EP4192832A1

EP4192832A1 - Materials for organic electroluminescent devices

Info

Publication number: EP4192832A1
Application number: EP21758339.2A
Authority: EP
Inventors: Amir Hossain Parham; Christian Ehrenreich; Jens ENGELHART
Original assignee: Merck Patent GmbH
Current assignee: Merck Patent GmbH
Priority date: 2020-08-06
Filing date: 2021-08-03
Publication date: 2023-06-14
Also published as: WO2022029096A1; KR20230049107A; CN116157402A; US20230292596A1

Abstract

The present invention relates to compounds which are suitable for use in electronic devices, and to electronic devices, in particular organic electroluminescent devices, containing said compounds.

Description

Materials for organic electroluminescent devices

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

In organic electroluminescent devices (OLEDs), phosphorescent organometallic complexes are frequently used as emitting materials. In general, there is still a need for improvement with OLEDs, especially with OLEDs that exhibit triplet emission (phosphorescence), for example with regard to efficiency, operating voltage and service life. The properties of phosphorescent OLEDs are not only determined by the triplet emitters used. The other materials used, such as matrix materials, are also of particular importance here. Improvements in these materials can therefore also lead to improvements in the OLED properties. Examples of suitable matrix materials for OLEDs are aromatic lactams, such as e.g. in WO 2011/116865, WO 2011/137951, WO 2013/064206 or KR 2015-037703.

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

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

The subject of the present invention is a compound according to formula (1),

where the following applies to the symbols used: X is the same or different on each occurrence CR or N; ^X1 is CR or N; Y is CR ₂ , SiR ₂ , BAr, C=O, O or S; Ar is identical or different on each occurrence and is an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which can be substituted by one or more R radicals; R is the same or different on each occurrence H, D, F, Cl, Br, I, B(OR ¹ ) ₂ , CHO, C(=O)R ¹ , CR ¹ =C(R ¹ ) ₂ , CN, C (=O)OR ¹ , Si(R ¹ )3, NO ₂ , P(=O)(R ¹ ) ₂ , OSO ₂ R ¹ , OR ¹ , S(=O)R ¹ , S(=O) ₂ R ¹ , SR ¹ , a straight-chain alkyl group with 1 to 20 carbon atoms or an alkenyl or alkynyl group with 2 to 20 carbon atoms or a branched or cyclic alkyl group with 3 to 20 carbon atoms, where the alkyl, Alkenyl or alkynyl group can each be substituted by one or more radicals R ¹ , where one or more non-adjacent CH ₂ groups are replaced by -R ¹ C=CR ¹ -, -C≡C-, Si(R ¹ ) ₂ , C =O, C=S, -C(=O)O-, P(=O)(R ¹ ), -O-, -S-, SO or SO ₂ can be replaced, or an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, preferably having 5 to 40 aromatic ring atoms, each of which may be substituted by one or more R ¹ radicals, where two R radicals, if they are bonded to the same carbon atom or silicon atom, mitein may be linked to others and form a ring, and where two radicals R, if they are bonded to adjacent carbon atoms, can be linked to one another and form an aliphatic or heteroaliphatic ring, and where at least one R stands for an aromatic or heteroaromatic ring system and where, in the case of an electron-rich heteroaromatic ring system, R is the attachment of the electron-rich heteroaryl group to the backbone is through a carbon atom;

R ¹ is the same or different on each occurrence, H, D, F, I, B(OR ² ) ₂ , CHO, C(=O)R ² , CR ² =C(R ² ) ₂ , CN, C(=O ) ^OR2 , Si(R2 ) ₃ , _NO2 , P(=O)(R2 ⁾ ² , _OSO2 ^R2 , ^OR2 , S(=O ⁾ R2 , S(=O ₎₂ _R2 ^, a straight-chain alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, the alkyl, alkenyl or alkynyl group each having one or several radicals R ² can be substituted and one or more CH ₂ groups in the above groups by -R ² C═CR ² -, -C═C-, Si(R ² ) ₂ , C═O, C═ S, -C(=O)O-, P(=O)(R ² ), -O-, -S-, SO or SO ₂ can be replaced and one or more H atoms in the above groups can be replaced by D, F, Cl, Br, I, CN or NO ₂ can be replaced, or an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, each of which can be substituted by one or more radicals R ² , with two or more radicals R ¹ can be linked to one another and can form a ring, in the case of an electron-rich heteroaromatic ring system R ¹ the bond of the electron-rich heteroaryl group to the basic skeleton or to R takes place via a carbon atom;

R ² is the same or different on each occurrence and is H, D, F, CN or an aliphatic, aromatic or heteroaromatic organic radical having 1 to 20 carbon atoms, in which one or more H atoms can also be replaced by D or F; two or more substituents R ² can be linked to one another and form a ring, where, in the case of an electron-rich heteroaromatic radical R ² , the bond to the basic skeleton takes place via a carbon atom.

An aryl group within the meaning of this invention contains 6 to 40 carbon atoms; a heteroaryl group within the meaning of this invention contains 2 to 40 carbon atoms and at least one heteroatom, 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 aryl group or heteroaryl group is either a simple aromatic cycle, i.e. benzene, or a simple heteroaromatic cycle, for example pyridine, pyrimidine, thiophene, etc ., or a fused (fused) aryl or heteroaryl group, for example naphthalene, anthracene, phenanthrene, quinoline, isoquinoline, etc. understood. On the other hand, aromatics linked to one another by a single bond, such as biphenyl, are not referred to as aryl or heteroaryl groups, but as aromatic ring systems.

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

An electron-rich heteroaromatic ring system is characterized in that it is a heteroaromatic ring system that does not contain any electron-deficient heteroaryl groups. An electron-deficient heteroaryl group is a six-membered-membered heteroaryl group containing at least one nitrogen atom or a five-membered-membered heteroaryl group containing at least two heteroatoms, one of which is a nitrogen atom and the other is oxygen, sulfur or a substituted nitrogen atom, to which groups further aryl or heteroaryl are attached - Groups can be condensed. In contrast, electron-rich heteroaryl groups are five-membered-membered heteroaryl groups with exactly one heteroatom selected from oxygen, sulfur or substituted nitrogen, to which further aryl groups and/or further electron-rich five-membered-membered heteroaryl groups can be fused. Examples of electron-rich heteroaryl groups are pyrrole, furan, thiophene, indole, benzofuran, benzothiophene, carbazole, dibenzofuran, dibenzothiophene or indenocarbazole. An electron-rich heteroaryl group is also referred to as an electron-rich heteroaromatic radical.

According to the invention, in the case of an electron-rich heteroaromatic ring system R, the electron-rich heteroaryl group is bonded to the basic structure via a carbon atom. If the electron-rich heteroaromatic ring system is, for example, a carbazole group, this is linked to the backbone of the compound of formula (1) via a carbon atom and not via the nitrogen atom. In contrast, linking the carbazole group to the basic structure via the N atom of the carbazole group is not in accordance with the invention. The same applies, for example, when R is an N-phenylcarbazole group. In this case, a compound in which the N-phenylcarbazole group is linked to the backbone via the phenyl group is not covered by the invention because in this case the electron-rich heteroaryl group, i.e. the carbazole group, is linked via the N- atom would be linked (via the phenylene linker) to the backbone. In a preferred embodiment of the invention, the radical R contains no carbazole group.

An electron-poor heteroaromatic ring system is characterized in that it contains at least one electron-poor heteroaryl group and preferably no electron-rich heteroaryl groups.

In the context of the present invention, the term alkyl group is used as a generic term both for linear or branched alkyl groups and for cyclic alkyl groups. Analogously, the terms alkenyl group and alkynyl group are used as generic terms both for linear or branched alkenyl or alkynyl groups and for cyclic alkenyl or alkynyl groups.

In the context of the present invention, an aliphatic hydrocarbon radical or an alkyl group or an alkenyl or alkynyl group, which can contain 1 to 40 carbon atoms, and which also contains individual H atoms or CH ₂ groups, are represented by the groups mentioned above can be substituted, preferably the radicals methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl, neo-pentyl , cyclopentyl, n-hexyl, neo-hexyl, cyclohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, ethenyl, propenyl, butenyl, pentenyl , Cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl or octynyl understood. An alkoxy group OR ¹ having 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, cyclooctyloxy, 2-ethylhexyloxy, pentafluoroethoxy and 2,2,2-trifluoroethoxy understood. A thioalkyl group SR ¹ having 1 to 40 carbon atoms is, in particular, methylthio, ethylthio, n-propylthio, i-propylthio, n-butylthio, i-butylthio, s-butylthio, t-butylthio, n-pentylthio, s-pentylthio, n-hexylthio, cyclohexylthio, n-heptylthio, cycloheptylthio, n-octylthio, 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, it being possible for one or more non-adjacent CH ₂ groups to be replaced by the groups mentioned above; furthermore, one or more H atoms can also be replaced by D, F, Cl, Br, I, CN or NO ₂ , preferably F, Cl or CN, particularly preferably F or CN.

Under an aromatic or heteroaromatic ring system with 5 - 60 aromatic ring atoms, which can be substituted in each case with the above-mentioned radicals R ² or a hydrocarbon radical and which can be linked via any position on the aromatic or heteroaromatic, groups are understood in particular, which ab - are derived from benzene, naphthalene, anthracene, benzanthracene, phenanthrene, pyrene, chrysene, perylene, fluoranthene, naphthacene, pentacene, benzopyrene, biphenyl, biphenylene, terphenyl, triphenylene, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, cis or trans indenofluorene, cis or trans indenocarbazole, cis or trans indolocarbazole, truxene, isotruxene, spirotruxene, spiroisotruxene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene , pyrrole, indole, isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7- quinoline, benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthimidazole, phenanthrimidazole, pyridimidazole, pyrazineimidazole, quinoxalineimidazole, 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-tetraazaperylene, pyrazine, phenazine, phenoxazine, phenothiazine, fluorubine, 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-thiadi- azole, 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 a combination of these systems.

In the context of the present description, the wording that two or more radicals can form a ring system with one another is to be understood, inter alia, as meaning that the two radicals are linked to one another by a chemical bond with formal splitting off of two hydrogen atoms. This is illustrated by the following scheme:

However, the above formulation should also be understood to mean that if one of the two radicals is hydrogen, the second radical binds to the position to which the hydrogen atom was bonded, forming a ring. This should be illustrated by the following scheme:

The following formulas (2) and (3) show further preferred embodiments: where the symbols used have the meanings given above and the aromatic systems can be substituted, as indicated, with one or more R groups, identically or differently.

In a preferred embodiment of the invention, in at least one of the lateral aromatic six-membered rings of the compound of the formula (1), the same or different groups X represent up to twice CR, where R represents an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, preferably having 5 to 40 aromatic ring atoms, each of which may be substituted by one or more R ¹ radicals.

In a preferred embodiment of the invention, a maximum of two X symbols per cycle stand for N, particularly preferably a maximum of one X symbol.

In a preferred embodiment of the invention, X is CR.

In a preferred embodiment, in the case of two adjacent X for X equal to CR, the R radicals are not connected to one another via at least one covalent bond, preferably no R radical is connected to another R radical via at least one covalent bond if X equals CR. More preferably, two or more R radicals do not form a ring when X is CR. This preferably also applies to all other radicals R ¹ and R ² of these radicals R.

The following formulas (4) and (5) show further preferred embodiments: where the symbols used have the meanings given above and the aromatic systems can be substituted, as indicated, with one or more R groups, identically or differently.

In a preferred embodiment of the invention, a maximum of 3 groups R in the formulas (4) and (5) are not H or D, preferably a maximum of 2 groups R.

In a preferred embodiment of the invention, a maximum of 3 groups R in the formulas (4) and (5) are not H or D, preferably a maximum of 2 groups R, where R is then an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms , preferably having 5 to 40 aromatic ring atoms, each of which may be substituted by one or more R ¹ radicals.

In a preferred embodiment of the invention, a maximum of 3 groups R in the formulas (4) and (5) are not H or D, preferably a maximum of 2 groups R, where R is then an aromatic or an electron-deficient heteroaromatic ring system with 5 to 60 aromatic Ring atoms, preferably having 5 to 40 aromatic ring atoms, each of which may be substituted by one or more R ¹ radicals.

In a further preferred embodiment of the compounds listed above and below, Y is CR ₂ , O or S.

In a further preferred embodiment of the invention, the compound is selected from compounds of the formulas (6) to (8): where the symbols used have the meanings given above.

In a preferred embodiment of the invention, a maximum of 3 groups R in the formulas (6) to (8) are not H or D, preferably a maximum of 2 groups R, where R is then an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms , preferably having 5 to 40 aromatic ring atoms, each of which may be substituted by one or more R ¹ radicals.

In a preferred embodiment of the invention, a maximum of 3 groups R in the formulas (6) to (8) are not H or D, preferably a maximum of 2 groups R, where R is then an aromatic or electron-poor heteroaromatic ring system with 5 to 60 aromatic rings - Is atoms, preferably having 5 to 40 aromatic ring atoms, each of which may be substituted by one or more R ¹ radicals.

In a further preferred embodiment of the invention, the compound is selected from compounds of the formulas (9) to (16):

where the symbols used have the meanings given above.

In a preferred embodiment of the invention, a maximum of 3 groups R in the formulas (9) to (16) are not H or D, preferably a maximum of 2 groups R, where R is then an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms , preferably having 5 to 40 aromatic ring atoms, each of which may be substituted by one or more R ¹ radicals.

In a preferred embodiment of the invention, a maximum of 3 groups R in the formulas (9) to (16) are not H or D, preferably a maximum of 2 groups R, where R is then an aromatic or electron-poor heteroaromatic ring system with 5 to 60 aromatic rings - Is atoms, preferably having 5 to 40 aromatic ring atoms, each of which may be substituted by one or more R ¹ radicals. Preferred substituents R, Ar, R ¹ and R ² are described below. In a particularly preferred embodiment of the invention, the preferences given below for R, Ar, R ¹ and R ² occur simultaneously and apply to the structures of the formula (1) and to all preferred embodiments listed above.

In a preferred embodiment of the invention, Ar is an aromatic ring system having 6 to 30 aromatic ring atoms, which may be substituted by one or more R radicals, or a heteroaromatic ring system having 6 to 30 aromatic ring atoms, which may be substituted by one or more radicals R may be substituted. In a particularly preferred embodiment of the invention, Ar is an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, very particularly preferably having 6 to 13 aromatic ring atoms, which is substituted by one or more, preferably non-aromatic, radicals R can be substituted.

Suitable aromatic or heteroaromatic ring systems Ar are selected identically or differently on each occurrence from phenyl, biphenyl, in particular ortho-, meta- or para-biphenyl, terphenyl, in particular ortho-, meta-, para- or branched terphenyl, quater- phenyl, in particular ortho-, meta-, para- or branched quaterphenyl, fluorene, which can be linked via the 1-, 2-, 3- or 4-position, spirobifluorene, which can be linked via the 1-, 2-, 3- - or 4-position can be linked, naphthalene, which can be linked via the 1- or 2-position, indole, benzofuran, benzothiophene, dibenzofuran, which can be linked via the 1-, 2-, 3- or 4-position , Dibenzothiophene, which can be linked via the 1-, 2-, 3- or 4-position, phenanthrene, triphenylene or a combination of two or three of these groups, each with one or more radicals R, preferably non-aromatic R radicals may be substituted.

Further preferred embodiments for Ar when they represent a heteroaromatic ring system are selected from the group consisting of pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, quinazoline, quinoxaline or benzimidazole or a combination of these Groups with one of the groups mentioned above, which can each be substituted with one or more radicals R. If Ar is a heteroaryl group, in particular triazine, pyrimidine, quinazoline or quinoxaline, preference may also be given to aromatic or heteroaromatic radicals R on this heteroaryl group.

In a preferred embodiment of the invention, R is selected the same or different each time it occurs from the group consisting of H, D, F, CN, OR ¹ , a straight-chain alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 C atoms or a branched or cyclic alkyl group with 3 to 10 C atoms, where the alkyl or alkenyl group can be substituted with one or more radicals R ¹ , but is preferably unsubstituted, and where one or more non-adjacent CH ₂ - groups can be replaced by O, or an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, which can each be substituted by one or more radicals R ¹ ; two radicals R can also form an aliphatic ring system with one another or, if they are bonded to the same carbon atom, an aromatic or heteroaromatic ring system. R is particularly preferably selected identically or differently on each occurrence from the group consisting of H, a straight-chain alkyl group having 1 to 6 carbon atoms, in particular having 1, 2, 3 or 4 carbon atoms, or a branched or cyclic alkyl group having 3 to 6 carbon atoms, where the alkyl group can be substituted by one or more radicals R ¹ , but is preferably unsubstituted, or an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, in particular having 6 to 13 aromatic ring atoms, each of which is one or more radicals R ¹ , preferably non-aromatic radicals R ¹ , can be substituted. R is very particularly preferably selected on each occurrence, identically or differently, from the group consisting of H or an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, each of which is replaced by one or more radicals R ¹ , preferably non-aromatic radicals R ¹ , may be substituted. In the case of an electron-rich heteroaromatic ring system, R binds to the basic skeleton via a carbon atom of the electron-rich heteroaryl group, as above described. In a preferred embodiment of the invention, neither R nor any of the substituents R ¹ or R ² attached to R contain a carbazole group.

Suitable aromatic or heteroaromatic ring systems R are selected from phenyl, biphenyl, in particular ortho-, meta- or para-biphenyl, terphenyl, in particular ortho-, meta-, para- or branched terphenyl, quaterphenyl, in particular ortho-, meta- , para- or branched quaterphenyl, fluorene, which can be linked via the 1-, 2-, 3- or 4-position, spirobifluorene, which can be linked via the 1-, 2-, 3- or 4-position , Naphthalene, which can be linked via the 1- or 2-position, indole, benzofuran, benzothiophene, which can be linked via the 1-, 2-, 3- or 4-position, dibenzofuran, carbazole, which via the 1-, 2-, 3- or 4-position can be linked, dibenzothiophene, which can be linked via the 1-, 2-, 3- or 4-position, indenocarbazole, indolocarbazole, pyridine, pyrimidine, pyrazine, pyridazine , triazine, quinoline, quinazoline, benzimidazole, phenanthrene, triphenylene or a combination of two or three of these groups ppen, which can each be substituted with one or more radicals R ¹ . If R is a heteroaryl group, in particular triazine, pyrimidine or quinazoline, preference may also be given to aromatic or heteroaromatic radicals R ¹ on this heteroaryl group.

The groups R, if they stand for an aromatic or heteroaromatic ring system, are preferably selected from the groups of the following formulas R-1 to R-70,

where R ¹ has the meanings given above, the dashed bond represents the bond to a carbon atom of the basic structure in formula (1) or in the preferred embodiments and the following also applies:

Ar ³ is the same or different on each occurrence, a bivalent aromatic or heteroaromatic ring system having 6 to 18 aromatic ring atoms, which can each be substituted with one or more radicals R ¹ , in the case of an electron-rich heteroaromatic ring system, the links via a carbon atom;

A ¹ is identical or different on each occurrence, C(R ¹ ) ₂ , NR ¹ , O or S, preferably O or S; m is 0 or 1, where m=0 means that the Ar ³ group is not present and that the corresponding aromatic or heteroaromatic group is attached directly to a carbon atom of the basic structure in formula (1) or in the preferred embodiments is bound;

In a preferred embodiment, Ar ³ comprises divalent aromatic or heteroaromatic ring systems based on the groups of R-1 to R-70, where m is 0.

If the groups R-1 to R-70 mentioned above have several groups A ¹ for R, then all combinations from the definition of A ¹ are suitable for this. Preferred embodiments are then those in which one group A ¹ is O or S and the other group A ¹ is C(R) ₂ or C(R ¹ ) ₂ or in which both groups A ¹ are S or 0 or in which both groups A ¹ are 0 or S.

If A ¹ is C(R ¹ ) ₂ , the substituents R ¹ bonded to this carbon atom are preferably identical or different on each occurrence and are a linear alkyl group having 1 to 10 carbon atoms or a branched or cyclic alkyl group with 3 to 10 carbon atoms or for an aromatic or heteroaromatic ring system with 5 to 24 aromatic ring atoms, which can also be substituted by one or more radicals R ² . R ¹ very particularly preferably represents a methyl group or a phenyl group. The radicals R ¹ can also form a ring system with one another, which leads to a spiro system.

If Y is CR ₂ , the substituents R which are bonded to this carbon atom are preferably identical or different on each occurrence for a linear alkyl group having 1 to 10 carbon atoms or for a branched or cyclic alkyl group having 3 to 10 C atoms or an aromatic or electron-poor heteroaromatic ring system having 5 to 24 aromatic ring atoms, which can also be substituted by one or more R ¹ radicals. Very particularly preferably, these substituents R are a methyl group or a phenyl group. The radicals R can also form a ring system with one another, which leads to a spiro system.

In a further embodiment of the invention, at least one radical R in the compound of the formula (1) or in the embodiments listed as preferred is an electron-poor heteroaromatic ring system. The electron-poor heteroaromatic ring system is preferably selected from the groups R-35 to R-38, R-45, R-46, R-64 and R-66 to R-70 shown above.

In a further preferred embodiment of the invention, R ¹ is the same or different on each occurrence selected from the group consisting of H, D, F, CN, OR ² , a straight-chain alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms or a branched or cyclic alkyl group having 3 to 10 carbon atoms, the Alkyl or alkenyl group can each be substituted by one or more radicals R ² and one or more non-adjacent CH ₂ groups can be replaced by 0, or an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, each with one or more radicals R ² may be substituted; two or more radicals R ¹ can form an aliphatic ring system with one another. In a particularly preferred embodiment of the invention, R ¹ is identical or different on each occurrence selected from the group consisting of H, a straight-chain alkyl group having 1 to 6 carbon atoms, in particular having 1, 2, 3 or 4 carbon atoms, or one branched or cyclic alkyl group having 3 to 6 carbon atoms, where the alkyl group may be substituted by one or more radicals R ² , but is preferably unsubstituted, or an aromatic or hetero-aromatic ring system having 6 to 24 aromatic ring atoms, each with a or more radicals R ² may be substituted, but is preferably unsubstituted. In the case of an electron-rich heteroaromatic ring system, R ¹ binds to the basic skeleton via a carbon atom, as described above.

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

In a further preferred embodiment of the invention, all radicals R ¹ , if they represent an aromatic or heteroaromatic ring system, or R ² if they represent aromatic or heteroaromatic groups, are selected from the groups R-1 to R-70, which, however, then are each substituted accordingly with R ² or the groups mentioned for R ² .

Furthermore, the groups R do not form any aromatic or heteroaromatic groups fused to the basic structure of the formula (1). In a preferred embodiment of the invention, R in the case of an aromatic or heteroaromatic ring system is selected from the groups comprising aromatic ring systems, electron-poor heteroaromatic ring systems, and dibenzofuran or derivatives thereof or dibenzothiophene or derivatives thereof, each substituted with one or more R ¹ radicals could be.

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

If the compounds of the formula (1) or the preferred embodiments are used as matrix material for a phosphorescent emitter or in a layer which is directly adjacent to a phosphorescent layer, it is also preferred if the compound does not contain any Contains fused aryl or heteroaryl groups in which more than two six-membered rings are fused directly to one another. In particular, it is preferred that the radicals Ar, R, R ¹ and R ² do not contain any fused aryl or heteroaryl groups in which two or more six-membered rings are fused directly to one another. Exceptions to this are phenanthrene, triphenylene, quinazoline and quinoxaline, which can be preferred due to their high triplet energy despite the presence of fused aromatic six-membered rings.

The preferred embodiments mentioned above can be combined with one another at will within the limitations defined in claim 1. In a particularly preferred embodiment of the invention, the preferences mentioned above occur simultaneously. Examples of preferred compounds according to the embodiments listed above are the compounds listed in the table below.

The basic structure of the compounds according to the invention can be represented by the routes outlined in schemes 1 and 2. Schemes 1 and 2 show the synthesis of the compounds, starting from starting materials in which corresponding coupling groups such as Br or Cl are present on one of the aromatic six-membered rings.

First, the basic structure of the formula (1) is built up, which has reactive leaving groups, such as chlorine or bromine. These can be replaced by other substituents in a subsequent reaction, for example by aromatic or heteroaromatic substituents R in a Suzuki coupling reaction.

scheme1

W= CR2,O,S X = CR, N

Scheme 2

W= CR2,O,S X = CR, N

A further subject of the present invention is therefore a process for preparing the compounds according to the invention, characterized by the following steps:

(A) Synthesis of the basic skeleton according to formula (1), which does not yet carry a group R which stands for an aromatic or heteroaromatic ring system; and

(B) Introduction of this group R by at least one coupling reaction.

Formulations of the compounds according to the invention are required for the processing of the compounds according to the invention from the liquid phase, for example by spin coating or by printing processes. These formulations can be, for example, solutions, dispersions or emulsions. It may be preferable to use mixtures of two or more solvents for this. Examples of suitable and preferred solvents are toluene, anisole, o-, m- or p-xylene, methyl benzoate, mesitylene, tetralin, veratrol, THF, methyl THF, THP, chlorobenzene, dioxane, phenoxytoluene, especially 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, α-terpineol, benzothiazole, butyl benzoate, cumene, cyclohexanol, cyclohexanone, cyclohexylbenzene, decalin, dodecylbenzene, ethyl benzoate, indane, NMP, p-cymene , phenetole, 1,4-diisopropylbenzene, dibenzyl ether, diethylene glycol butyl methyl ether, triethylene glycol butyl methyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, tripropylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 2-isopropylnaphthalene, pentylbenzene, hexyl benzene, heptylbenzene, octylbenzene, 1,1-bis(3,4-dimethylphenyl)ethane, 2-methylbiphenyl, 3-methylbiphenyl, 1-methylnaphthalene, 1-ethylnaphthalene, ethyl octanoate, diethyl sebacate, octyl octanoate, heptylbenzene, menthyl isovalerate, Cyclohexylhexanoate or mixtures of these solvents.

A further subject of the present invention is therefore a formulation containing at least one compound according to the invention and at least one further compound. The further compound can be a solvent, for example, in particular one of the abovementioned solvents or a mixture of these solvents. 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 further matrix material. Suitable emitting compounds and other matrix materials are listed below in connection with the organic electroluminescence device. This further connection can also be polymeric.

The compounds according to the invention are suitable for use in an electronic device, in particular in an organic electroluminescent device.

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

Yet another subject matter of the present invention is an electronic device containing at least one connection according to the invention.

An electronic device within the meaning of the present invention is a device which contains at least one layer which contains at least one organic compound. The component can also be inorganic Contain niche materials or layers that are made entirely of inorganic materials.

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

The organic electroluminescent device contains cathode, anode and at least one emitting layer. In addition to these layers, it can also 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 have an exciton-blocking function, for example. However, it should be pointed out that each of these layers does not necessarily have to be present. In this case, the organic electroluminescent device can contain an emitting layer, or it can contain a plurality of emitting layers. If a plurality of emission layers are present, these preferably have a total of a plurality of emission maxima between 380 nm and 750 nm, resulting in white emission overall, ie different emitting compounds which can fluoresce or phosphorescence are used in the emitting layers. Systems with three emitting layers are particularly preferred, with the three layers showing blue, green and orange or red emission. The inventive according to the organic electroluminescent device also be a tandem OLED, in particular for white-emitting OLEDs.

The compound according to the invention according to the embodiments listed above can be used in different layers, depending on the exact structure. Preference is given to an organic electroluminescent device containing a compound of the formula (1) or the preferred embodiments outlined above in an emitting layer as matrix material for phosphorescent emitters or for emitters which exhibit TADF (thermally activated delayed fluorescence), in particular for phosphorescent emitters . The organic electroluminescence device can contain an emitting layer, or it can contain a plurality of emitting layers, with at least one emitting layer containing at least one compound according to the invention as matrix material. Furthermore, the compound according to the invention can also be used in an electron transport layer and/or in a hole blocking layer and/or in a hole transport layer and/or in an exciton blocking layer.

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

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

A further preferred embodiment of the present invention is the use of the compound according to the invention as a matrix material for a phosphorescent emitter in combination with a further matrix material. Suitable matrix materials which can be used in combination with the compounds according to the invention are aromatic ketones, aromatic phosphine oxides or aromatic sulfoxides or sulfones, e.g. B. according to WO 2004/013080, WO 2004/093207, WO 2006/005627 or WO 2010/006680, triarylamines, carbazole derivatives, z. CBP (N,N-biscarbazolylbiphenyl) or WO 2005/039246, US 2005/0069729, JP 2004/288381, EP 1205527, WO 2008/086851 or WO 2013/041176, indolocarbazole derivatives, e.g. B. according to WO 2007/063754 or WO 2008/056746, indenocarbazole derivatives, z. 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, z. B. according to WO 2007/137725, silanes, z. B. according to WO 2005/111172, azaborole or boron ester, z. B. according to WO 2006/117052, triazine derivatives, z. 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. B. according to EP 652273 or WO 2009/062578, diazasilol or tetra azasilol derivatives, z. B. according to WO 2010/054729, diazaphosphole derivatives, z. B. according to WO 2010/054730, bridged carbazole derivatives, z. B. according to WO 2011/042107, WO 2011/060867, WO 2011/088877 and WO 2012/143080, triphenylene derivatives, z. B. according to WO 2012/048781, or dibenzofuran derivatives, z. according to WO 2015/169412, WO 2016/015810, WO 2016/023608, WO 2017/148564 or WO 2017/148565. Likewise, another phosphorescent emitter, which emits at a shorter wavelength than the actual emitter, can be present as a co-host in the mixture, or a compound that does not participate, or does not participate significantly, in charge transport, as described, for example, in WO 2010/108579. In a preferred embodiment of the invention, the materials are used in combination with another matrix material. Preferred co-matrix materials, especially when the compound according to the invention is substituted with an electron-poor heteroaromatic ring system, are selected from the group consisting of biscarbazoles, bridged carbazoles, triarylamines, dibenzofuran-carbazole derivatives and dibenzofuran-amine -Derivatives and the carbazolamines.

Preferred biscarbazoles are the structures of the following formulas (17) and (18), where the following applies to Ar, R and A ¹ :

A ¹ is the same or different on each occurrence NAr ² , O, S or C(R) ₂ ;

Ar is identical or different on each occurrence, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, each of which can be substituted by one or more radicals R;

R is the same or different on each occurrence H, D, F, Cl, Br, I, B(OR ¹ ) ₂ , CHO, C(=O)R ¹ , CR ¹ =C(R ¹ ) ₂ , CN, C (=O)OR ¹ , C(=O)N(R ¹ ) ₂ , Si(R ¹ ) ₃ , N(R ¹ ) ₂ , NO ₂ , P(=O)(R ¹ ) ₂ , OSO ₂ R ¹ , OR ¹ , S(═O)R ¹ , S(═O) ₂ R ¹ , SR ¹ , a straight-chain alkylalkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or one branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group can each be substituted by one or more radicals R ¹ , where one or more non-adjacent CH ₂ groups are replaced by -R ¹ C=CR ¹ -, -C=C-, Si(R ¹ ) ₂ , C=O, C=S, C=NR ¹ , -C(=O)O-, -C(=O)NR ¹ -, NR ¹ , P(=O)(R ¹ ), -O-, -S-, SO or SO ₂ can be replaced, or an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, preferably with 5 to 40 aromatic ring atoms, each of which may be substituted by one or more R ¹ radicals, where two or more R m radicals it may be linked together and form a ring;

In a preferred embodiment of the invention, A ¹ is CR ₂ .

In the case of the formulas (17) and (18), Ar preferably represents an aromatic or heteroaromatic ring system, preferably selected identically or differently on each occurrence from the groups of the following formulas Ar-1 to Ar-82,

where the dashed line represents the bond to the backbone and still applies:

Each time Ar ³ occurs, identically or differently, is a divalent aromatic or heteroaromatic ring system having 6 to 18 aromatic ring atoms, which can each be substituted by one or more R radicals;

Ar ² is an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which may be substituted with one or more R radicals;

A ¹ is the same or different on each occurrence NAr ² , O, S or C(R) ₂ ; n is 0 or 1, where n=0 means that no group A ¹ is bonded to this position and radicals R are bonded to the corresponding carbon atoms instead; m is 0 or 1, where m=0 means that the Ar ³ group is not present and that the corresponding aromatic or heteroaromatic group is bonded directly to the nitrogen atom.

Preferred embodiments of the compounds of the formulas (17) or

(18) are the compounds of the following formulas (17a) or (18a), where the symbols used have the meanings given above according to formula (17) and formula (18).

Examples of suitable compounds of the formula (17) or (18) are the compounds shown below.

Preferred bridged carbazoles are the structures of the following formula (19), where A ¹ and R have the meanings given above according to the formulas (17) and (18) and A ¹ is preferably selected identically or differently on each occurrence from the group consisting of NAr and CR ₂ .

Preferred dibenzofuran derivatives are the compounds of the following formula (20),

where the oxygen can also be replaced by sulfur, so that a dibenzothiophene is formed, L is a single bond or an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, which can also be substituted by one or more R radicals, and R and Ar have the meanings given above. The two Ar groups which bind to the same nitrogen atom, or one Ar group and one L group which bind to the same nitrogen atom, can also be connected to one another, for example to form a carbazole.

Examples of suitable dibenzofuran derivatives are the compounds shown below.

Preferred carbazolamines are the structures of the following formulas (21), (22) and (23),

where L is an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, which may be substituted by one or more R radicals, and R and Ar have the meanings given above according to formula (17) or formula (18).

Examples of suitable carbazolamine derivatives are the compounds shown below. Preferred co-matrix materials, especially when the compound according to the invention is substituted with an electron-rich heteroaromatic ring system, for example a carbazole group, are also selected from the group consisting of triazine derivatives, pyrimidine derivatives, quinazoline derivatives and quinoxaline -Derivatives. Preferred triazine, pyrimidine, quinazoline or quinoxaline derivatives which can be used as a mixture together with the compounds according to the invention are the compounds of the following formulas (24), (25), (26) and (27), where Ar and R have the meanings given above according to the formulas (17) and (18).

Particularly preferred are the triazine derivatives of formula (24) and the quinazoline derivatives of formula (26), especially the triazine derivatives of formula (24).

In a preferred embodiment of the invention, Ar in the formulas (24), (25), (26) and (27) is identical or different on each occurrence, an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, in particular having 6 to 24 aromatic ring atoms which may be substituted by one or more R radicals. Suitable aromatic or heteroaromatic ring systems Ar are the same as those listed above as embodiments for Ar, in particular the structures Ar-1 to Ar-82, as described above as radicals for the compounds of the formulas (17) and (18). are described. Examples of suitable triazine compounds which can be used as matrix materials together with the compounds according to the invention are the compounds shown in the table below.

Examples of suitable quinazoline compounds are those shown in the table below:

Particularly suitable phosphorescent compounds (=triplet emitters) are compounds which, when suitably excited, emit light, preferably in the visible range, and also 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 included, in particular a metal with this atomic number. Preferred phosphorescence emitters are compounds containing copper, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, iridium, palladium, platinum, silver and gold or contain europium, used, in particular compounds containing indium or platinum.

Examples of the emitters described above can be found in applications WO 00/70655, WO 2001/41512, WO 2002/02714, WO 2002/15645, EP 1191613, EP 1191612, EP 1191614, WO 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 2010/099852 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 2015/104045, WO 2015/12018/12015/ 015815, WO 2016/124304, WO 2017/032439, WO 2018/011186, WO 2018/041769, WO 2019/020538, WO 2018/178001, WO 2019/115423 and WO 2019/158453. In general, all phosphorescent complexes are suitable as are used according to the prior art for phosphorescent OLEDs and as are known to the person skilled in the field of organic electroluminescence, and the person skilled in the art can use further phosphorescent complexes without any inventive step.

Examples of phosphorescent dopants are listed below.

In the further layers of the organic electroluminescent device according to the invention it is possible to use all the materials which are customarily used in accordance with the prior art. The person skilled in the art can therefore use all materials known for organic electroluminescent devices in combination with the compounds according to the invention of the formula (1) or the preferred embodiments set out above without any inventive step.

Also preferred is an organic electroluminescence device, characterized in that one or more layers are coated using a sublimation process. The materials are vapour-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.

An organic electroluminescence device is also preferred, characterized in that one or more layers are coated using the OVPD (organic vapor phase deposition) method or with the aid of carrier gas sublimation. The materials are applied at a pressure between 10 ^-5 mbar and 1 bar. A special case of this process is the OVJP (Organic Vapor Jet Printing) process, in which the materials are applied directly through a nozzle and thus structured.

Also preferred is an organic electroluminescent device, characterized in that one or more layers of solution, such as. B. by spin coating, or with any printing method, such as. B. screen printing, flexographic printing, offset printing, LITI (Light Induced Thermal Imaging, thermal transfer printing), ink-jet printing (ink jet printing) or nozzle printing. This requires soluble compounds, which are obtained, for example, by suitable substitution.

Hybrid processes are also possible, in which, for example, one or more layers are applied from solution and one or more further layers are vapor-deposited.

These methods are generally known to the person skilled in the art and can be applied to organic electroluminescent devices containing the compounds according to the invention without any inventive step.

The compounds according to the invention and the organic electroluminescent devices according to the invention are distinguished by one or more of the following properties:

1 . The compounds according to the invention, used as matrix material for phosphorescent emitters, lead to long lifetimes.

2. The compounds according to the invention lead to high efficiencies, in particular to a high EQE. This applies in particular when the compounds are used as matrix material for a phosphorescent emitter.

3. The connections according to the invention lead to low operating voltages. This is especially true when the connections as Matrix material can be used for a phosphorescent emitter.

The invention is explained in more detail by the examples below, without intending to limit it thereby. From the descriptions, the person skilled in the art can carry out the invention in the entire disclosed range and produce further compounds according to the invention without any inventive step and use these in electronic devices or apply the method according to the invention.

examples

Unless stated otherwise, the following syntheses are carried out under a protective gas atmosphere in dried solvents. The solvents and reagents can e.g. B. from Sigma-ALDRICH or ABCR. The corresponding CAS numbers are also given for the compounds known from the literature.

Example a: 8-Bromo-3-phenyl-benzimidazolo[2,1-b][1,3]benzothiazin-12-one

7.6 g (23 mmol) 3-phenylbenzimidazolo[2,1-b][1,3]benzothiazin-12-one are placed in 150 mL DMF. A solution of 4 g (22.5 mmol) of NBS in 100 ml of DMF is then added dropwise at room temperature with the exclusion of light, the mixture is allowed to come to room temperature and the mixture is stirred at this temperature for a further 4 h. The mixture is then mixed with 150 mL water and extracted with CH ₂ Cl ₂ . The organic phase is dried over MgSO ₄ and the solvents removed in vacuo. The product is stirred hot with hexane and filtered off with suction. Yield: 7.9 g (19 mmol), 85% of theory. Th., Purity according to ¹ H-NMR approx. 98%.

The following compounds are obtained analogously:

Example b: 8-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)benzimidazolo[2,1-b][1,3]benzothiazin-12-one

In a four-necked flask, 20.9 g (73.0 mmol, 1.00 eq) 8-chlorobenzimidazolo[2,1-b][1,3]benzothiazin-12-one together with 22.2 g (87.6 mmol, 1.20 eq) bis( pinacolato)diborane and 21.5 g (219 mmol, 3.00 eq) potassium acetate dissolved in 800 ml dioxane and rendered inert with argon. 1.79 g (2.19 mmol, 0.03 eq) of 1,1-bis(diphenylphosphino)ferrocenedichloropalladium(II) complex [95464-05-4] are then added and the reaction mixture is stirred at a bath temperature of 115° C. overnight. After the reaction has ended, the batch is cooled to room temperature and the solvent is removed on a rotary evaporator. The residue is taken up in 250 mL dichloromethane and shaken out with 250 mL water. The aqueous phase is extracted three times with 250 mL dichloromethane, the combined organic phases are dried over sodium sulfate and the solvent is dried on a rotary evaporator removed. The solid obtained is washed out with ethanol at 60.degree. After drying, 22 g (58.0 mmol, 80%) of the desired product are obtained.

The following compounds are obtained analogously:

Example c: 8-[3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]-3-phenylbenzimidazolo[2,1-b][1,3]benzothiazine-12 -on

38.8 g (110.0 mmol) [3-(4,6-diphenyl-1,3,5-triazin-2-yl)phenyl]boronic acid, 44.7 g (110.0 mmol) 8-bromo-3-phenylbenzimidazolo[2, 1-b][1,3]benzothiazin-12-one and 44.7 g (210.0 mmol) tripotassium phosphate are suspended in 500 mL toluene, 500 mL dioxane and 500 mL water. 914 mg (3.0 mmol) of tri-o-tolylphosphine and then 112 mg (0.5 mmol) of palladium(II) acetate are added to this suspension, and the reaction mixture is heated under reflux for 16 h. After cooling, the organic phase is separated off, filtered through silica gel, washed three times with 200 mL water and then evaporated to dryness. The residue is recrystallized from toluene and from dichloromethane/isopropanol and finally sublimed under high vacuum, purity is 99.9%. The yield is 53 g (84 mmol), corresponding to 77% of theory.

The following compounds are obtained analogously:

Manufacture of the OLEDs

The use of the materials according to the invention in OLEDs is presented in the following examples E1 to E20 (see Table 1).

Pretreatment for Examples E1 to E20: Glass flakes coated with structured ITO (indium tin oxide) with a thickness of 50 nm are treated with an oxygen plasma, followed by an argon plasma, before the coating. These plasma-treated glass flakes form the substrates on which the OLEDs are applied.

In principle, OLEDs have the following layer structure: substrate / hole injection layer (HIL) / hole transport layer (HTL) / electron blocking layer (EBL) / emission layer (EML) / optional hole blocking layer (HBL) / electron transport layer (ETL) / optional electron injection layer (EIL). ) and finally a cathode. The cathode is formed by a 100 nm thick aluminum layer. The precise structure of the OLEDs can be found in Table 1. The materials required to produce the OLEDs are shown in Table 2. All materials are thermally evaporated in a vacuum chamber. The emission layer always consists of at least one matrix material (host material, host material) and an emitting dopant (dopant, emitter), which is added to the matrix material or matrix materials by co-evaporation in a certain proportion by volume. A statement such as EG1:IC2:TEG1 (49%:44%:7%) means that the material EG1 accounts for 49% by volume, IC2 for 44% and TEG1 for 7% in the layer present. Analogously, the electron transport layer can also consist of a mixture of two materials.

The OLEDs are characterized by default. For this purpose, the electroluminescence spectra, the current efficiency (SE, measured in cd/A) and the external quantum efficiency (EQE, measured in %) are determined as a function of the luminance, calculated from current-voltage-luminance characteristics assuming a Lambertian radiation characteristic . The electroluminescence spectra are determined at a luminance of 1000 cd/m ² and the CIE 1931 x and y color coordinates are calculated therefrom. Table 3 shows the results obtained in this way. The service life LD is defined as the time after which the luminance drops from the initial luminance to a certain proportion L1 when operated with a constant current density jo. An indication of L1 = 80% in Table 3 means that the service life given in column LD corresponds to the time after which the luminance falls to 80% of its initial value.

Use of the materials according to the invention in OLEDs

In Examples E1 to E18, the compounds EG1 to EG18 according to the invention can be used as matrix material in the emission layer of phosphorescent green OLEDs. The compounds EG5 and EG8 according to the invention can be used in examples E19 to E20 as electron transporters in the ETM layer of phosphorescent green OLEDs.

It can be seen that a compound which contains a carbazole substituent which is linked to the basic structure via a carbon atom, when used as a hole-transporting host material leads to a higher efficiency than a corresponding compound in which the carbazole substituent is linked to the backbone via the nitrogen atom (comparison of V4 with E18).

Table 1: Structure of the OLEDs

Table 2: Structural formulas of the materials for the OLEDs

Table 3: Data of the OLEDs

Claims

Claims Compound according to formula (1), where the following applies to the symbols used:

X is the same or different on each occurrence CR or N;

X ^I is CR or N;

Y is CR ₂ , SiR ₂ , BAr, C=O, O or S;

Each time Ar is identical or different, it is an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which can be substituted by one or more R radicals;

R is the same or different on each occurrence H, D, F, Cl, Br, I, B(OR ¹ ) ₂ , CHO, C(=O)R ¹ , CR ¹ =C(R ¹ ) ₂ , CN, C (=O)OR ¹ , Si(R ¹ ) ₃ , NO ₂ , P(=O)(R ¹ ) ₂ , OSO ₂ R ¹ , OR ¹ , S(=O)R ¹ , S(=O) ₂ R ¹ , SR ¹ , a straight-chain alkyl group with 1 to 20 carbon atoms or an alkenyl or alkynyl group with 2 to 20 carbon atoms or a branched or cyclic alkyl group with 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group may each be substituted by one or more R ¹ radicals, where one or more non-adjacent CH ₂ groups are replaced by -R ¹ C=CR ¹ -, -C=C-, Si(R ¹ ) ₂ , C=O , C=S, -C(=O)O-, P(=O)(R ¹ ), -O-, -S-, SO or SO ₂ can be replaced, or an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, each of which may be substituted by one or more R ¹ radicals, wherein two R groups, when attached to the same carbon atom or silicon atom, can be linked together and form a ring, and wherein two R groups, when attached to adjacent carbon atoms, can be linked together and form an aliphatic or heteroaliphatic ring , and where at least one R is an aromatic or heteroaromatic ring system and where, in the case of an electron-rich heteroaromatic ring system, R, the electron-rich heteroaryl group is bonded to the basic skeleton via a carbon atom;

R ¹ is the same or different on each occurrence, H, D, F, I, B(OR ² ) ₂ , CHO, C(=O)R ² , CR ² =C(R ² ) ₂ , CN, C(=O ) ^OR2 , Si(R2 ) ₃ , _NO2 , P(=O)(R2 ⁾ ² , _OSO2 ^R2 , ^OR2 , S(=O ⁾ R2 , S(=O ₎₂ _R2 ^, a straight-chain alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, the alkyl, alkenyl or alkynyl group each having one or several radicals R ² can be substituted and one or more CH ₂ groups in the above groups can be replaced by -R ² C=CR ² -, -C≡C-, Si(R ² ) ₂ , C=O, C= S, -C(=O)O-, P(=O)(R ² ), -O-, -S-, SO or SO ₂ can be replaced and one or more H atoms in the above groups can be replaced by D, F, Cl, Br, I, CN or NO ₂ can be replaced, or an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, each of which can be substituted by one or more radicals R ² , where two or meh r radicals R ¹ can be linked to one another and can form a ring, in the case of an electron-rich heteroaromatic ring system R ¹ the electron-rich heteroaryl group being bonded to R or to the basic structure via a carbon atom;

R ² is identical or different on each occurrence H, D, F, CN or an aliphatic, aromatic or heteroaromatic organic radical having 1 to 20 carbon atoms, in which one or several H atoms can be replaced by D or F; two or more substituents R ² can be linked to one another and form a ring, in the case of an electron-rich heteroaromatic radical R ² the bond to the basic skeleton being via a carbon atom. Compound according to claim 1, selected from the compounds of formulas (2) or (3), wherein the symbols used have the meanings given in claim 1. Compound according to one or more of Claims 1 or 2, characterized in that a maximum of two X symbols per cycle represent N. Compound according to one or more of Claims 1 to 3, selected from the compounds of the formulas (4) or (5), wherein the symbols used have the meanings given in claim 1. Compound according to one or more of Claims 1 to 4, selected from the compounds of the formulas (6) to (8), wherein the symbols used have the meanings given in claim 1. Compound according to one or more of Claims 1 to 4, selected from the compounds of the formulas (9) to (16),

wherein the symbols used have the meanings given in claim 1. Process for preparing a compound according to one or more of Claims 1 to 6, characterized by the following steps:

(A) Synthesis of the basic structure according to formula (1), which does not yet carry a group R, which represents an aromatic or heteroaromatic ring system;

(B) Introduction of this group R by at least one coupling reaction. Formulation containing at least one compound according to one or more of Claims 1 to 6 and at least one further compound and/or at least one solvent. Use of a compound according to one or more of claims 1 to 6 and/or a formulation according to claim 8 in an electronic device. Electronic device containing at least one compound according to one or more of claims 1 to 6 and/or a formulation according to claim 8. Electronic device according to claim 10, wherein it is an organic electroluminescent device, characterized in that the compound according to one or more of claims 1 to 6 in an emitting layer as a matrix material for phosphorescent or fluorescent emitters or for emitters that Show TADF (thermally activated delayed fluorescence) and/or in an electron transport layer and/or in a hole blocking layer and/or in a hole transport layer and/or in an exciton blocking layer.