voltage signal, as described for example in more detail in WO 2024/133366. In particular the latter is of great importance for the general charging behaviour of an OLED.

In the prior art, triarylamine compounds, such as for example fluoreneamines, are known as hole transport materials and hole-transporting matrix materials for electronic devices. Examples are 9,9-diarylfluorenes which are substituted with diarylamino groups, such as disclosed in WO 2009/124627, WO 2019/151682, ON 111440156, WO 2024/021264, US 2016/0359113 and WO 2021/170886. Still, there remains room for improvement in respect of the above-mentioned properties.

It has now been found that aromatic amines of the formula (1) below are of excellent suitability for use in electronic devices. They are especially suitable for use in OLEDs, and even more particularly therein for use as hole transport materials and for use as holetransporting matrix materials, especially for phosphorescent emitters. The compounds lead to high lifetime, high efficiency and low operating voltage of the devices, as well as a low lateral current. Further preferably, these compounds have a high glass transition temperature, high thermal stability, i.e. high decomposition temperature, low sublimation temperature, good solubility, good synthetic accessibility and high conductivity for holes.

The present application is thus directed to a compound of the following formula (1),

Formula (1) where the structure can be partially or fully deuterated and the following applies to the symbols and indices:

Ar¹, Ar², Ar³ are the same or different at each instance and are each independently an aromatic or heteroaromatic ring system with 5 to 30 aromatic ring atoms, each of which can be partially or fully deuterated and can be substituted by one or more substituents R;

L is an aromatic ring system having 6 to 24 aromatic ring atoms which can be substituted with one or more R radicals and which can be partially or fully deuterated; R is, identically or differently at each instance, F, Cl, Br, I, CN, Si(R¹)a, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms or a branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 20 C atoms wherein the alkyl, alkoxy or thioalkyl group can be substituted with one or more radicals R¹, an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms which can be substituted with one or more radicals R¹ or an aryloxy or heteroaryloxy group which can be substituted with one or more radicals R¹ or a combination of these systems; where all of these groups can be partially or fully deuterated; where two or more adjacent radicals R may be connected to each other to form a ring;

R¹ is, identically or differently at each instance, F, an alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms where one ore more H atoms of the alkyl, alkoxy or thioalkyl group can be replaced by F, or an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms; where all of these groups can be partially or fully deuterated; where two or more adjacent radicals R¹ may be connected to each other to form a ring; n is, identically or differently at each instance, 0, 1 , 2, 3 or 4; m is, identically or differently at each instance, 0, 1 , 2 or 3; o is 0, 1 , 2 or 3; p is 0, 1 , 2, 3 or 4; q is O or l .

The following definitions apply to the chemical groups used as general definitions. They apply insofar as no more specific definitions are given.

The numbering of the positions of dibenzofuran, dibenzothiophene, carbazole and fluorene are as follows:

An aryl group here is taken to mean either a single aromatic ring, for example benzene, or a condensed aromatic polycycle, for example naphthalene, phenanthrene, or anthracene. A condensed aromatic polycycle in the sense of the present application consists of two or more single aromatic rings which are condensed with one another. An aryl group in the sense of this invention contains 6 to 30 aromatic ring atoms. An aryl group does not contain any heteroatoms as aromatic ring atoms, but only carbon atoms. A heteroaryl group here is taken to mean either a single heteroaromatic ring, such as pyridine, pyrimidine or thiophene, or a condensed heteroaromatic polycycle, such as dibenzofuran or carbazole. A condensed heteroaromatic polycycle in the sense of the present application consists of two or more single aromatic or heteroaromatic rings, which are condensed with one another, where at least one of the two or more aromatic or heteroaromatic rings is a heteroaromatic ring. A heteroaryl group in the sense of this invention contains 5 to 30 aromatic ring atoms, at least one of which is a heteroatom. The heteroatoms are preferably selected from N, O and S.

An aryl or heteroaryl group, which may in each case be substituted by the above- mentioned radicals, is taken to mean, in particular, a group derived from benzene, naphthalene, anthracene, phenanthrene, pyrene, dihydropyrene, chrysene, perylene, fluoranthene, benzanthracene, benzophenanthrene, tetracene, pentacene, benzopyrene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8- quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, benzimidazolo[1 ,2-a]benzimidazole, naphthimidazole, phenanthrimidazole, pyridimi- dazole, pyrazinimidazole, quinoxalinimidazole, oxazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, 1 ,2-thiazole, 1 ,3-thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine, benzopyrimidine, quinoxaline, pyrazine, phenazine, 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.

An aromatic ring system in the sense of this invention is a system which does not necessarily contain only aryl groups, but which may additionally contain one or more nonaromatic rings, which are condensed with at least one aryl group. Such non-aromatic rings contain exclusively carbon atoms as ring atoms. Examples of groups embraced by such definition are tetrahydronaphthalene, fluorene, and spirobifluorene. Furthermore, the term aromatic ring system is understood to embrace systems consisting of two or more aromatic ring systems which are connected to each other via single bonds, such as biphenyl, terphenyl, 7-phenyl-2-fluorenyl and quaterphenyl. An aromatic ring system in the sense of this invention contains 6 to 30 C atoms and no heteroatoms as ring atoms of the ring system. An aromatic ring system in the sense of this application does not comprise any heteroaryl groups, as defined above.

A heteroaromatic ring system is defined in analogy to the aromatic ring system above, but with the difference that it must contain at least one heteroatom as one of the ring atoms. As it is the case for the aromatic ring system, it does not necessarily contain only aryl and heteroaryl groups, but it may additionally contain one or more non-aromatic rings, which are condensed with at least one aryl or heteroaryl group. The non-aromatic rings may contain only carbon atoms as ring atoms, or they may contain additionally one or more heteroatoms, where the heteroatoms are preferably selected from N, O and S. An example for such a heteroaromatic ring system is benzpyranyl. Furthermore, the term heteroaromatic ring system is understood to embrace systems consisting of two or more aromatic or heteroaromatic ring systems, which are connected to each other via single bonds, such as 4,6-diphenyl-2-triazinyl. A heteroaromatic ring system in the sense of this invention contains 6 to 30 ring atoms, which are selected from carbon and heteroatoms, where at least one of the ring atoms is a heteroatom. The heteroatoms are preferably selected from N, O or S.

The terms “heteroaromatic ring system” and “aromatic ring system” according to the definition of the present application differ from each other by the fact that the aromatic ring system cannot comprise any heteroatom as aromatic ring atom, whereas the heteroaromatic ring system must comprise at least one heteroaryl group. According to the above, any aryl group, as defined above, is embraced by the term “aromatic ring system”, as defined above, and any heteroaryl group, as defined above, is embraced by the term “heteroaromatic ring system”, as defined above.

An aromatic ring system having 6 to 30 aromatic ring atoms or a heteroaromatic ring system having 5 to 30 aromatic ring atoms is in particular a group which is derived from the above-mentioned aryl or heteroaryl groups, or from biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, indenofluorene, and indenocarbazole, or from any combinations of these groups.

For the purposes of the present invention, the expression “alkyl group”, if not specified further, is taken to include linear, as well as branched and/or cyclic alkyl groups. A cyclic alkyl group in the sense of the present invention embraces monocyclic, bicyclic and polycyclic groups. For the purposes of the present invention, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms is preferably taken to mean the radicals methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl or 2-ethylhexyl.

The phrase “two or more radicals may be connected to each other to form a ring” shall be understood to include the case that the two radicals are connected by a chemical bond. Additionally, the phrase shall be understood to include the case that one of the two radicals is H, this radical H is removed, and the other of the two radicals forms a ring by being connected to the position, to which this radical H was initially bonded.

The naphthyl group in the compound of formula (1) may be connected via its 1 -position, resulting in a compound of the following formula (2), or via its 2-position, resulting in a compound of the following formula (3),

Formula (2) Formula (3) wherein the symbols and indices have the same meanings as defined above and the compounds can be partially or fully deuterated.

Preferably, the indices n are, identically or differently at each instance, 0, 1, 2 or 3, particularly preferably 0, 1 or 2, very particularly preferably 0 or 1 and most preferred 0.

Preferably, the indices m are, identically or differently at each instance, 0, 1 or 2, particularly preferably 0 or 1 and most preferred 0.

Preferred embodiments of the compounds of formulae (2) and (3) are therefore the compounds of the following formulae (2a) and (3a), wherein the symbols and indices have the same meanings as defined above and the compounds can be partially or fully deuterated. In a further preferred embodiment of the invention, the index p = 0, i.e. the linking group L is not present. Preferred compounds are therefore the compounds of the following formulae (2b) and (3b),

Formula (2b) Formula (3b) wherein the symbols and indices have the same meanings as defined above and the compounds can be partially or fully deuterated.

Particularly preferred embodiments of the compounds of formulae (2) and (3) are compounds of the following formulae (2c) and (3c),

Formula (2c) Formula (3c) wherein the symbols have the same meanings as defined above and the compounds can be partially or fully deuterated. In a further preferred embodiment, o = 0 or 1 and p = 0, 1 or 2, preferably p = 0 or 1.

Furthermore, in a preferred embodiment, o + p = 0 or 1. Particularly preferred, o = 0 and p = 0. Preferred embodiments of the compound of formula (2) and (3) are the compounds of the formulae (2-1) to (2-7) and (3-1) to (3-7),

Formula (2-5) Formula (2-6)

Formula (3-3) Formula (3-4)

Formula (3-7) wherein the symbols and indices have the same meanings as defined above and the compounds can be partially or fully deuterated.

Preferred embodiments are the compounds of formula (2-1) to (2-7) and (3-1) to (3-7) in which the index n and m is the same or different at each instance and is 0 or 1, and particularly preferred n = 0 and m = 0.

Further preferred embodiments are the compounds of formula (2-1) to (2-7) and (3-1) to (3-7) in which the index q is the same or different at each instance and is 0 or 1, and particularly preferred q = 0.

Particularly preferred embodiments are the compounds of formula (2-1) to (2-7) and (3-1) to (3-7) in which m = 0, n = 0 and q = 0, i.e. the compounds of the following formulae (2- 1a) to (2-7a) and (3- 1a) to (3-7a), wherein the symbols have the same meanings as defined above and the compounds can be partially or fully deuterated.

Preferably, Ar¹ and Ar² are the same or different at each instance and are an aromatic ring system with 6 to 24 aromatic ring atoms, preferably with 6 to 18 aromatic ring atoms, particularly preferably with 6 to 12 aromatic ring atoms, each of which can be partially or fully deuterated and/or can be substituted by one or more substituents R, or a heteroaromatic ring system selected from dibenzofuran, dibenzothiophene, carbazole or benzofuran, each of which can be partially or fully deuterated and/or can be substituted by one or more substituents R. Preferred groups Ar¹ and Ar² are the same or different at each instance and are independently selected from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthyl, dibenzofuran, dibenzothiophene and carbazole, each of which can be partially or fully deuterated and/or substituted with one or more groups R.

In a preferred embodiment of the invention, Ar¹ is a group of the following formula (Ar¹-1),

Formula (Ar¹-1) wherein the dashed bond represents the bond to the nitrogen atom, X is selected from O, S, NR or CR2, preferably O, S or CR2 and particularly preferably O or CR2, the indices m and n and the symbol R have the same meanings as defined above and the structure can be partially or fully deuterated. In a further preferred embodiment of formula (Ar¹-1), the index n = 0 or 1 , particularly preferred 0, and the index m = 0 or 1 , particularly preferred 0. If X = O or S, the group of formula (Ar¹-1) is preferably bound via the 1- or 4-position. If X = CR2, the group of formula (Ar¹-1) is preferably bound the via the 1-, 2- or 4-position, particularly preferably via the 1- or 4-position.

For X = NR, the substituent R on the N atom is preferably an aromatic ring system having 6 to 24 aromatic ring atoms, particularly preferably 6 to 18 aromatic ring atoms and very particularly preferred 6 to 12 aromatic ring atoms, each of which can be partially of fully deuterated and/or can be substituted with one or more substituents R¹, but are preferably unsubstituted. Preferred group R for X = NR are phenyl, biphenyl, terphenyl or fluorene, each of which can be partially or fully deuterated and/or substituted with one or more substituents R¹.

For X = CR2, the substituents R in the C atom are preferably, identically or differently at each instance, a straight-chain alkyl group having 1 to 10 C atoms, particularly preferably 1 , 2, 3, 4 or 5 C atoms, a branched or cyclic alkyl group having 3 to 10 C atoms, particularly preferably a branched alkyl group having 3, 4 or 5 C atoms or a cyclic alkyl group having 5 or 6 C atoms, or an aromatic ring system having 6 to 24 aromatic ring atoms, particularly preferably 6 to 18 aromatic ring atoms and very particularly preferred 6 to 12 aromatic ring atoms, where the aromatic ring system can be substituted with one or more radicals R¹, but is preferably unsubstituted; where each of these groups can be partially of fully deuterated; and/or where two radicals R may be connected to each other to form a ring. Particularly preferred groups R for X = CR2 are selected from methyl, phenyl, biphenyl or fluorenyl, each of which may be partially or fully deuterated.

A preferred embodiment of the formula (Ar¹-1) is therefore the structure of the following formula (Ar¹-1a),

X -0 t Formula (Ar¹-1a) wherein the dashed bond represents the bond to the nitrogen atom, X is selected from O or CR2 and the structure can be partially or fully deuterated. If X = O, the group of formula (Ar¹-1a) is preferably bound via the 1- or 4-position. If X = CR2, the group of formula (Ar¹-1a) is preferably bound the via the 1-, 2- or 4-position, particularly preferably via the 1- or 4-position.

Preferred groups Ar¹ and Ar² are the same or different at each instance and are selected from the following structures Ar-1 to Ar-287 in Table 1, each of which can be partially or fully deuterated and/or substituted with one or more substituents R. Particularly preferred structure are the groups of formulae Ar-1 , Ar-2, Ar-3-, Ar-4, Ar-5, Ar-16, Ar-17, Ar-48, Ar- 49, Ar-50, Ar-52, Ar-56, Ar-57, Ar-63, Ar-64, Ar-65, Ar-66, Ar-67, Ar-68, Ar-70, Ar-72, Ar- 74, Ar-78, Ar-82, Ar, 86, Ar-89, Ar-96, Ar-111 , Ar-112, Ar-114, Ar-117, Ar-139, Ar-140, Ar- 141 , Ar-142, Ar-143, Ar-144, Ar-157, Ar-173, Ar-174, Ar-207, Ar-208, Ar-211 , Ar-257, Ar- 260, Ar-262, Ar-263, Ar-264, Ar-171, Ar-172, Ar-279, Ar-285 and Ar-286, each of which can be partially or fully deuterated and/or substituted with one or more substituents R, but are preferably unsubstituted except for the explicitly depicted substituents.

Preferably, Ar³ is an aromatic ring system with 6 to 24 aromatic ring atoms, preferably with 6 to 18 aromatic ring atoms, particularly preferably with 6 to 12 aromatic ring atoms, each of which can be partially or fully deuterated and/or can be substituted by one or more substituents R, or a heteroaromatic ring system selected from dibenzofuran, dibenzothiophene or carbazole, each of which can be partially or fully deuterated and/or can be substituted by one or more substituents R. Preferred groups Ar³ are selected from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthyl, dibenzofuran, dibenzothiophene and carbazole, each of which can be partially or fully deuterated and/or substituted with one or more substituents R. If Ar³ is a heteroaromatic ring system, it is preferably dibenzofuran, which can be partially or fully deuterated.

Preferred groups Ar³ are selected from the structures Ar-1 to Ar-284 in Table 1, each of which can be partially or fully deuterated and/or substituted with one or more substituents R, and particularly preferred groups Ar³ are selected from the structures in Table 2, each of which can be partially or fully deuterated. Particularly preferably, Ar³ is a phenyl group, a biphenyl group, a fluorenyl group or a dibenzofuranyl group, each of which can be partially or fully deuterated. Most preferred, Ar³ is a phenyl group, which can be partially or fully deuterated, but does not comprise any substituents R. Preferably, the linking group L, if present, is a bivalent aromatic ring system having 6 to 18 aromatic ring atoms, more preferably 6 to 12 aromatic ring atoms, which can be substituted with one or more substituents R and/or which can be partially or fully deuterated. Preferred groups L are selected from ortho-, meta- or para-phenylene, ortho-, meta- or para-biphenyl, naphthylene or fluorenylene, each of which can be substituted with one or more substituents R and/or can be partially or fully deuterated. Particularly preferred groups L are selected from the following groups of formulae L-1 to L-82 in the following Table 3, wherein the most preferred groups L are selected from the groups L-1 to L-6, L-15, L-20, L-25, L-36, L-79 and L-81 :

Table 3

Preferably, the substituents R, if present, are, identically or differently at each instance, F, Si(R¹)a, a straight-chain alkyl or alkoxy group having 1 to 10 C atoms, a branched or cyclic alkyl or alkoxy group having 3 to 10 C atoms, wherein the alkyl or alkoxy group can be substituted by R¹, but is preferably unsubsituted, or an aromatic ring system having 6 to 24 aromatic ring atoms, where the aromatic ring system can be substituted with one or more radicals R¹, but is preferably unsubstituted; where each of these groups can be partially of fully deuterated; and/or where two adjacent radicals R may be connected to each other to form a ring. Particularly preferred, the substituents R, if present, are, identically or differently at each instance, selected from the group consisting of a straightchain alkyl group having 1, 2, 3, 4 or 5 C atoms, a branched alkyl group having 3, 4 or 5 C atoms or a cyclic alkyl group having 5 or 6 C atoms, or an aromatic ring system having 6 to 18 aromatic ring atoms and preferably 6 to 12 aromatic ring atoms, where the aromatic ring system can be substituted with one or more radicals R¹, but is preferably unsubstituted; where each of these groups can be partially of fully deuterated; and/or where two adjacent radicals R may be connected to each other to form a ring. Particularly preferred groups R, if present, are identically or differently at each instance, methyl or phenyl, each of which can be partially or fully deuterated.

If substituents R are present on the naphthyl group, these are preferably selected from an aromatic ring system having 6 to 24 aromatic ring atoms, particularly preferably 6 to 18 aromatic ring atoms and very particularly preferred 6 to 12 aromatic ring atoms, where the aromatic ring system can be substituted with one or more radicals R¹ and can be partially or fully deuterated. Preferred substituents R on the naphthyl group are selected from phenyl, ortho-, meta- or para-biphenyl, 1-naphthyl or 2-naphthyl where each of these groups can be substituted by one or more substituents R¹, but are preferably unsubstituted, and where each of these groups can be partially or fully deuterated. These substituents R are also preferred embodiments for the substituents R on the naphthyl group in the structures of formulae (2-2) to (2-7), (3-2) to (3-7), (2-2a) to (2-7a) and (3-2) to (3-7a).

Examples for preferred groups R are the substituents R-1 to R-195 in the following Table 4, wherein the groups R-1 , R-2, R-135, R-148, R-149, R-154, R-166, R-168, R-188, R-190 and R-193 are particularly preferred:

Table 4

Preferably, R¹, if present, is identically or differently at each instance an alkyl group having 1 to 10 C atoms, particularly preferably having 1 , 2, 3, 4 or 5 C atoms and most preferred methyl, each of which can be partially or fully deuterated.

It is particularly preferred that the preferred embodiments of the invention are combined with each other. Preferred are therefore the compounds of formulae (1), (2), (3), (2a), (3a), (2b), (3b), (2c), (3c), (2-1) to (2-7), (3-1) to (3-7), (2- 1a) to (2-7a) and (3- 1a) to (3-7a), which can be partially or fully deuterated and for which the following applies to the symbols and indices:

Ar¹, Ar² are the same or different at each instance and are an aromatic ring system with 6 to 24 aromatic ring atoms, each of which can be partially or fully deuterated and/or can be substituted by one or more substituents R, or a heteroaromatic ring system selected from dibenzofuran, dibenzothiophene, carbazole or benzofuran, each of which can be partially or fully deuterated and/or can be substituted by one or more substituents R;

Ar³ is an aromatic ring system with 6 to 24 aromatic ring atoms, which can be partially or fully deuterated and/or can be substituted by one or more substituents R, or a heteroaromatic ring system selected from dibenzofuran, dibenzothiophene or carbazole, each of which can be partially or fully deuterated and/or can be substituted by one or more substituents R;

L is a single bond or a bivalent aromatic ring system having 6 to 18 aromatic ring atoms, which can be substituted with one or more substituents R and/or which can be partially or fully deuterated;

R, if present, are, identically or differently at each instance, F, Si(R¹)a, a straight-chain alkyl or alkoxy group having 1 to 10 C atoms, a branched or cyclic alkyl or alkoxy group having 3 to 10 C atoms, wherein the alkyl or alkoxy group can be substituted by R¹, but is preferably unsubsituted, or an aromatic ring system having 6 to 24 aromatic ring atoms, where the aromatic ring system can be substituted with one or more radicals R¹, but is preferably unsubstituted; where each of these groups can be partially of fully deuterated; and/or where two adjacent radicals R may be connected to each other to form a ring; wherein substituent(s) R, if present on the naphthyl group, are selected from an aromatic ring system having 6 to 24 aromatic ring atoms, which can be substituted with one or more radicals R¹ and can be partially or fully deuterated;

R¹, if present, is identically or differently at each instance an alkyl group having 1 to 10 C atoms, which can be partially or fully deuterated. n is, identically or differently at each instance, 0, 1, 2 or 3, particularly preferably 0, 1 or 2, very particularly preferably 0 or 1 and most preferred 0; m is, identically or differently at each instance, 0, 1 or 2, particularly preferably 0 or 1 and most preferred 0; o is O or l ; p is 0, 1 or 2.

Very particularly preferred are therefore the compounds of formulae (1), (2), (3), (2a), (3a), (2b), (3b), (2c), (3c), (2-1) to (2-7), (3-1) to (3-7), (2-1a) to (2-7a) and (3-1a) to (3-7a), which can be partially or fully deuterated and for which the following applies to the symbols and indices:

Ar¹, Ar² are the same or different at each instance and are an aromatic ring system with 6 to 18 aromatic ring atoms, which can be partially or fully deuterated and/or can be substituted by one or more substituents R, or a heteroaromatic ring system selected from dibenzofuran, dibenzothiophene or carbazole, each of which can be partially or fully deuterated and/or can be substituted by one or more substituents R;

Ar³ is an aromatic ring system with 6 to 18 aromatic ring atoms, which can be partially or fully deuterated and/or can be substituted by one or more substituents R, or a heteroaromatic ring system selected from dibenzofuran, dibenzothiophene or carbazole, each of which can be partially or fully deuterated and/or can be substituted by one or more substituents R;

L is a single bond or a bivalent aromatic ring system having 6 to 12 aromatic ring atoms, which can be substituted with one or more substituents R and/or which can be partially or fully deuterated; R, if present, are, identically or differently at each instance, selected from the group consisting of a straight-chain alkyl group having 1 , 2, 3, 4 or 5 C atoms, a branched alkyl group having 3, 4 or 5 C atoms or a cyclic alkyl group having 5 or 6 C atoms, or an aromatic ring system having 6 to 18 aromatic ring atoms, where the aromatic ring system can be substituted with one or more radicals R¹, but is preferably unsubstituted; where each of these groups can be partially of fully deuterated; and/or where two adjacent radicals R may be connected to each other to form a ring; wherein substituent(s) R, if present on the naphthyl group, are selected from an aromatic ring system having 6 to 18 aromatic ring atoms, which can be substituted with one or more radicals R¹ and can be partially or fully deuterated;

R¹, if present, is identically or differently at each instance an alkyl group having 1 , 2, 3, 4 or 5 C atoms, which can be partially or fully deuterated; n is, identically or differently at each instance, 0, 1 or 2; m is, identically or differently at each instance, 0 or 1; o is = 0 or 1 , and p is 0 or 1 , o + p = 0 or 1.

Very particularly preferred are therefore the compounds of formulae (1), (2), (3), (2a), (3a), (2b), (3b), (2c), (3c), (2-1) to (2-7), (3-1) to (3-7), (2- 1a) to (2-7a) and (3- 1a) to (3-7a), which can be partially or fully deuterated and for which the following applies to the symbols and indices:

Ar¹, Ar² are the same or different at each instance and are an aromatic ring system with 6 to 12 aromatic ring atoms, each of which can be partially or fully deuterated and/or can be substituted by one or more substituents R, or a heteroaromatic ring system selected from dibenzofuran, dibenzothiophene, carbazole or benzofuran, each of which can be partially or fully deuterated and/or can be substituted by one or more substituents R;

Ar³ is an aromatic ring system with 6 to 12 aromatic ring atoms, each of which can be partially or fully deuterated and/or can be substituted by one or more substituents R, or a heteroaromatic ring system selected from dibenzofuran, dibenzothiophene or carbazole, each of which can be partially or fully deuterated and/or can be substituted by one or more substituents R;

L is a single bond or a bivalent aromatic ring system selected from ortho-, meta- or para-phenylene, ortho-, meta- or para-biphenyl, naphthylene or fluorenylene, each of which can be substituted with one or more substituents R and/or can be partially or fully deuterated;

R, if present, are, identically or differently at each instance, selected from the group consisting of a straight-chain alkyl group having 1 , 2, 3, 4 or 5 C atoms, a branched alkyl group having 3, 4 or 5 C atoms or a cyclic alkyl group having 5 or 6 C atoms, or an aromatic ring system having 6 to 12 aromatic ring atoms, where the aromatic ring system can be substituted with one or more radicals R¹; where each of these groups can be partially of fully deuterated; and/or where two adjacent radicals R may be connected to each other to form a ring; wherein R, if present on the naphthyl group, these are preferably selected from an aromatic ring system having 6 to 12 aromatic ring atoms, where the aromatic ring system can be substituted with one or more radicals R¹ and can be partially or fully deuterated;

R¹, if present, is identically or differently at each instance an alkyl group having 1 , 2, 3, 4 or 5 C atoms, which can be partially or fully deuterated; n is, identically or differently at each instance, 0 or 1 ; m is, identically or differently at each instance, 0 or 1 and most preferred 0; o is = 0 or 1 , and p is 0 or 1 , and o + p = 0 or 1 .

Most preferred are the compounds of formulae (1), (2), (3), (2a), (3a), (2b), (3b), (2c), (3c), (2-1) to (2-7), (3-1) to (3-7), (2-1a) to (2-7a) and (3-1a) to (3-7a), which can be partially or fully deuterated and for which the following applies to the symbols and indices:

Ar¹, Ar² are the same or different at each instance and are independently selected from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthyl, dibenzofuran, dibenzothiophene and carbazole, each of which can be partially or fully deuterated and/or substituted with one or more groups R; Ar³ is selected from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthyl, dibenzofuran, dibenzothiophene and carbazole, each of which can be partially or fully deuterated and/or substituted with one or more substituents R, wherein Ar³ is most preferably a phenyl group, which can be partially or fully deuterated;

R, if present, are, identically or differently at each instance, selected from the group consisting of a straight-chain alkyl group having 1 , 2, 3, 4 or 5 C atoms, a branched alkyl group having 3, 4 or 5 C atoms or a cyclic alkyl group having 5 or 6 C atoms, or an aromatic ring system having 6 to 12 aromatic ring atoms, where the aromatic ring system can be substituted with one or more radicals R¹; where each of these groups can be partially of fully deuterated; and/or where two adjacent radicals R may be connected to each other to form a ring; wherein R, if present on the naphthyl group, are selected from phenyl, ortho-, meta- or para-biphenyl, 1-naphthyl or 2-naphthyl where each of these groups can be substituted by one or more substituents R¹, but are preferably unsubstituted, and where each of these groups can be partially or fully deuterated;

R¹, if present, is identically or differently at each instance an alkyl group having 1 , 2, 3, 4 or 5 C atoms, which can be partially or fully deuterated; n is, identically or differently at each instance, 0, 1, 2 or 3, particularly preferably 0, 1 or 2, very particularly preferably 0 or 1 and most preferred 0; m is, identically or differently at each instance, 0, 1 or 2, particularly preferably 0 or 1 and most preferred 0; o is = 0 or 1 and p is 0, 1 or 2, preferably p = 0 or 1. Furthermore, in a preferred embodiment, o + p = 0 or 1. Particularly preferred, o = 0 and p = 0. As described above, the inventive compounds can be partially or fully deuterated. If the compound is deuterated, a degree of deuteration of at least 20 % is preferred. The term “deuterated” has the meaning that in such a compound the corresponding portion of the H atoms of the undeuterated compound are exchanged for D (deuterium). The undeuterated compound is the corresponding compound, which contains hydrogen in the natural isotope distribution. The degree of deuteration relates to mol% and designates the average degree of deuteration of the compound, i.e. the average fraction of the H atoms in the compound which are replaced by D atoms. In a fully deuterated compound, all H atoms are replaced by D, and the degree of deuteration is 100 %. A degree of deuteration of at least 20 % has the meaning that in average 20 to 100 % of the H atoms in the compound are replaced by D atoms. In a preferred embodiment of the invention, the degree of deuteration at least 30 %, more preferred at least 40 %, particularly preferred at least 50 % and very particularly preferred at least 50 %. In general, a high degree of deuteration is desirable. This, however, can be achieved only with a very high synthetic effort. Even though a degree of deuteration of 100 % would therefore be desirable, an upper limit if the degree of deuteration of 95 %, 90% or 85 % is still acceptable. As the indication of the degree of deuteration relates to the average of a mixture of differently deuterated compounds, such a mixture comprises compounds of the same backbone, wherein the single compounds differ in the position and degree of deuteration.

Preferred specific compounds according to formula (1) are the following ones wherein D0- Dx indicates the degree of deuteration: The compounds according to formula (1) may be prepared by synthesis methods such as Buchwald coupling and Suzuki coupling. The skilled person is aware of several possible synthetic routes, based on his general knowledge of organic synthetic chemistry. A suitable synthetic route to prepare compounds according to formula (1) is described in the following: For preparation of the compound according to formula (1), 9-aryl-9-phenyl- fluorene derivative which is substituted in the 3- and 5-position of the phenyl group with two different reactive leaving groups is first reacted with a group naphthyl group, which bears a boronic acid or boronic ester leaving group in a Suzuki coupling reaction. The reaction takes place on the position bearing the more reactive of the two leaving groups in 3, 5-position of the phenyl group. The resulting intermediate is then reacted on the position of the phenyl group bearing the less reactive leaving group with a secondary amine bearing a group Ar¹ and a group Ar² in a Hartwig-Buchwald coupling reaction to result in a compound of formula (1). Alternatively, if a linking group L is present between the phenyl group and the nitrogen atom, the group -L-NAr¹Ar² can be introduced in a second Suzuki coupling reaction with a compound L-NAr¹Ar² which is substituted on L with a reactive group, in particular a boronic acid or boronic ester. Further reactions, such as deuteration of the compound, may follow. Suitable reactive leaving groups in 3, 5-position of the phenyl group are chloride, bromide, iodide, tosylate and triflate. The reactants described are in many cases commercially available. Specific starting materials and reactants needed to obtain specific compounds according to formula (1) that are not available commercially, can be prepared using methods known to the skilled person. The synthesis is illustrated in the following Scheme 1 .

Scheme 1

where L¹ and L² represent leaving groups and are preferably different from each other, Y is a leaving group which is capable of coupling with L¹, and the other symbols and indices have the same meanings as defined above. In a preferable embodiment, L¹ and L² are two different groups selected from chloride, bromide, iodide, tosylate and triflate, where chloride and bromide are preferred, and Y is boronic acid or a boronic ester.

Object of the present patent application is therefore a process for preparation of a compound according to formula (1) and the preferred embodiments, characterised by the following reaction steps:

(a) reacting a 9-aryl-9-phenyl-fluorene derivative, which is substituted in the 3- and 5- position of the phenyl group with two different reactive leaving groups with a naphthalene, which bears a boronic acid or boronic ester as a leaving group in a Suzuki coupling reaction; and

(b) reaction the intermediate obtained in step (a) with a secondary amine bearing a group Ar¹ and a group Ar² in a Hartwig-Buchwald coupling reaction or reaction of the intermediate obtained in step (a) with a triarylamine bearing the groups Ar¹, Ar² and L, wherein L is substituted with a boronic acid or boronic ester as leaving group in a Suzuki coupling reaction. For the processing of the compounds of the invention from a liquid phase, for example by spin-coating or by printing methods, formulations of the compounds of the invention are required. These formulations may, for example, be solutions, dispersions or emulsions. For this purpose, it may be preferable to use mixtures of two or more solvents. Suitable solvents are generally known to the skilled person. The invention therefore further provides a formulation, especially a solution, dispersion or emulsion, comprising at least one compound of formula (1) and at least one solvent, preferably an organic solvent. The way in which such solutions can be prepared is known to those skilled in the art.

The compound of formula (1) and the preferred embodiments is suitable for use in an electronic device, especially an organic electroluminescent device (OLED). Depending on the substitution, the compound of the formula (1) and the preferred embodiments can be used in different functions and layers. Preference is given to use as a hole-transporting material in a hole-transporting layer and/or as matrix material in an emitting layer, more preferably in combination with a phosphorescent emitter.

The invention therefore further provides for the use of a compound of formula (1) and the preferred embodiments in an electronic device. This electronic device is preferably selected from the group consisting of organic integrated circuits (OlCs), organic fieldeffect transistors (OFETs), organic thin-film transistors (OTFTs), organic light-emitting transistors (OLETs), organic solar cells (OSCs), organic optical detectors, organic photoreceptors, organic field-quench devices (OFQDs), organic light-emitting electrochemical cells (OLECs), organic laser diodes (O-lasers) and more preferably organic electroluminescent devices (OLEDs).

The invention further provides an electronic device comprising at least one compound of formula (1) or the preferred embodiments. This electronic device is preferably selected from the above-mentioned devices.

Particular preference is given to an organic electroluminescent device comprising anode, cathode and at least one emitting layer, characterized in that at least one organic layer comprising at least one compound of formula (1) or the preferred embodiments is present in the device. Preference is given to an organic electroluminescent device comprising anode, cathode and at least one emitting layer, characterized in that at least one organic layer in the device, selected from hole-transporting and emitting layers, preferably selected from hole-transporting layers, comprises at least one compound of formula (1) or the preferred embodiments. A hole-transporting layer is understood here to mean all layers disposed between anode and emitting layer, preferably hole injection layer, hole transport layer and electron blocking layer. A hole injection layer is understood here to mean a layer that directly adjoins the anode. A hole transport layer is understood here to mean a layer which is between the anode and emitting layer but does not directly adjoin the anode, and preferably does not directly adjoin the emitting layer either. An electron blocking layer is understood here to mean a layer which is between the anode and emitting layer and directly adjoins the emitting layer. An electron blocking layer preferably has a high-energy LIIMO and hence prevents electrons from exiting from the emitting layer.

Apart from the cathode, anode and emitting layer, the electronic device may comprise further layers. These are selected, for example, from in each case one or more hole injection layers, hole transport layers, hole blocking layers, electron transport layers, electron injection layers, electron blocking layers, exciton blocking layers, interlayers, charge generation layers and/or organic or inorganic p/n junctions. However, it should be pointed out that not every one of these layers need necessarily be present and the choice of layers always depends on the compounds used and especially also on whether the device is a fluorescent or phosphorescent electroluminescent device.

The sequence of layers in the electronic device is preferably as follows:

- anode

- hole injection layer

- hole transport layer

- optionally further hole transport layers

- optionally electron blocking layer

- emitting layer

- optionally hole blocking layer

- electron transport layer

- electron injection layer

- cathode.

At the same time, it should be pointed out again that not all the layers mentioned need be present and/or that further layers may additionally be present.

The organic electroluminescent device of the invention may contain two or more emitting layers. More preferably, these emission layers have several emission maxima between 380 nm and 750 nm overall, such that the overall result is white emission; in other words, various emitting compounds which may fluoresce or phosphoresce and which emit blue, green, yellow, orange or red light are used in the emitting layers. Especially preferred are three-layer systems, i.e. systems having three emitting layers, wherein one of the three layers in each case shows blue emission, one of the three layers in each case shows green emission, and one of the three layers in each case shows orange or red emission. The compounds of the invention here are preferably present in a hole-transporting layer or in the emitting layer. It should be noted that, for the production of white light, rather than a plurality of colour-emitting emitter compounds, an emitter compound used individually which emits over a broad wavelength range may also be suitable.

It is preferable that the compound of the formula (1) or the preferred embodiments is used as hole transport material. The emitting layer here may be a fluorescent emitting layer, or it may be a phosphorescent emitting layer. The emitting layer is preferably a bluefluorescing layer or a green-phosphorescing layer.

When the device containing the compound of the formula (1) or the preferred embodiments contains a phosphorescent emitting layer, it is preferable that this layer contains two or more, preferably exactly two, different matrix materials (mixed matrix system). Preferred embodiments of mixed matrix systems are described in detail further down.

If the compound of formula (1) or the preferred embodiments is used as hole transport material in a hole transport layer, a hole injection layer or an electron blocking layer, the compound can be used as pure material, i.e. in a proportion of 100%, in the hole transport layer, or it can be used in combination with one or more further compounds.

In a preferred embodiment, a hole-transporting layer comprising the compound of the formula (1) or the preferred embodiments additionally comprises one or more further holetransporting compounds. These further hole-transporting compounds are preferably selected from triarylamine compounds, more preferably from monotriarylamine compounds. They are most preferably selected from the preferred embodiments of hole transport materials that are specified further down. In the preferred embodiment described, the compound of the formula (1) or the preferred embodiments and the one or more further hole-transporting compounds are preferably each present in a proportion of at least 10%, more preferably each in a proportion of at least 20%. In a preferred embodiment, a hole-transporting layer comprising the compound of the formula (1) or the preferred embodiments additionally contains one or more p-dopants. p- Dopants used according to the present invention are preferably those organic electron acceptor compounds capable of oxidizing one or more of the other compounds in the mixture.

Particularly preferred as p-dopants are quinodimethane compounds, azaindenofluorene- diones, azaphenalenes, azatriphenylenes, I2, metal halides, preferably transition metal halides, metal oxides, preferably metal oxides comprising at least one transition metal or a metal from main group 3, and transition metal complexes, preferably complexes of Cu, Co, Ni, Pd and Pt with ligands containing at least one oxygen atom as binding site. Preference is further given to transition metal oxides as dopants, preferably oxides of rhenium, molybdenum and tungsten, more preferably Re2O?, MoOa, WO3 and ReCh. Still further preference is given to complexes of bismuth in the (III) oxidation state, more particularly bismuth(lll) complexes with electron-deficient ligands, more particularly carboxylate ligands. Preferred p-dopants are furthermore the compounds which are explicitly disclosed in the table on p. 86-87 of WO 2021/156323A1.

The p-dopants are preferably in substantially homogeneous distribution in the p-doped layers. This can be achieved, for example, by co-evaporation of the p-dopant and the hole transport material matrix. The p-dopant is preferably present in a proportion of 1 % to 10% in the p-doped layer.

In a preferred embodiment, a hole injection layer that conforms to one of the following embodiments is present in the device: a) it contains a triarylamine and a p-dopant; or b) it contains a single electron-deficient material (electron acceptor). In a preferred embodiment of embodiment a), the triarylamine is a monotriarylamine, especially one of the preferred triarylamine derivatives mentioned further down. In a preferred embodiment of embodiment b), the electron-deficient material is a hexaazatriphenylene derivative as described in US 2007/0092755.

The compound of the formula (1) or the preferred embodiments may be present in a hole injection layer, in a hole transport layer and/or in an electron blocking layer of the device. When the compound is present in a hole injection layer or in a hole transport layer, it has preferably been p-doped, meaning that it is in mixed form with a p-dopant, as described above, in the layer. The compound of the formula (1) or the preferred embodiments is preferably present in an electron blocking layer. In this case, it is preferably not p-doped. Further preferably, in this case, it is preferably in the form of a single compound in the layer without addition of a further compound.

In an alternative preferred embodiment, the compound of the formula (1) or the preferred embodiments is used in an emitting layer as matrix material in combination with one or more emitting compounds, preferably phosphorescent emitting compounds. The phosphorescent emitting compounds here are preferably selected from red- phosphorescing and green-phosphorescing compounds.

The proportion of the matrix material in the emitting layer in this case is between 50.0% and 99.9% by volume, preferably between 80.0% and 99.5% by volume, and more preferably between 85.0% and 97.0% by volume.

Correspondingly, the proportion of the emitting compound is between 0.1% and 50.0% by volume, preferably between 0.5% and 20.0% by volume, and more preferably between 3.0% and 15.0% by volume.

An emitting layer of an organic electroluminescent device may also contain systems comprising a plurality of matrix materials (mixed matrix systems) and/or a plurality of emitting compounds. In this case too, the emitting compounds are generally those compounds having the smaller proportion in the system and the matrix materials are those compounds having the greater proportion in the system. In individual cases, however, the proportion of a single matrix material in the system may be less than the proportion of a single emitting compound.

It is preferable that the compounds of formula (1) or the preferred embodiments are used as a component of mixed matrix systems, preferably for phosphorescent emitters. The mixed matrix systems preferably comprise two or three different matrix materials, more preferably two different matrix materials. Preferably, in this case, one of the two materials is a material having hole-transporting properties and the other material is a material having electron-transporting properties. It is further preferable when one of the materials is selected from compounds having a large energy differential between HOMO and LIIMO (wide-bandgap materials). The compound of the formula (1) in a mixed matrix system is preferably the matrix material having hole-transporting properties. Correspondingly, when the compound of the formula (1) is used as matrix material for a phosphorescent emitter in the emitting layer of an OLED, a second matrix compound having electron-transporting properties is present in the emitting layer. The two different matrix materials may be present here in a ratio of 1 :50 to 1 : 1 , preferably 1 :20 to 1 : 1 , more preferably 1 : 10 to 1 : 1 and most preferably 1:4 to 1:1.

The desired electron-transporting and hole-transporting properties of the mixed matrix components may, however, also be combined mainly or entirely in a single mixed matrix component, in which case the further mixed matrix component(s) fulfil(s) other functions.

Preference is given to using the following material classes in the above-mentioned layers of the device:

Phosphorescent emitters: The term "phosphorescent emitters" typically encompasses compounds where the emission of light is effected through a spin-forbidden transition, for example a transition from an excited triplet state or a state having a higher spin quantum number, for example a quintet state. Suitable phosphorescent emitters are especially compounds which, when suitably excited, emit light, preferably in the visible region, and also contain at least one atom of atomic number greater than 20, preferably greater than 38, and less than 84, more preferably greater than 56 and less than 80. Preference is given to using, as phosphorescent emitters, compounds containing copper, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, iridium, palladium, platinum, silver, gold or europium, especially compounds containing iridium, platinum or copper. In the context of the present invention, all luminescent iridium, platinum or copper complexes are considered to be phosphorescent compounds.

In general, all phosphorescent complexes as used for phosphorescent OLEDs according to the prior art and as known to those skilled in the art in the field of organic electroluminescent devices are suitable for use in the devices of the invention. Further examples of suitable phosphorescent emitters are those shown in the table on p.100-104 of WO 2023/025971A2.

Fluorescent emitters: Preferred fluorescent emitting compounds are selected from the class of the arylamines. An arylamine or an aromatic amine in the context of this invention is understood to mean a compound containing three substituted or unsubstituted aromatic or heteroaromatic ring systems bonded directly to the nitrogen. Preferably, at least one of these aromatic or heteroaromatic ring systems is a fused ring system, more preferably having at least 14 aromatic ring atoms. Preferred examples of these are aromatic anthraceneamines, aromatic anthracenediamines, aromatic pyreneamines, aromatic pyrenediamines, aromatic chryseneamines or aromatic chrysenediamines. An aromatic anthraceneamine is understood to mean a compound in which a diarylamino group is bonded directly to an anthracene group, preferably in the 9 position. An aromatic anthracenediamine is understood to mean a compound in which two diarylamino groups are bonded directly to an anthracene group, preferably in the 9,10 position. Aromatic pyreneamines, pyrenediamines, chryseneamines and chrysenediamines are defined analogously, where the diarylamino groups are bonded to the pyrene preferably in the 1 position or 1,6 position. Further preferred emitting compounds are indenofluoreneamines or -diamines, benzoindenofluoreneamines or -diamines, and dibenzoindenofluorene- amines or -diamines, and indenofluorene derivatives having fused aryl groups. Likewise preferred are pyrenearylamines. Likewise preferred are benzoindenofluoreneamines, benzofluoreneamines, extended benzoindenofluorenes, phenoxazines, and fluorene derivatives joined to furan units or to thiophene units. Furhter preferred fluorescent emitters are DABNA and derivatives of DABNA.

Matrix materials for fluorescent emitters: Preferred matrix materials for fluorescent emitters are selected from the classes of the oligoarylenes (e.g. 2,2’,7,7’-tetraphenyl- spirobifluorene), especially the oligoarylenes containing fused aromatic groups, the oligoarylenevinylenes, the polypodal metal complexes, the hole-conducting compounds, the electron-conducting compounds, especially ketones, phosphine oxides and sulfoxides; the atropisomers, the boronic acid derivatives or the benzanthracenes. Particularly preferred matrix materials are selected from the classes of the oligoarylenes comprising naphthalene, anthracene, benzanthracene and/or pyrene or atropisomers of these compounds, the oligoarylenevinylenes, the ketones, the phosphine oxides and the sulfoxides. Very particularly preferred matrix materials are selected from the classes of the oligoarylenes comprising anthracene, benzanthracene, benzophenanthrene and/or pyrene or atropisomers of these compounds. An oligoarylene in the context of this invention shall be understood to mean a compound in which at least three aryl or arylene groups are bonded to one another.

Matrix materials for phosphorescent emitters: Preferred matrix materials for phosphorescent emitters are, as well as the compounds of the formula (1), aromatic ketones, aromatic phosphine oxides or aromatic sulfoxides or sulfones, triarylamines, carbazole derivatives, e.g. CBP (N,N-biscarbazolylbiphenyl) or carbazole derivatives, indolocarbazole derivatives, indenocarbazole derivatives, azacarbazole derivatives, bipolar matrix materials, silanes, azaboroles or boronic esters, triazine derivatives, zinc complexes, diazasilole or tetraazasilole derivatives, diazaphosphole derivatives, bridged carbazole derivatives, triphenylene derivatives, or lactams.

Electron-transporting materials: Suitable electron-transporting materials are, for example, the compounds disclosed in Y. Shirota et al., Chem. Rev. 2007, 107(4), 953-1010, or other materials used in these layers according to the prior art. Materials used for the electron transport layer may be any materials that are used as electron transport materials in the electron transport layer according to the prior art. Especially suitable are aluminium complexes, for example Alqa, zirconium complexes, for example Zrq4, lithium complexes, for example Liq, benzimidazole derivatives, triazine derivatives, pyrimidine derivatives, pyridine derivatives, pyrazine derivatives, quinoxaline derivatives, quinoline derivatives, oxadiazole derivatives, aromatic ketones, lactams, boranes, diazaphosphole derivatives and phosphine oxide derivatives. Preferred electron transport and electron injection materials are those shown in the table on p. 73-75 of WO 2020/109434 A1.

Hole-transporting materials: Further compounds which, in addition to the compounds of the formula (1), are preferably used in hole-transporting layers of the OLEDs of the invention are indenofluoreneamine derivatives, amine derivatives, hexaazatriphenylene derivatives, amine derivatives with fused aromatic systems, monobenzoindenofluorene- amines, dibenzoindenofluoreneamines, spirobifluoreneamines, fluoreneamines, spirodibenzopyranamines, dihydroacridine derivatives, spirodibenzofurans and spirodibenzothiophenes, phenanthrenediarylamines, spirotribenzotropolones, spirobifluorenes having meta-phenyldiamine groups, spirobisacridines, xanthenediarylamines, and 9,10-dihydro- anthracene spiro compounds having diarylamino groups. Preferred hole-transporting compounds are those shown the table on p. 76-80 of WO 2020/109434 A1.

Preferred cathodes of the electronic device are metals having a low work function, metal alloys or multilayer structures composed of various metals, for example alkaline earth metals, alkali metals, main group metals or lanthanoids (e.g. Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.). Additionally suitable are alloys composed of an alkali metal or alkaline earth metal and silver, for example an alloy composed of magnesium and silver. In the case of multilayer structures, in addition to the metals mentioned, it is also possible to use further metals having a relatively high work function, for example Ag or Al, in which case combinations of the metals such as Ca/Ag, Mg/Ag or Ba/Ag, for example, are generally used. It may also be preferable to introduce a thin interlayer of a material having a high dielectric constant between a metallic cathode and the organic semiconductor. Examples of useful materials for this purpose are alkali metal or alkaline earth metal fluorides, but also the corresponding oxides or carbonates (e.g. LiF, U2O, BaF2, MgO, NaF, CsF, CS2CO3, etc.). It is also possible to use lithium quinolinate (LiQ) for this purpose. The layer thickness of this layer is preferably between 0.5 and 5 nm.

Preferred anodes are materials having a high work function. Preferably, the anode has a work function of greater than 4.5 eV versus vacuum. Firstly, metals having a high redox potential are suitable for this purpose, for example Ag, Pt or Au. Secondly, metal/metal oxide electrodes (e.g. Al/N i/N iO_x, AI/PtO_x) may also be preferred. For some applications, at least one of the electrodes has to be transparent or partly transparent in order to enable either the irradiation of the organic material (organic solar cell) or the emission of light (OLED, O-LASER). Preferred anode materials here are conductive mixed metal oxides. Particular preference is given to indium tin oxide (ITO) or indium zinc oxide (IZO). Preference is further given to conductive doped organic materials, especially conductive doped polymers. In addition, the anode may also consist of two or more layers, for example of an inner layer of ITO and an outer layer of a metal oxide, preferably tungsten oxide, molybdenum oxide or vanadium oxide.

In a preferred embodiment, the electronic device is characterized in that one or more layers are coated by a sublimation process. In this case, the materials are applied by vapour deposition in vacuum sublimation systems at an initial pressure of less than 10^-5 mbar, preferably less than 10'⁶ mbar. In this case, however, it is also possible that the initial pressure is even lower, for example less than 10'⁷ mbar.

Preference is likewise given to an electronic device, characterized in that one or more layers are coated by the OVPD (organic vapour phase deposition) method or with the aid of a carrier gas sublimation. In this case, the materials are applied at a pressure between 10'⁵ mbar and 1 bar. A special case of this method is the OVJP (organic vapour jet printing) method, in which the materials are applied directly by a nozzle and thus structured (for example M. S. Arnold et al., Appl. Phys. Lett. 2008, 92, 053301).

Preference is additionally given to an electronic device, characterized in that one or more layers are produced from solution, for example by spin-coating, or by any printing method, for example screen printing, flexographic printing, nozzle printing or offset printing, but more preferably LITI (light-induced thermal imaging, thermal transfer printing) or inkjet printing. For this purpose, soluble compounds of formula (1) are needed. High solubility can be achieved by suitable substitution of the compounds. It is further preferable that an electronic device of the invention is produced by applying one or more layers from solution and one or more layers by a sublimation method.

After application of the layers, according to the use, the device is structured, contact- connected and finally sealed, in order to rule out damaging effects of water and air.

According to the invention, the electronic devices comprising one or more compounds of formula (1) or the preferred embodiments can be used in displays or as light sources in lighting applications.

The compounds of the present invention have the following advantages:

(1) The inventive compounds have an improved glass transition temperature.

(2) The inventive compounds have an improved thermal stability which is shown by a higher decomposition temperature.

(3) The inventive compounds when used in a hole-transporting layer of an OLED result in very good device properties with respect to efficiency, lifetime and operating voltage, in particular efficiency (EQE) and lifetime.

(4) The inventive compounds when used in a hole-transporting layer of an OLED result in a low lateral current (little crosstalk) and specifically in a good capacitance.

The invention is now illustrated in detail by the examples which follow, without any intention of restricting it thereby.

Examples

Synthesis of lnt-1

In a 1-L 3-necked round bottom flask magnesium turnings (7.50 g, 309 mmol, 1.15 eq.) are dried under N2. After cooling to RT, anhydrous Et20 (240 mL) and 1,2-dibromoethane (5 drops) are added. The mixture is slightly heated to 35 °C. A solution of 2-bromobiphenyl (50.9 mL, 295 mmol, 1.1 eq) in anhydrous Et20 (240 mL) is charged in an addition funnel and approx. 3 mL of the solution is added to the reaction at 35 °C. The rest of the 2- bromobiphenyl solution is added dropwise into the reaction over 1 h. Once the addition is complete, the mixture is stirred at reflux temperature for 30 min. In a second 2L 3-necked round bottom flask is prepared a solution of (3-bromo-5-chlorophenyl)(phenyl)methanone (79.3 g, 268 mmol) in anhydrous Et20 (240 mL). At 35 °C, the solution of biphenyl magnesium bromide is slowly added to the solution of (3-bromo-5-chlorophenyl)(phenyl)- methanone over 30 min. The reaction mixture is stirred at reflux temperature for 1 h. The reaction mixture is cooled to 0-5°C with an ice bath and the reaction is quenched with sat. NH4CI (400 mL).The layers are separated and the aqueous layer is extracted with EtOAc (2 x 300 mL). The combined organic layers are washed with 5% NaCI (300 mL), dried over MgSCL and evaporated under reduced pressure to provide the crude product, which is further purified by crystallisation out of heptane. Yield: 91.7 g, (203 mmol, 76% )

Synthesis of lnt-2

91.7 g (204 mmol) of lnt-1 are dissolved in DCM (900 mL) under N2. The mixture is cooled to 0 °C with an ice/water bath and TfOH (36.2 mL, 408 mmol, 2 eq) is added dropwise over 15 min and stirred at room temperature for 1 h. The solution is quenched with H2O (450 mL) and 270 mL sat. NaHCCh is added over 10 min and the mixture is stirred for 30 min. The aqueous layer is extracted with DCM (2 x 270 mL). The combined organic layers are washed with sat. NaHCCh (270 mL) and 5%. NaCI (270 mL), dried over MgSCL and evaporated under reduced pressure to provide the crude product, which is further purified by refluxing in heptane. After cooling down to 0 °C, the product is filtered off and washed with cold heptane to provide lnt-2 as a off-white solid. Yield: 81.9 g, (190 mmol, 93%)

Synthesis of lnt-3a

30.0 g (68.9 mmol) lnt-2, 12.4 g (72.3 mmol) 2-naphthyl-boronic acid (SM-1) and 21.9 g (206.7 mmol) sodium carbonate are dissolved in 450 mL THF/water/ethanol (5:3:1). 322.4 mg (0.46 mmol) bis(triphenylphosphine)palladium(ll) dichloride are added, and the mixture is refluxed for 16 hours until full conversion. After cooling down to room temperature the reaction mixture is filtered through celite, and the phases are separated. The organic phase is evaporated under reduced pressure to provide the crude product, which is further purified by filtration over silica and stirring in heptane. Yield: 22.0 g (45.9 mmol, 67%)

The following compounds can be synthesised in analogous manner:

Synthesis of compound 1

15.0 g (31.3 mmol) lnt-3b, 12.87 g (31.3 mmol) 955959-89-4 and 12.92 g (46.9 mmol) sodium-tert-pentoxide are dissolved in 165 mL toluene. 289.3 mg (0.312 mmol) Pd2(dba)s and 393.0 mg (0.938 mmol) SPhos are added, and the mixture is stirred at 90 °C overnight. After full conversion the reaction mixture is allowed to come to room temperature. The precipitate is filtered off. The product is further purified by filtration over aluminum oxide and crystallisation out of toluene until a HPLC purity of >99.9%, and the remaining solvents are removed by sublimation (350 °C at 10'⁶ bar). Yield: 21.8 g (25.5 mmol, 81%)

The following compounds can be synthesized in analogous manner:

Synthesis of compound L1

15.0 g (31.3 mmol) lnt-3b, 16.2 g (31.3 mmol) 952431-30-0 and 14.37 (62 mmol) potassium phosphate are mixed in 700 ml THF/water (2:1). 660 mg (0.8 mmol) X-Phos Pd G3 are added and the reaction mixture is stirred at 60 °C for 18 hours. After full conversion the reaction mixture is allowed to come to room temperature. 200 ml brine are added and the phases are separated. The aqueous phase is extracted with THF and the combined organic phases are extracted with brine and dried over magnesium sulfate. The solvent is removed by reduced pressure and the crude is purified by filtration over aluminum oxide (toluene) and crystallisation out of toluene until a HPLC purity of >99.9%, and the remaining solvents are removed by sublimation (350 °C at 10'⁶ bar). Yield: 17.8 g (21.2 mmol, 67%)

B) Device examples

1) General production process for the OLEDs and characterization of the OLEDs Glass plaques which have been coated with structured ITO (indium tin oxide) in a thickness of 50 nm are the substrates to which the OLEDs are applied. The OLEDs basically have the following layer structure: substrate / hole injection layer (HIL) / hole transport layer (HTL) / electron blocker layer (EBL) / emission layer (EML) / electron transport layer, optionally with second layer (ETL) / electron injection layer (EIL) and finally a cathode. The cathode is formed by an aluminium layer of thickness 100 nm. The exact structure of the OLEDs can be found in the tables which follow. The materials used for production of the OLEDs are shown in a table below. All materials are applied by thermal vapour deposition in a vacuum chamber. In this case, the emission layer consists of at least one matrix material (host material) and an emitting dopant which is added to the matrix material(s) in a particular proportion by volume by co-evaporation. Details given in such a form as TMM-1 (32%):TMM-2 (60%):TEG(8%) mean here that the material TMM-1 is present in the layer in a proportion by volume of 32%, TMM-2 is present in the layer in a proportion by volume of 60% and TEG in a proportion by volume of 8%. In an analogous manner, the electron transport layer and the hole injection layer also consist of a mixture of two materials. The structures of the materials that are used in the OLEDs are shown in Table 3.

The OLEDs are characterized in a standard manner. For this purpose, the electroluminescence spectra, the external quantum efficiency (EQE, measured in %) as a function of the luminance, calculated from current-voltage-luminance characteristics assuming Lambertian radiation characteristics, and the lifetime are determined. The parameter EQE @ 10 mA/cm² refers to the external quantum efficiency which is attained at 10 mA/cm². The parameter U @ 10 mA/cm² refers to the operating voltage at 10 mA/cm². The lifetime LT is defined as the time after which the luminance drops from the starting luminance to a certain proportion in the course of operation with constant current density. An LT90 figure means here that the lifetime reported corresponds to the time after which the luminance has dropped to 90% of its starting value. The figure @80 mA/cm² means here that the lifetime in question is measured at 80 mA/cm².

Devices as shown in the following table are produced:

Table 2: Structure of the OLEDs

In the device setup shown above, the OLED with the compounds, HT-A, HT-B, HT-C, HT- D and HT-E of the invention give good voltages and efficiencies while showing a superior lifetime over the comparison examples C1 and C2:

Furthermore, the inventive compounds according to the claims are particularly suitable as 2nd EBL for OLEDs comprising more than one EBL. The inventive compounds show outstanding lifetimes and low capacitance in OLEDs comprising more than one EBL and a phosphorescent EML.

Claims

Patent Claims

1. Compound of formula (1),

L is an aromatic ring system having 6 to 24 aromatic ring atoms which can be substituted with one or more R radicals and which can be partially or fully deuterated;

R is, identically or differently at each instance, F, Cl, Br, I, CN, Si(R¹)a, a straightchain alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms or a branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 20 C atoms wherein the alkyl, alkoxy or thioalkyl group can be substituted with one or more radicals R¹, an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms which can be substituted with one or more radicals R¹ or an aryloxy or heteroaryloxy group which can be substituted with one or more radicals R¹ or a combination of these systems; where all of these groups can be partially or fully deuterated; where two or more adjacent radicals R may be connected to each other to form a ring; R¹ is, identically or differently at each instance, F, an alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms where one ore more H atoms of the alkyl, alkoxy or thioalkyl group can be replaced by F, or an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms; where all of these groups can be partially or fully deuterated; where two or more adjacent radicals R¹ may be connected to each other to form a ring; n is, identically or differently at each instance, 0, 1 , 2, 3 or 4; m is, identically or differently at each instance, 0, 1 , 2 or 3; o is 0, 1 , 2 or 3; p is 0, 1 , 2, 3 or 4; q is O or l .

2. Compound according to claim 1 , characterised in that the compound is selected from the compounds of formula (2) and (3),

Formula (2) Formula (3) wherein the symbols and indices have the same meanings as defined in claim 1 and the compounds can be partially or fully deuterated.

3. Compound according to claim 1 or 2, characterised in that the indices n are, identically or differently at each instance, 0, 1, 2 or 3, preferably 0, 1 or 2, and particularly preferably 0 or 1, and that the indices m are, identically or differently at each instance, 0, 1 or 2 and preferably 0 or 1.

4. Compound according to one or more of claims 1 to 3, characterised in that the compound is selected from the compounds of formula (2a) and (3a),

Formula (2a) Formula (3a) wherein the symbols and indices have the same meanings as defined in claim 1 and the compounds can be partially or fully deuterated.

5. Compound according to one or more of claims 1 to 4, characterised in that the compound is selected from the compounds of formula (2b) and (3b),

Formula (2b) Formula (3b) wherein the symbols and indices have the same meanings as defined in claim 1 and the compounds can be partially or fully deuterated.

6. Compound according to one or more of claims 1 to 5, characterised in that the compound is selected from the compounds of formula (2c) and (3c), wherein the symbols have the same meanings as defined in claim 1 and the compounds can be partially or fully deuterated.

7. Compound according to one or more of claims 1 to 6, characterised in that the compound is selected from the compounds of the formulae (2-1) to (2-7) and (3-1) to (3-7),

Formula (2-1) Formula (2-2)

Formula (2-7)

Formula (3-3) Formula (3-4)

Formula (3-5) Formula (3-6)

Formula (3-7) wherein the symbols and indices have the meanings as defined in claim 1 and the compounds can be partially or fully deuterated.

8. Compound according to one or more of claims 1 to 7, characterised in that the compound is selected from the compounds of formulae (2-1 a) to (2-7a) and (3-1 a) to (3-7a),

Formula (2-1 a) Formula (2-2a)

Form la 2-5a Formula (2-6a)

Formula (3-5a) Formula (3-6a)

Formula (3-7a) wherein the symbols have the meanings as defined claim 1 and the compounds can be partially or fully deuterated.

9. Compound according to one or more of claims 1 to 8, characterised in that Ar¹ and Ar² are the same or different at each instance and are independently selected from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthyl, dibenzofuran, dibenzothiophene and carbazole, each of which can be partially or fully deuterated and/or substituted with one or more groups R.

10. Compound according to one or more of claims 1 to 9, characterised in that Ar³ is selected from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthyl, dibenzofuran, dibenzothiophene and carbazole, each of which can be partially or fully deuterated and/or substituted with one or more substituents R.

11. Compound according to one or more of claims 1 to 10, characterised in that the following applies to the symbols and indices:

Ar¹, Ar² are the same or different at each instance and are an aromatic ring system with 6 to 24 aromatic ring atoms, each of which can be partially or fully deuterated and/or can be substituted by one or more substituents R, or a heteroaromatic ring system selected from dibenzofuran, dibenzothiophene, carbazole or benzofuran, each of which can be partially or fully deuterated and/or can be substituted by one or more substituents R; Ar³ is an aromatic ring system with 6 to 24 aromatic ring atoms, which can be partially or fully deuterated and/or can be substituted by one or more substituents R, or a heteroaromatic ring system selected from dibenzofuran, dibenzothiophene or carbazole, each of which can be partially or fully deuterated and/or can be substituted by one or more substituents R;

R, if present, are, identically or differently at each instance, F, Si(R¹)a, a straightchain alkyl or alkoxy group having 1 to 10 C atoms, a branched or cyclic alkyl or alkoxy group having 3 to 10 C atoms, wherein the alkyl or alkoxy group can be substituted by R¹, but is preferably unsubsituted, or an aromatic ring system having 6 to 24 aromatic ring atoms, where the aromatic ring system can be substituted with one or more radicals R¹, but is preferably unsubstituted; where each of these groups can be partially of fully deuterated; and/or where two adjacent radicals R may be connected to each other to form a ring; wherein substituent(s) R, if present on the naphthyl group, are selected from an aromatic ring system having 6 to 24 aromatic ring atoms, which can be substituted with one or more radicals R¹ and can be partially or fully deuterated;

R¹, if present, is identically or differently at each instance an alkyl group having 1 to 10 C atoms, which can be partially or fully deuterated; n is, identically or differently at each instance, 0, 1 , 2 or 3, particularly preferably 0, 1 or 2, very particularly preferably 0 or 1 and most preferred 0; m is, identically or differently at each instance, 0, 1 or 2, particularly preferably 0 or 1 and most preferred 0; o is O or l ; p is 0, 1 or 2.

12. Compound according to one or more of claims 1 to 11 , characterised in that the following applies to the symbols and indices: Ar¹, Ar² are the same or different at each instance and are an aromatic ring system with 6 to 18 aromatic ring atoms, which can be partially or fully deuterated and/or can be substituted by one or more substituents R, or a heteroaromatic ring system selected from dibenzofuran, dibenzothiophene or carbazole, each of which can be partially or fully deuterated and/or can be substituted by one or more substituents R;

L is a single bond or a bivalent aromatic ring system having 6 to 12 aromatic ring atoms, which can be substituted with one or more substituents R and/or which can be partially or fully deuterated;

R, if present, are, identically or differently at each instance, selected from the group consisting of a straight-chain alkyl group having 1 , 2, 3, 4 or 5 C atoms, a branched alkyl group having 3, 4 or 5 C atoms or a cyclic alkyl group having 5 or 6 C atoms, or an aromatic ring system having 6 to 18 aromatic ring atoms, where the aromatic ring system can be substituted with one or more radicals R¹, but is preferably unsubstituted; where each of these groups can be partially of fully deuterated; and/or where two adjacent radicals R may be connected to each other to form a ring; wherein substituent(s) R, if present on the naphthyl group, are selected from an aromatic ring system having 6 to 18 aromatic ring atoms, which can be substituted with one or more radicals R¹ and can be partially or fully deuterated;

R¹, if present, is identically or differently at each instance an alkyl group having 1 , 2, 3, 4 or 5 C atoms, which can be partially or fully deuterated; n is, identically or differently at each instance, 0, 1 or 2; m is, identically or differently at each instance, 0 or 1 ; o is = 0 or 1 , and p is 0 or 1, o + p = 0 or 1.

13. Compound according to one or more of claims 1 to 12, characterised in that the following applies to the symbols and indices:

Ar¹, Ar² are the same or different at each instance and are independently selected from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthyl, dibenzofuran, dibenzothiophene and carbazole, each of which can be partially or fully deuterated and/or substituted with one or more groups R;

Ar³ is selected from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthyl, dibenzofuran, dibenzothiophene and carbazole, each of which can be partially or fully deuterated and/or substituted with one or more substituents R, wherein Ar³ is most preferably a phenyl group, which can be partially or fully deuterated;

R, if present, are, identically or differently at each instance, selected from the group consisting of a straight-chain alkyl group having 1, 2, 3, 4 or 5 C atoms, a branched alkyl group having 3, 4 or 5 C atoms or a cyclic alkyl group having 5 or 6 C atoms, or an aromatic ring system having 6 to 12 aromatic ring atoms, where the aromatic ring system can be substituted with one or more radicals R¹; where each of these groups can be partially of fully deuterated; and/or where two adjacent radicals R may be connected to each other to form a ring; wherein R, if present on the naphthyl group, are selected from phenyl, ortho-, meta- or para-biphenyl, 1-naphthyl or 2-naphthyl where each of these groups can be substituted by one or more substituents R¹, but are preferably unsubstituted, and where each of these groups can be partially or fully deuterated;

R¹, if present, is identically or differently at each instance an alkyl group having 1, 2, 3, 4 or 5 C atoms, which can be partially or fully deuterated; n is, identically or differently at each instance, 0, 1, 2 or 3, particularly preferably 0, 1 or 2, very particularly preferably 0 or 1 and most preferred 0; m is, identically or differently at each instance, 0, 1 or 2, particularly preferably 0 or 1 and most preferred 0; o is = 0 or 1 and p is 0, 1 or 2, preferably p = 0 or 1. Furthermore, in a preferred embodiment, o + p = 0 or 1. Particularly preferred, o = 0 and p = 0.

14. Process for the preparation of the compound according to one or more of claims 1 to 13, characterised by the following reaction steps:

(b) reaction the intermediate obtained in step (a) with a secondary amine bearing a group Ar¹ and a group Ar² in a Hartwig-Buchwald coupling reaction or reaction of the intermediate obtained in step (a) with a triarylamine bearing the groups Ar¹, Ar² and L, wherein L is substituted with a boronic acid or boronic ester as leaving group in a Suzuki coupling reaction.

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

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

17. Electronic device according to claim 16, which is an organic electroluminescent device, characterised in that the compound according to one or more of claims 1 to 13 is used in a hole transporting layer, a hole injection layer, an electron blocking layer, an exciton blocking layer, a charge generation layer or as a matrix material in an emitting layer.