WO2025045816A1

WO2025045816A1 - Materials for organic electroluminescent devices

Info

Publication number: WO2025045816A1
Application number: PCT/EP2024/073811
Authority: WO
Inventors: Philipp Stoessel
Original assignee: Merck Patent Gmbh
Priority date: 2023-08-29
Filing date: 2024-08-26
Publication date: 2025-03-06

Abstract

The present invention relates to compounds represented by Formula (1), mixtures and electronic devices containing these compounds, in particular organic electroluminescence devices containing these compounds as matrix materials, hole transport materials or exciton blocker materials.

Description

Materials for organic electroluminescent devices

Field of the Invention

The present invention relates to compounds represented by formula (1) and electronic devices containing these compounds, in particular organic electroluminescence devices containing these compounds as matrix materials, optionally in combination with another compound.

Background of the Invention

Phosphorescent organometallic complexes are often used in organic electroluminescent devices (OLEDs). In general, there is still room for improvement with OLEDs, 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 significant improvements in the OLED properties.

According to the prior art, biindolo phosphite derivative and biindolo phosphorus derivative are used as ligand or polymer preparation material.

CN114560864 A describes phosphite compounds as phosphorus-containing ligands preparation material, and WO22142484 A1 describes the phosphorus ligands as porous polymer preparation material.

According to the prior art, carbazole derivatives, indole derivatives, indole-carbazole olefin derivatives and bicarbazole olefin derivatives are used as matrix materials for phosphorescent emitters.

LIS2021104678 A1 describes the bicarbazole olefin derivative as an electroluminescent material.

CN113698410 A1 describe the indole-carbazole olefin derivative as an electron transport material.

However, there is still need for improvement in the case of use of these materials or in the case of use of mixtures of the materials, especially in relation to efficiency, operating voltage and/or lifetime of the electronic devices, in particular of the organic electroluminescent device.

The problem addressed by the present invention is therefore providing a host material which is suitable for use in an electronic device, especially in a fluorescent or phosphorescent organic electroluminescent device, and which lead to good device properties, especially with regard to an improved lifetime, and providing the corresponding electronic device.

It has now been found that this problem is solved, and the disadvantages from the prior art are eliminated, by the compound according to the following formula (1). The use of such a compound for production of an electronic device leads to very good properties of these devices, especially with regard to lifetime, especially with improved efficiency and/or operating voltage. The advantages are especially also manifested in the presence of the combination of at least one compound of the formula (1) as the first host material and further compound as the second host material, for example in combination with one or more compounds of the formulae (eTMM1), (eTMM2), (eTMM3), (eTMM4) or (eTMM5). of the Invention

The present invention therefore first provides a compound represented by a formula (1):

Formula (1) where the groups and indices that occur are as follows:

Z²⁰ stands for C(R²¹)(R²²), Si(R²¹)(R²²), Ge(R²¹)(R²²), P(O)R²² or SO₂;

X¹¹ is OR¹¹ or N, X¹² is OR¹² or N, X¹³ is OR¹³ or N, X¹⁴ is OR¹⁴ or N, X¹⁵ is OR¹⁵ or N, X¹⁶ is OR¹⁶ or N, X¹⁷ is OR¹⁷ or N, X¹⁸ is OR¹⁸ or N, X¹⁹ is OR¹⁹ or N, and X²⁰ is OR²⁰ or N; R¹¹ to R²⁰ stand on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CHO, CN, N(R³)₂, C(=O)R³, P(=O)(R³)₂, S(=O)R³, S(=O)₂R³, NO₂, Si(R³)₃, Ge(R³)₃, B(R³)₂, B(OR³)₂, OSO₂R³, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 40 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 40 C atoms, each of which may be substituted by one or more radicals R³, where in each case one or more non-adjacent CH₂ groups may be replaced by R³C=CR³, C=C, Si(R³)₂, Ge(R³)₂, Sn(R³)₂, C=O, C=S, C=Se, P(=O)(R³), SO, SO₂, O, S or CONR³ and where one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO₂, an aromatic or heteroaromatic ring system having 5 to 60 ring atoms, which may in each case be substituted by one or more radicals R³, or an aryloxy group having 5 to 60 ring atoms, which may be substituted by one or more radicals R³; wherein two of radicals R¹¹ to R²⁰ may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R³;

R²¹ and R²² stand on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CHO, CN, N(R⁴)₂, C(=O)R⁴, P(=O)(R⁴)₂, S(=O)R⁴, S(=O)₂R⁴, NO₂, Si(R⁴)₃, Ge(R⁴)₃, B(OR⁴)₂, OSO₂R⁴, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 40 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 40 C atoms, each of which may be substituted by one or more radicals R⁴, where in each case one or more non-adjacent CH₂ groups may be replaced by R⁴C=CR⁴, C=C, Si(R⁴)₂, Ge(R⁴)₂, Sn(R⁴)₂, C=O, C=S, C=Se, P(=O)(R⁴), SO, SO₂, O, S or CONR⁴ and where one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO₂, an aromatic or heteroaromatic ring system having 5 to 60 ring atoms, which may in each case be substituted by one or more radicals R⁴, or an aryloxy group having 5 to 60 ring atoms, which may be substituted by one or more radicals R⁴; wherein R²¹ and R²² may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R⁴;

R³ and R⁴ stand on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CHO, CN, N(Ar)₂, C(=O)Ar, P(=O)(Ar)₂, S(=O)Ar, S(=O)₂Ar, NO₂, Si(R')₃, Ge(R')₃, B(OR')₂, OSO₂R , a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 40 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 40 C atoms, each of which may be substituted by one or more radicals R', where in each case one or more non-adjacent CH₂ groups may be replaced by R'C=CR', C=C, Si(R')₂, Ge(R')₂, Sn(R')₂, C=O, C=S, C=Se, P(=O)(R'), SO, SO₂, O, S or CONR' and where one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO₂, an aromatic or heteroaromatic ring system having 5 to 60 ring atoms, which may in each case be substituted by one or more radicals R', or an aryloxy group having 5 to 60 ring atoms, which may be substituted by one or more radicals R'; wherein R³ and R⁴ may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R';

Ar stands on each occurrence, identically or differently, for an aromatic or heteroaromatic ring system having 5 to 60 ring atoms, which may in each case also be substituted by one or more radicals R'; wherein two adjacent substituents R¹¹ to R²⁰, R²¹, R²², R³ and R⁴ may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R',

R stands on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CN, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 20 C atoms, where in each case one or more non-adjacent CH₂ groups may be replaced by SO, SO₂, O, S and where one or more H atoms may be replaced by D, F, Cl, Br or I, or an aromatic or heteroaromatic ring system having 5 to 40 ring atoms.

The invention further provides a mixture containing at least one compound according to formula (1) as described above or hereinafter and at least one further compound and/or at least one solvent, wherein the further compound selected from the group consisting of fluorescent emitters, phosphorescent emitters, TADF (Thermally activated delayed fluorescence) emitters, host materials, matrix materials, electron transport materials, electron injection materials, hole conductor materials, hole injection materials, n-dopants, wide band gap materials, electron blocking materials and hole blocking materials.

The invention further provides a mixture containing at least one compound according to formula (1) as described above or hereinafter and at least one compound of formulae (eTMM1), (eTMM2), (eTMM3), (eTMM4) or (eTMM5)

where the symbols and indices used are as follows. The invention further provides an electronic device containing at least one compound according to formula (1) as described above or described in following preferece or at least one mixture as described above or described in following preferece.

The invention further provides the use of a compound according to formula (1) as described above or described in following preferece in an electronic device.

Detailed Description of the Invention

"D" or "D-atom" in the context of this invention means deuterium.

An aryl group in the context of this invention contains 6 to 60 ring atoms, preferably carbon atoms. A heteroaryl group in the context of this invention contains 5 to 60 ring atoms, where the ring atoms include carbon atoms and at least one heteroatom, with the proviso that the sum total of carbon atoms and heteroatoms adds up to at least 5. The heteroatoms are preferably selected from N, O and/or S. An aryl group or heteroaryl group is understood here to mean either a simple aromatic cycle, i.e. phenyl, derived from benzene, or a simple heteroaromatic cycle, for example derived from pyridine, pyrimidine or thiophene, or a fused aryl or heteroaryl group, for example derived from naphthalene, anthracene, phenanthrene, quinoline or isoquinoline. An aryl group having 6 to 18 carbon atoms is therefore preferably phenyl, naphthyl, phenanthryl or triphenylenyl, with no restriction in the attachment of the aryl group as substituent. The aryl or heteroaryl group in the context of this invention may bear one or more R radicals, where the substituent R is described below.

An aromatic ring system in the context of this invention contains 6 to 60 ring atoms in the ring system. The aromatic ring system also includes aryl groups as described above.

An aromatic ring system having 6 to 18 carbon atoms is preferably selected from phenyl, fully deuterated phenyl, biphenyl, naphthyl, phenanthryl and triphenylenyl.

A heteroaromatic ring system in the context of this invention contains 5 to 60 ring atoms and at least one heteroatom. A preferred heteroaromatic ring system has 10 to 40 ring atoms and at least one heteroatom. The heteroaromatic ring system also includes heteroaryl groups as described above. The heteroatoms in the heteroaromatic ring system are preferably selected from N, O and/or S.

An aromatic or heteroaromatic ring system in the context of this invention is understood to mean a system which does not necessarily contain only aryl or heteroaryl groups, but in which it is also possible for a plurality of aryl or heteroaryl groups to be interrupted by a nonaromatic unit (preferably less than 10% of the atoms other than H), for example a carbon, nitrogen or oxygen atom or a carbonyl group. For example, systems such as 9,9'- spirobifluorene, 9,9-diarylfluorene, triarylamine, diaryl ethers, stilbene, etc. shall thus also be regarded as aromatic or heteroaromatic ring systems in the context of this invention, and likewise systems in which two or more aryl groups are interrupted, for example, by a linear or cyclic alkyl group or by a silyl group. In addition, systems in which two or more aryl or heteroaryl groups are bonded directly to one another, for example biphenyl, terphenyl, quaterphenyl or bipyridine, are likewise encompassed by the definition of the aromatic or heteroaromatic ring system.

An aromatic or heteroaromatic ring system which has 5 to 60 ring atoms and may be joined to the aromatic or heteroaromatic system via any desired positions is understood to mean, for example, groups derived from benzene, naphthalene, anthracene, benzanthracene, phenanthrene, benzophenanthrene, pyrene, chrysene, perylene, fluoranthene, benzofluoranthene, naphthacene, pentacene, benzopyrene, biphenyl, biphenylene, terphenyl, terphenylene, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, cis- ortrans-indenofluorene, cis- ortrans-monobenzoindenofluorene, cis- or trans-dibenzoindenofluorene, truxene, isotruxene, spirotruxene, spiroisotruxene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, indolocarbazole, indenocarbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7- quinoline, benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthimidazole, phenanthrimidazole, pyridimidazole, pyrazinimidazole, quinoxalinimidazole, oxazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, 1 ,2-thiazole, 1 ,3-thiazole, benzothiazole, pyridazine, 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-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.

The abbreviation Ar at each instance is in each case independently an aromatic or heteroaromatic ring system having 5 to 60 ring atoms and may be substituted by one or more R' radicals or heteroaromatic ring system having 5 to 40 ring atoms and may be substituted by one or more R' radicals, where the details for the aromatic ring system or heteroaromatic ring system apply here correspondingly. The R' radical or the R' radicals has/have a definition as described above or described hereinafter. The abbreviation Ar at each instance is preferably in each case independently an aryl group which has 6 to 40 ring atoms and may be substituted by one or more R' radicals, or a heteroaryl group having 5 to 40 ring atoms and containing O or S as heteroatom, which may be substituted by one or more R' radicals, where the details for the aryl group or heteroaryl group and R' as described above or hereinafter are applicable correspondingly.

The abbreviation Ar⁵ is the same or different at each instance and is an aromatic or heteroaromatic ring system which has 5 to 40 ring atoms and may be substituted by one or more nonaromatic R⁷ radicals; at the same time, two Ar⁵ radicals bonded to the same nitrogen atom, phosphorus atom or boron atom may also be bridged to one another by a single bond or a bridge selected from N(R⁷), C(R⁷)₂, O and S, where the R⁷ radical or the substituents R⁷ has/have a definition as described above or hereinafter. Preferably, Ar⁵ is an aryl group having 6 to 40 ring atoms as described above.

A cyclic alkyl, alkoxy or thioalkyl group in the context of this invention is understood to mean a monocyclic, bicyclic or polycyclic group.

In the context of the present invention, a straight-chain alkyl group having 1 to 40 C atoms, branched or cyclic alkyl group having 3 to 40 C atoms is understood to mean, for example, the methyl, ethyl, n-propyl, i-propyl, cyclopropyl, n-butyl, i-butyl, s-butyl, t-butyl, cyclobutyl, 2-methylbutyl, n-pentyl, s-pentyl, t-pentyl, 2-pentyl, neopentyl, cyclopentyl, n-hexyl, s-hexyl, t-hexyl, 2-hexyl, 3-hexyl, neohexyl, cyclohexyl, 1 -methylcyclopentyl, 2-methylpentyl, n- heptyl, 2-heptyl, 3-heptyl, 4-heptyl, cycloheptyl, 1 -methylcyclohexyl, n-octyl, 2-ethylhexyl, cyclooctyl, 1-bicyclo[2.2.2]octyl, 2-bicyclo[2.2.2]octyl, 2-(2,6-dimethyl)octyl, 3-(3,7- dimethyl)octyl, adamantyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, 1 ,1- dimethyl-n-hex-1-yl, 1 , 1-dimethyl-n-hept-1-yl, 1 ,1-dimethyl-n-oct-1-yl, 1 ,1-dimethyl-n-dec- 1-yl, 1 ,1-dimethyl-n-dodec-1-yl, 1 ,1-dimethyl-n-tetradec-1-yl, 1 ,1-dimethyl-n-hexadec-1-yl, 1 ,1-dimethyl-n-octadec-1-yl, 1 , 1-diethyl-n-hex-1-yl, 1 , 1 -diethyl-n-hept-1 -yl, 1 , 1 -diethyl-n- oct-1-yl, 1 , 1-diethyl-n-dec-1-yl, 1 ,1-diethyl-n-dodec-1-yl, 1 , 1-diethyl-n-tetradec-1-yl, 1 ,1- diethyl-n-hexadec-1-yl, 1 ,1-diethyl-n-octadec-1-yl, 1-(n-propyl)cyclohex-1-yl, 1-(n- butyl)cyclohex-1-yl, 1-(n-hexyl)cyclohex-1-yl, 1-(n-octyl)cyclohex-1-yl and 1-(n- decyl)cyclohex-1-yl radicals. A straight-chain alkoxy group having 1 to 40 C atoms or branched alkoxy group having 3 to 40 C atoms is understood to mean, for example, methoxy, trifluoromethoxy, ethoxy, n- propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy or 2-methylbutoxy.

A straight-chain thioalkyl group having 1 to 40 C atoms is understood to mean, for example, S-alkyl groups, for example thiomethyl, 1-thioethyl, 1-thio-i-propyl, 1-thio-n- propyl, 1-thio-i-butyl, 1-thio-n-butyl or 1 -thio-t-butyl.

An aryloxy or heteroaryloxy group having 5 to 60 ring atoms means O-aryl or O-heteroaryl and means that the aryl or heteroaryl group is bonded via an oxygen atom, where the aryl or heteroaryl group is defined as described above.

An aralkyl or heteroaralkyl group having 5 to 40 ring atoms means that an alkyl group as described above is substituted by an aryl group or heteroaryl group, where the aryl or heteroaryl group is defined as described above.

The wording that two or more radicals together may form a ring, in the context of the present description, shall be understood to mean, inter alia, that the two radicals are joined to one another by a chemical bond. This is illustrated by the following scheme:

In addition, however, the abovementioned wording shall 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 shall be illustrated by the following scheme:

In a further embodiment of the invention, a 6-membered cycle in formula (1) comprises not more than one N as aromatic ring atom, meaning that only one of X¹³ to X¹⁸ is N. More preferably, none of X¹³ to X¹⁸ in formula (1) is N. In one embodiment of the compound of the formula (1) or preferred embodiments of the host material of the formula (1), Z²⁰ stands for C(R²¹)(R²²), Si(R²¹)(R²²) or Ge(R²¹)(R²²).

In another embodiment of the compound of the formula (1) or preferred embodiments of the host material of the formula (1), Z²⁰ stands for Si(R²¹)(R²²) or Ge(R²¹)(R²²), particularuly preferred is Si(R²¹)(R²²).

In one embodiment of the compound of the formula (1) or preferred embodiments of the host material of the formula (1), (i) at least one of X¹¹ and X¹² is N; or (ii) X¹¹ is OR¹¹ and X¹² is OR¹², particularuly preferred is (ii) X¹¹ is OR¹¹ and X¹² is OR¹².

In one embodiment of the compound of the formula (1) or preferred embodiments of the host material of the formula (1), (i) at least one of X¹⁹ and X²⁰ is N; or (ii) X¹⁹ is OR¹⁹ and X²⁰ is OR²⁰, particularuly preferred is (ii) X¹⁹ is OR¹⁹ and X²⁰ is OR²⁰.

In one embodiment of the compound of the formula (1) or preferred embodiments of the host material of the formula (1), the compound is represented by at least one of Formulae 1-1 to 1-3:

wherein in Formulae 1-1 to 1-3,

Z²⁰, X¹¹ to X²⁰ have the definition given above or given hereinafter;

X³ is on each occurrence, identically or differently, OR³ or N; and R³ has the definition given above or given hereinafter.

In one embodiment of the compound of the formula (1) or preferred embodiments of the host material of the formula (1),

group is represented by at least one of Formulae 2-1 to 2-3:

wherein in Formulae 2-1 to 2-3,

X¹³ to X¹⁸ have the definition given above or given hereinafter;

Z³⁰ is B(R³¹), N(R³¹), S, O, C(R³¹)(R³²), C(R³¹)=C(R³²), Si(R³¹)(R³²) or Ge(R³¹)(R³²);

R³¹ and R³² each independently refer to the definition of R³;

X³ is on each occurrence, identically or differently, OR³ or N; and wherein two adjacent substituents R³, R³¹ and R³² may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R',

R³ and R' have the definition given above or given hereinafter; and

*” stands on each occurrence, for a binding site to the remainder of formula (1).

In one embodiment of the compound of the formula (1) or preferred embodiments of the host material of the formula (1), Z²⁰ is represented by at least one of Formulae 3-1 to 3-7:

wherein in Formulae 3-1 to 3-7,

Z is C, Si or Ge,

X⁴¹ is OR⁴¹ or N, X⁴² is OR⁴² or N, X⁴³ is OR⁴³ or N, X⁴⁴ is OR⁴⁴ or N,

Z⁴⁰ is a single bond, N(R⁴⁵), S, O, C(R⁴⁵)(R⁴⁶), C(R⁴⁵)=C(R⁴⁶) or Si(R⁴⁵)(R⁴⁶) or Ge(R⁴⁵)(R⁴⁶);

Y⁴¹ is NR⁴⁷ or O, Y⁴² is NR⁴⁸ or O;

R⁴¹ to R⁴⁸ each independently refer to the definition of R⁴;

X⁴ is on each occurrence, identically or differently, OR⁴ or N; wherein R²¹ and R²² may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R⁴; wherein two adjacent substituents R⁴ and R⁴¹ to R⁴⁸ may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R',

R²¹, R²², R⁴ and R' have the definition given above or given hereinafter; and

*, *' and *"' stand on each occurrence, for a binding site to the remainder of formula (1).

In one embodiment of the compound of the formula (1) or preferred embodiments of the host material of the formula (1), at least one of (i) to (viii) is preferred, at least one of (iv), (vii) and (viii) is more preferred: (i) X⁴¹ is CR⁴¹, X⁴² is N, X⁴³ is CR⁴³ and X⁴⁴ is N;

(ii) X⁴¹ is N, X⁴² is CR⁴², X⁴³ is N and X⁴⁴ is CR⁴⁴;

(iii) X⁴¹ is N, X⁴² is N, X⁴³ is N and X⁴⁴ is N;

(iv) X⁴¹ is CR⁴¹, X⁴² is CR⁴², X⁴³ is CR⁴³ and X⁴⁴ is CR⁴⁴;

(v) X⁴¹ is CR⁴¹, X⁴² is N, X⁴³ is N and X⁴⁴ is CR⁴⁴;

(vi) X⁴¹ is N, X⁴² is N, X⁴³ is N and X⁴⁴ is CR⁴⁴;

(vii) X⁴¹ is CR⁴¹, X⁴² is N, X⁴³ is CR⁴³ and X⁴⁴ is CR⁴⁴; or

(viii) X⁴¹ is N, X⁴² is N, X⁴³ is CR⁴³ and X⁴⁴ is CR⁴⁴.

In one embodiment of the compound of the formula (1) or preferred embodiments of the host material of the formula (1), R²¹ and R²² are either identical or different from one another.

In one embodiment of the compound of the formula (1) or preferred embodiments of the host material of the formula (1), at least one of Conditions 1 to 5 is preferred:

X¹¹ and X²⁰ is identical

X¹² and X¹⁹ is identical

X¹³ and X¹⁸ is identical

X¹⁴ and X¹⁷ is identical

X¹⁵ and X¹⁶ is identical.

The compound of the formula (1) or preferred embodiments of the host material of the formula (1), contain(s) preferably at least one deuterium.

In one embodiment of the compound of the formula (1) or preferred embodiments of the host material of the formula (1), at least one of R¹¹ to R²⁰ stands on each occurrence, identically or differently for H or D.

In one embodiment of the compound of the formula (1) or preferred embodiments of the host material of the formula (1), R²¹ or R²² stands on each occurrence, identically or differently for an aromatic or heteroaromatic ring system having 5 to 60 ring atoms, which may in each case be unsubstituted or substituted by one or more D. In one embodiment of the compound of the formula (1) or preferred embodiments of the host material of the formula (1), R³ or R⁴ stands on each occurrence, identically or differently for H or D.

In one embodiment of the compound of the formula (1) or preferred embodiments of the host material of the formula (1), R' stands on each occurrence, identically or differently for H or D.

In one embodiment of the compound of the formula (1) or preferred embodiments of the host material of the formula (1), the degree of deuteration of the compound is about 1 mol% to 100 mol%, is preferably at least 10 mol% to 100 mol%, is particularly preferably 50 mol% to 95 mol% and is particularly preferably 70 mol% to 90 mol%.

In one embodiment of the compound of the formula (1) or preferred embodiments of the host material of the formula (1), R¹¹ to R²⁰ stand on each occurrence, identically or differently for H, D, F, CN, Si(R³)₃, N(R³)₂, Ge(R³)₃, B(R³)₂, straight-chain alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl groups having 3 to 20 C atoms, each of which may be substituted by one or more radicals R³, where in each case one or more non-adjacent CH₂ groups may be replaced by R³C=CR³ or C≡C ; aromatic ring systems having 6 to 40 ring atoms or heteroaromatic ring systems having 5 to 40 ring atoms, which may in each case be substituted by one or more radicals R³; or an aryloxy group having 6 to 40 ring atoms, which may in each case be substituted by one or more radicals R³, and R³ has the definition given above or given hereinafter.

In one embodiment of the compound of the formula (1) or preferred embodiments of the host material of the formula (1), R²¹ and R²² stand on each occurrence, identically or differently for H, D, F, CN, Si(R⁴)₃, N(R⁴)₂, Si(R⁴)₃, straight-chain alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl groups having 3 to 20 C atoms, each of which may be substituted by one or more radicals R⁴, where in each case one or more non-adjacent CH₂ groups may be replaced by R⁴C=CR⁴ or C≡C; aromatic ring systems having 6 to 40 ring atoms or heteroaromatic ring systems having 5 to 40 ring atoms, which may in each case be substituted by one or more radicals R⁴; or an aryloxy group having 6 to 40 ring atoms, which may in each case be substituted by one or more radicals R⁴, more preferred are identically or differently at each occurrence, aromatic ring systems having 6 to 40 ring atoms or heteroaromatic ring systems having 5 to 40 ring atoms, which may in each case be substituted by one or more radicals R⁴, and R⁴ has the definition given above or given hereinafter.

In one embodiment of the compound of the formula (1) or preferred embodiments of the host material of the formula (1), R³ and R⁴ stand on each occurrence, identically or differently for H, D, F, CN, Si(R')₃, N(R')₂, Ge(R')₃, straight-chain alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl groups having 3 to 20 C atoms, each of which may be substituted by one or more radicals R', where in each case one or more non-adjacent CH₂ groups may be replaced by R'C=CR' or C≡C; aromatic ring systems having 6 to 40 ring atoms or heteroaromatic ring systems having 5 to 40 ring atoms, which may in each case be substituted by one or more radicals R'; or an aryloxy group having 6 to 40 ring atoms, which may in each case be substituted by one or more radicals R', and R' has the definition given above or given hereinafter.

Examples of suitable compounds of formula (1) are the structures listed below in Table 1.

Table 1

The compounds according to the invention can be prepared by means of known synthesis methods, such as following methods. The following synthesis schemes show the compounds used to simplify structures with a small number of substituents. This does not exclude the presence of any other substituents in the procedures.

Particularly suitable compounds of the formula (1), are the compounds H1 to H12 of table 2.

Table 2

The methods shown for the synthesis of the compounds according to the invention are to be understood by way of example. The skilled person may develop alternative methods of synthesis within the framework of his general knowledge.

The compound (b) according to the invention can be prepared by means of known synthesis methods, see scheme 1. Literature known 1 ,1 '-bi-9H -carbazole derivatives (a) are double de-protonated with strong bases, preferably with organo-lithium compounds (e.g. n-buthylllitium) in an suitable solvent, preferably an ether (e.g. diethyl-, di-n-butyl-, di-n- hexyl-, methyl-t-butyl-ether or an cyclic ether like THF). The double de-protonated species is then treated with a metal electrophile R₂MHal₂ yielding the compound (b). The raw products obtained are purified by standard procedures, like chromatography, crystallization and fractionated sublimation.

Scheme 1 :

The use of 1 ,1 '-bi-9H -carbazole derivatives (a) and SiCl₄, GeCl₄ or CCl₄ as metal electrophile in the stochiometric ratio of 2 to 1 yields the spiro compounds (c), see scheme 2. Scheme 2:

If two different 1 , T-bi-9H-carbazole derivatives (a) are used in a statistical or sequential synthesis, the unsymmetrical spiro compounds (c) are obtained.

In a similar manner as described above 7, 7'-Bi-1H-indole (d1), 7, 7'-bi-1H-benzimidazole (d2), 7,7'-bi-1H-benzpyrazole (d3) and 7,7'-bi-1H-benzotriazole (d4) can be used as starting material to obtain compounds (e1-e4) and (f1-f4) according to the invention, see scheme 3.

Scheme 3:

If two different 7,7'-Bi-1H-indole (d1), 7, 7'-bi-1H-benzimidazole (d2), 7,7'-bi-1H- benzpyrazole (d3) and 7, 7'-bi-1H-benzotriazole (d4) are used in a statistical or sequential synthesis, the unsymmetrical spiro compounds (f1-f4) are obtained.

Detailed reaction conditions are known to those skilled in the art or are described in the example part. By following these procedures, if necessary, by purification, such as re-crystallization or sublimation, the compounds of formula (1) can be obtained in high purity, preferably more than 99.9% (determined by ¹H NMR and/or HPLC).

For the processing of the compounds of the invention from liquid phase, for example by spin-coating or by printing methods, formulations of the compounds of the invention or of mixtures of compounds of the invention with further functional materials, such as matrix materials, fluorescent emitters, phosphorescent emitters and/or emitters that exhibit TADF, 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 and preferred solvents are, for example, toluene, anisole, o-, m- or p-xylene, methyl benzoate, mesitylene, tetralin, veratrole, THF, methyl-THF, THP, chlorobenzene, dioxane, phenoxytoluene, 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, a-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, hexylbenzene, 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, cyclohexyl hexanoate or mixtures of these solvents.

The inventive compounds of the formula (1) or preferred embodiments of the host material of the formula (1) (optionally one compound of the formulae 1-1 to 1-3) as described above, are suitable for use in an organic electroluminescent device, especially as matrix material.

When the compound of the invention is used as matrix material or, synonymously, host material in an emitting layer, it is preferably used in combination with a further compound.

The invention therefore further provides a mixture comprising at least one compound of the formula (1) or at least one preferred compound of one of the formulae 1-1 to 1-3, or a compound from table 1 or table 2 and at least one further compound selected from the group of the matrix materials, phosphorescent emitters, fluorescent emitters and/or emitters that exhibit TADF (thermally activated delayed fluorescence). Suitable matrix materials and emitters that can be used in this mixture of the invention are described hereinafter.

The present invention likewise further provides a formulation comprising at least one compound of the invention, as described above, or a mixture of the invention, as described above, and at least one solvent. The solvent may be an abovementioned solvent or a mixture of these solvents.

The present invention further provides an organic electronic device comprising an anode, a cathode and at least one organic layer, comprising at least one compound of the formula (1), or at least one preferred compound of one of the formulae 1-1 to 1-3, or a compound from table 1 or table 2.

The organic electronic device may be selected, for example, from organic integrated circuits (OlCs), organic field-effect transistors (OFETs), organic thin-film transistors (OTFTs), organic electroluminescent devices, organic solar cells (OSCs), organic optical detectors, organic photoreceptors.

The organic electronic device is preferably an organic electroluminescent device.

The organic electroluminescent device (synonymous with organic electroluminescence device) of the invention is, for example, an organic light-emitting transistor (OLET), an organic field quench device (OFQD), an organic light-emitting electrochemical cell (OLEC, LEC, LEEC), an organic laser diode (O-laser) or an organic light-emitting diode (OLED). The organic electroluminescent device of the invention is especially an organic light-emitting diode or an organic light-emitting electrochemical cell. The device of the invention is more preferably an OLED.

The organic layer of the device of the invention preferably comprises, as well as a light- emitting layer (EML), a hole injection layer (HIL), a hole transport layer (HTL), a hole blocker layer (HBL), an electron transport layer (ETL), an electron injection layer (EIL), an exciton blocker layer, an electron blocker layer and/or charge generation layers. It is also possible for the device of the invention to include two or more layers from this group, preferably selected from EML, HIL, HTL, ETL, EIL and HBL. It is likewise possible for interlayers having an exciton-blocking function, for example, to be introduced between two emitting layers.

If a plurality of emission layers are present, these preferably 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 are used in the emitting layers. It is also possible for two or more fluorescent and/or phosphorescent compounds to be present in an emitting layer. Especially preferred are systems having three emitting layers, where the three layers show blue, green and orange or red emission. As an alternative to the combination as described above, an emitting layer may also show yellow emission. Combinations of this kind are known to those skilled in the art. The organic electroluminescent device of the invention may also be a tandem electroluminescent device, especially for white-emitting OLEDs.

The device may also comprise inorganic materials or else layers formed entirely from inorganic materials.

It presents no difficulties at all to the person skilled in the art to consider a multitude of materials known in the prior art in order to select suitable materials for use in the above- described layers of the organic electroluminescent device. The person skilled in the art here will reflect in a customary manner on the chemical and physical properties of materials, since he knows that the materials interact with one another in an organic electroluminescent device. This relates, for example, to the energy levels of the orbitals (HOMO, LIIMO) or else the triplet and singlet energy levels, but also other material properties.

The inventive compound of the formula (1) as described above or as described as preferred can be used in different layers, according to the exact structure. Preference is given to an organic electroluminescent device comprising a compound of formula (1) or the above- recited embodiments in an emitting layer as matrix material for fluorescent emitters, phosphorescent emitters or for emitters that exhibit TADF (thermally activated delayed fluorescence), especially for phosphorescent emitters. In addition, the compound of the invention can also be used in an electron transport layer and/or in a hole transport layer and/or in an exciton blocker layer and/or in a hole blocker layer. Particular preference is given to using the compound of the invention as matrix material in an emitting layer or as hole transport material or exciton blocker material in a hole transport layer or exciton blocker layer.

The present invention further provides an organic electronic device as described above, wherein the organic layer comprises at least one light-emitting layer comprising at least one compound of the formula (1), or at least one preferred compound of one of the formulae 1- 1 to 1-3, or a compound from table 1 or table 2. In one embodiment of the device of the invention, at least one further matrix material is selected in the light-emitting layer, and this is used together with compounds of the formula (1) or with compounds of one of the formulae 1-1 to 1-3 as described above or with the compounds from table 1 or 2.

The present invention accordingly further provides an organic electronic device as described above, wherein the organic layer comprises at least one light-emitting layer comprising at least one compound of the formula (1), or at least one preferred compound of one of the formulae 1-1 to 1-3, or a compound from table 1 or 2, and at least one further matrix material.

The present invention accordingly further provides an organic electronic device as described above, wherein the organic layer comprises at least one light-emitting layer comprising at least one compound of the formula (1), or at least one preferred compound of one of the formulae 1-1 to 1-3, or a compound from table 1 or 2, and two further matrix materials.

Suitable matrix materials that can be used in combination with the compounds of the invention are aromatic ketones, aromatic phosphine oxides or aromatic sulfoxides or sulfones, triarylamines, carbazole derivatives, biscarbazoles, indolocarbazole derivatives, indenocarbazole derivatives, azacarbazole derivatives, bipolar matrix materials, azaboroles or boronic esters, triazine derivatives, zinc complexes, diazasilole or tetraazasilole derivatives, diazaphosphole derivatives, bridged carbazole derivatives, triphenylene derivatives or dibenzofuran derivatives. It is likewise possible for a further phosphorescent emitter having shorter-wavelength emission than the actual emitter to be present as co-host in the mixture, or a compound not involved in charge transport to a significant extent, if at all, for example a wide band-gap compound.

A wide-band gap material is understood herein to mean a material within the scope of the disclosure of US 7,294,849 which is characterized by a band gap of at least 3.5 eV, the band gap being understood to mean the gap between the HOMO and LUMO energy of a material.

Particularly suitable matrix materials that can advantageously be combined with a compound according to the formula (1) or with a compound of one of the formulae 1-1 to 1- 3 as described above or hereinafter in a mixed matrix system may be selected from the compounds of the formulae (eTMM1), (eTMM2), (eTMM3), (eTMM4) or (eTMM5), as described hereinafter.

The invention accordingly further provides a mixture comprising at least one compound according to formula (1) or one compound of the formulae 1-1 to 1-3 as described aboveand at least one compound of the formulae (eTMM1), (eTMM2), (eTMM3), (eTMM4) and/or (eTMM5), as described hereinafter.

The invention accordingly further provides an organic electronic device comprising an anode, a cathode and at least one organic layer comprising at least one light-emitting layer, wherein the at least one light-emitting layer comprises at least one compound of the formula (1) as matrix material 1 , as described above or as described with preference, and at least one compound of the formulae (eTMM1), (eTMM2), (eTMM3), (eTMM4) and/or (eTMM5) as matrix material 2,

where the symbols and indices used are as follows:

X stands on each occurrence, identically or differently, for N or CR⁶, preferably for N;

L² is the same or different at each instance and is a single bond or an aromatic or heteroaromatic ring system which has 5 to 24 ring atoms and may be substituted in each case by one or more R⁷ radicals;

R# is the same or different instance and is D, F, CN or an aromatic ring system which has 6 to 24 ring atoms and may be substituted by one or more R⁶ radicals, and two adjacent substituents R# together may form an aromatic, heteroaromatic, aliphatic, heteroaliphatic ring system that may be substituted by one or more R⁷ radicals;

Y is the same or different at each instance and is N or CR⁷, with exclusion of the possibility that two Y alongside one another are both N;

V² is O or S;

R⁶ at each instance is the same or different and is H, D, F, CN, 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, where the alkyl, alkenyl or alkynyl group may in each case be substituted by one or more R⁷ radicals and where one or more nonadjacent CH₂ groups may be replaced by Si(R⁷)₂, C=O, NR⁷, O, S or CONR⁷, or an aromatic or heteroaromatic ring system which has 5 to 60 ring atoms and may be substituted in each case by one or more R⁷ radicals; it is also possible here for two R⁶ radicals together to form an aromatic, heteroaromatic, aliphatic, or heteroaliphatic ring system;

Ar⁵ is the same or different at each instance and is an aromatic or heteroaromatic ring system which has 5 to 40 ring atoms and may be substituted by one or more R⁷ radicals;

R⁷ is the same or different at each instance and is H, D, F, Cl, Br, I, N(R⁸)₂, CN, NO₂, OR⁸, SR⁸, Si(R⁸)₃, B(OR⁸)₂, C(=O)R⁸, P(=O)(R⁸)₂, S(=O)R⁸, S(=O)₂ R⁸, OSO₂R⁸, 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, where the alkyl, alkenyl or alkynyl group may in each case be substituted by

Q one or more R radicals and where one or more nonadjacent CH₂ groups may be replaced by Si(R⁸)₂, C=O, NR⁸, O, S or CONR⁸, or an aromatic or heteroaromatic ring system which has 5 to 40 ring atoms and may be substituted in each case by one or more R⁸ radicals; at the same time, two or more R⁷ radicals together may form an aromatic, heteroaromatic, aliphatic or heteroaliphatic ring system;

R⁸ is the same or different at each instance and is H, D, F or an aliphatic, aromatic or heteroaromatic organic radical, especially a hydrocarbyl radical, having 1 to 20 carbon atoms, in which one or more hydrogen atoms may also be replaced by F; b1 is 0, 1 , 2, 3 or 4; b2 is 0, 1 , 2 or 3.

Preferred compounds of the formula (eTMM1) are the compounds of the formulae (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d), (eTMM1e) and (eTMM1f)

where the symbols and indices for these formulae are defined as follows: W, W¹ are the same or different at each instance and are O, S, C(R^W)₂ or N-Ar⁵;

R^w is the same or different at each instance and is a straight-chain alkyl group having 1 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where one or more hydrogen atoms may be replaced by D, F or CN, or an aromatic or heteroaromatic ring system which has 5 to 40 ring atoms and may be substituted by one or more substituents selected from D, F, CN, a straight-chain alkyl group having 1 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where one or more hydrogen atoms in the alkyl group on the aromatic or heteroaromatic ring system may be replaced by D, F or CN; at the same time, the two R^w radicals that bind to the same carbon atom may also form a ring system with one another;

A is the same or different at each instance and is CR⁷ or N, where not more than two A groups per cycle are N and where A is C when L² is bonded to that position; a3 is the same or different at each instance and is 0, 1 , 2, 3 or 4; b3 is the same or different at each instance and is 0, 1 , 2 or 3;

Ring

is derived from an aryl group which has 6 to 20 ring atoms and may be substituted by one or more substituents R#;

L₃ is an aromatic ring system having 6 to 40 ring atoms or a heteroaromatic ring system having 5 to 40 ring atoms, which may be substituted by one or more R⁷ radicals; and where L² , X, Ar⁵ , R⁷ and R# have the definitions given above.

Preferred compounds of the formula (eTMM2) are the compounds of the formula (eTMM2a):

where Y, V² , L₂, R⁷ and a3 have a definition given above, D is deuterium, and a4 is 0, 1 or

2.

Preferred compounds of the formula (eTMM3) are the compounds of the formula (eTMM3a):

Formula (eTMM3a) where the symbols and indices for this formula (eTMM3a) are defined as follows:

W¹ is the same or different at each instance and is O, S, C(R^W)₂ or N-Ar⁵;

#X is CR or NAr⁵, preferably NAr⁵;

R^w is the same or different at each instance and is a straight-chain alkyl group having

1 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where one or more hydrogen atoms may be replaced by D, F or CN, or an aromatic or heteroaromatic ring system which has 5 to 40 ring atoms and may be substituted by one or more substituents selected from D, F, CN, a straight-chain alkyl group having 1 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where one or more hydrogen atoms in the alkyl group on the aromatic or heteroaromatic ring system may be replaced by D, F or CN; a3 is the same or different at each instance and is 0, 1 , 2, 3 or 4;

where L² , Ar⁵ and R# have the definitions given above.

In compounds of the formula (eTMM1a), W is preferably O or N-Ar⁵.

In compounds of the formula (eTMM1a), A is preferably the same or different at each instance and is CR⁷ , where A is C when L² is bonded to that position.

In compounds of the formula (eTMM1e) or (eTMM3a), W¹ is preferably O, C(R^W)₂ or N-

Ar⁵ , more preferably N- Ar⁵.

In compounds of the formula (eTMM1f), L³ is preferably a heteroaromatic ring system which has 9 to 30 ring atoms and may be substituted by one or more R⁷ radicals.

In a preferred embodiment of the compounds of the formulae (eTMM1), (eTMM1a), (eTMM1b), (eTMM1e), (eTMM1d), (eTMM1e), (eTMM1f), (eTMM2), (eTMM2a), (eTMM3), (eTMM3a), (eTMM4) and (eTMM5) that can be combined in accordance with the invention with above-detailed compounds of the invention, as described above, R⁷ is the same or different at each instance and is selected from the group consisting of H, D, F, CN, a straight-chain alkyl group having 1 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl group may in each case be substituted by one or more R⁸ radicals, or an aromatic heteroaromatic ring system which has 5 to 60 ring atoms, preferably 5 to 40 ring atoms, and may be substituted in each case by one or more R⁸ radicals.

In a particularly preferred embodiment of the compounds of the formulae (eTMM1), (eTMM1a), (eTMM1b), (eTMM1e), (eTMM1d), (eTMM1e), (eTMM1f), (eTMM2), (eTMM2a), (eTMM3), (eTMM3a), (eTMM4) or (eTMM5) that can be combined in accordance with above-detailed compounds of the invention, as described above, R⁷ is the same or different at each instance and is selected from the group consisting of H, D or an aromatic or heteroaromatic ring system which has 6 to 30 ring atoms and may be substituted by one or more R⁸ radicals.

The preparation of the compounds of the formulae (eTMM1), (eTMM1a), (eTMM1 b), (eTMM1c), (eTMM1d), (eTMM1e), (eTMM1f), (eTMM2), (eTMM2a), (eTMM3), (eTMM3a), (eTMM4) and (eTMM5) is generally known, and some of the compounds are commercially available.

If the matrix material is a deuterated compound, it is possible that the matrix material is a mixture of deuterated compounds of the same chemical base structure that differ merely by the level of deuteration.

In a preferred embodiment of the matrix material, the latter is a mixture of deuterated compounds of the invention or compounds of the formulae (eTMM1), (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d), (eTMM1e), (eTMM1f), (eTMM2), (eTMM2a), (eTMM3), (eTMM3a), (eTMM4) or (eTMM5), as described above, where the deuteration level of these compounds is at least 50mol% to 90mol%, preferably 70mol% to 100mol%. Corresponding deuteration methods are known to the person skilled in the art and are described, for example, in KR2016041014, WO2017/122988, KR202005282,

KR101978651 and WO2018/110887 or in Bulletin of the Chemical Society of Japan, 2021 , 94(2), 600-605 or Asian Journal of Organic Chemistry, 2017, 6(8), 1063-1071.

A suitable method of deuterating a compound by exchange of one or more hydrogen atoms for deuterium atoms is a treatment of the compound to be deuterated in the presence of a platinum catalyst or palladium catalyst and a deuterium source. The term “deuterium source” means any compound that contains one or more deuterium atoms and is able to release them under suitable conditions.

The platinum catalyst is preferably dry platinum on charcoal, preferably 5% dry platinum on charcoal. The palladium catalyst is preferably dry palladium on charcoal, preferably 5% dry palladium on charcoal. A suitable deuterium source is D₂O, benzene-d6, chloroform-d, acetonitrile-d3, acetone-d6, acetic acid-d4, methanol-d4 or toluene-d8. A preferred deuterium source is D₂O or a combination of D₂O and a fully deuterated organic solvent. A particularly preferred deuterium source is the combination of D₂O with a fully deuterated organic solvent, where the fully deuterated solvent here is not restricted. Particularly suitable fully deuterated solvents are benzene-d6 and toluene-d8. A particularly preferred deuterium source is a combination of D₂O and toluene-d8. The reaction is preferably conducted with heating, more preferably with heating to temperatures between 100°C and 200°C. In addition, the reaction is preferably conducted under pressure. Suitable compounds of the formula (eTMM1) are known, for example, from the following publications: WO2007/077810A1, WO2008/056746A1, WO2010/136109A1, WO2011/057706A2, WO2011/160757A1, WO2012/023947A1, WO2012/048781 A1, WO2013/077352A1, WO2013147205A1, WO2013/083216A1 , WO2014/094963A1 , WO2014/007564A1, WO2014/015931 A1, WO2015/090504A2, WO2015/105251 A1, WO2015/169412A1, WO2016/015810A1, WO2016/013875A1, WO2016/010402A1, WO2016/033167A1, WO2017/178311A1, WO2017/076485A1, WO2017/186760A1, WO2018/004096A1, WO2018/016742A1, WO2018/123783A1, WO2018/159964A1, WO2018/174678A1, WO2018/174679A1, WO2018/174681 A1, WO2018/174682A1, WO2019/177407A1, WO2019/245164A1, WO2019/240473A1, WO2019/017730A1, WO2019/017731 A1, WO2019/017734A1, WO2019/145316A1, WO2019/121458A1, WO2020/130381 A1, WO2020/130509A1, WO2020/169241 A1, WO2020/141949A1, WO2021/066623A1, WO2021/101220A1, WO2021/037401A1, WO2021/180614A1, WO2021/239772A1, WO2022/015084A1, WO2022/025714A1, WO2022/055169A1, EP3575296A1, EP3591728A1, US2014/0361254A1, US2014/0361268A1, KR20210036304A, KR20210036857A, KR2021147993A, JP2011/160367A2 and JP2017/107992A2.

Suitable compounds of the formula (eTMM2) are known, for example, from the following publications: WO2015/182872A1, WO2015/105316A1, WO2017/109637A1, WO2018/060307A1, WO2018/151479A2, WO2018/088665A2, WO2018/060218A1, WO2018/234932A1, WO2019/058200A1, WO2019/017730A1, WO2019/017731 A1, WO2019/066282A1, WO2019/059577A1, WO2020/141949A1, WO2020/067657A1, WO2022063744A1, WO2022/090108A1, WO2022/207678A1, WO2023061998A1, KR20170139443A, KR20190036867A, KR2019035308A, KR2021147993A, CN110294753A, CN110437241 A, US2016/072078A1, US2019/148646A1.

Suitable compounds of the formula (eTMM3) are known, for example, from the following publications: WO2017/160089A1, WO2019/017730A1, WO2019/017731 A1, WO2020/032424A1.

Suitable compounds of the formula (eTMM5) are known, for example, from the following publications: WO2015/093878A1, WO2016/033167A1, WO2017/183859A1, WO2017/188655A1 , WO2018/159964A1.

For a combination with the compounds of the invention as described above or described as preferred, suitable compounds are in particular those of the formulae (eTMM1), (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d), (eTMM1e), (eTMM1f), (eTMM2) and/or (eTMM2a), as described above or described as preferred, or corresponding compounds in the tables that follow that are covered by these formulae. Particular preference is given here to the compounds of the formulae (eTMM1), (eTMM1a), (eTMM1 b), (eTMM1c), (eTMM1d), (eTMM1e) and/or (eTMM1f).

Further examples of suitable host materials of the formulae (eTMM1), (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d), (eTMM1e), (eTMM1f), (eTMM2), (eTMM2a), (eTMM3), (eTMM3a), (eTMM4) and (eTMM5) that can be combined in accordance with the invention with above-detailed compounds of the invention are the structures shown in table 3.

Table 3

Particularly suitable compounds of the formulae (eTMM1), (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d), (eTMM1e), (eTMM1f) and/or (eTMM2) that can be combined in accordance with the invention with above-detailed compounds of the invention, as described above, and are used in the electroluminescent device of the invention or in the mixture, are the compounds E1 to E41 in table 4.

The aforementioned host materials of the invention and the embodiments thereof that have been described as preferred may be combined in the device of the invention in any desired manner with the aforementioned matrix material/host materials, the matrix material/host materials of the formulae (eTMM1), (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d), (eTMM1e), (eTMM1f), (eTMM2), (eTMM2a), (eTMM3), (eTMM3a), (eTMM4) or (eTMM5), and the embodiments there of that have been described as preferred from table 1 or the compounds H1 to H12 from table 2.

The aforementioned host materials of the formula (1) and the embodiments thereof that are described as preferred or the compounds from table 1 and compounds H1 to H12 can be combined as desired in the device of the invention with the aforementioned matrix materials/host materials, the matrix materials/host materials of the formulae (eTMM1), (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d), (eTMM1e), (eTMM1f), (eTMM2), (eTMM2a), (eTMM3), (eTMM3a), (eTMM4) or (eTMM5) and their embodiments in table 3 that are described as preferred or compounds E1 to E41.

Very particularly preferred mixtures of the compounds of the formula (1) with the host materials of the formulae (eTMM1), (eTMM1a), (eTMM1 b), (eTMM1c), (eTMM1d), (eTMM1e), (eTMM1f), (eTMM2), (eTMM2a), (eTMM3), (eTMM3a), (eTMM4) or (eTMM5) for the device of the invention are obtained by combination of the compounds H1 to H12 with the compounds E1 to E41 as shown hereinafter in table 5. The first mixture M1, for example, is a combination of compound E1 with H1.

Table 5:

The concentration of the total of all host materials of the invention as described above or described as preferred in the mixture of the invention or in the light-emitting layer of the device of the invention is typically in the range from 5% by weight to 90% by weight, preferably in the range from 10% by weight to 85% by weight, more preferably in the range from 20% by weight to 85% by weight, even more preferably in the range from 30% by weight to 80% by weight, very especially preferably in the range from 20% by weight to 60% by weight and most preferably in the range from 30% by weight to 50% by weight, based on the overall mixture or based on the overall composition of the light-emitting layer. The concentration of the total of all host materials of the formulae (eTMM1), (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d), (eTMM1e), (eTMM1f), (eTMM2), (eTMM2a), (eTMM3), (eTMM3a), (eTMM4) or (eTMM5) as described above or described as preferred in the mixture of the invention or in the light-emitting layer of the device of the invention is typically in the range from 5% by weight to 90% by weight, preferably in the range from 10% by weight to 85% by weight, more preferably in the range from 20% by weight to 85% by weight, even more preferably in the range from 30% by weight to 80% by weight, very especially preferably in the range from 20% by weight to 60% by weight and most preferably in the range from 30% by weight to 50% by weight, based on the overall mixture or based on the overall composition of the light-emitting layer.

The present invention also relates to a mixture which, as well as the aforementioned host materials of the invention and the host material of at least one of the formulae (eTMM1), (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d), (eTMM1e), (eTMM1f), (eTMM2), (eTMM2a), (eTMM3), (eTMM3a), (eTMM4) and (eTMM5) as described above or described as preferred, also comprises at least one phosphorescent emitter.

The present invention relates further to a mixture selected from M1 to M492 with at least one phosphorescent emitter as described below.

The term “phosphorescent emitters” typically encompasses compounds where the light is emitted through a spin-forbidden transition from an excited state having higher spin multiplicity, i.e. a spin state > 1, for example through a transition from a triplet state or a state having an even higher spin quantum number, for example a quintet state. This is preferably understood to mean a transition from a triplet state.

Suitable phosphorescent emitters (= triplet 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, especially a metal having this atomic number. Preferred phosphorescence emitters used are compounds containing copper, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, iridium, palladium, platinum, silver, gold or europium, especially compounds containing iridium or platinum. In the context of the present invention, all luminescent compounds containing the abovementioned metals are regarded as phosphorescent emitters. 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.

Preferred phosphorescent emitters according to the present invention conform to the formulae (I), (II), (III), (IV) or (V)

where the symbols and indices for these formulae (I), (II), (III), (IV) and (V) are defined as follows:

R₁ is H or D, R2 is H, D, F, CN or a branched or linear alkyl group having 1 to 10 carbon atoms or a partly or fully deuterated branched or linear alkyl group having 1 to 10 carbon atoms or a cycloalkyl group which has 4 to 10 carbon atoms and may be partly or fully substituted by deuterium.

Preferred phosphorescent emitters according to the present invention conform to the formulae (VI), (VII) or (VIII)

where the symbols and indices for these formulae (VI), (VII) and (VIII) are defined as follows:

RI is H or D, R2 is H, D, F, CN or a branched or linear alkyl group having 1 to 10 carbon atoms or a partly or fully deuterated branched or linear alkyl group having 1 to 10 carbon atoms or a cycloalkyl group which has 4 to 10 carbon atoms and may be partly or fully substituted by deuterium.

Preferred phosphorescent emitters according to the present invention conform to the formula (IX)

where the symbols and indices for this formula (Illa) are defined as follows: n+m is 3, n is 1 or 2, m is 2 or 1,

X is the same or different at each instance and is N or CR,

R is the same or different at each instance and is H, D, F, CN or a branched or linear alkyl group having 1 to 10 carbon atoms or a partly or fully deuterated, branched or linear alkyl group having 1 to 10 carbon atoms or a cycloalkyl group having 4 to 7 carbon atoms, which may be partly or fully substituted by deuterium, or an aromatic heteroaromatic ring system which has 5 to 60 ring atoms and may be partly or fully substituted by deuterium.

The invention accordingly further provides an organic electroluminescent device as described above or described as preferred, characterized in that the light-emitting layer, as well as the host materials 1 and 2, comprises at least one phosphorescent emitter conforming to the formula (IX) as described above.

In emitters of the formula (IX), n is preferably 1 and m is preferably 2.

In emitters of the formula (IX), preferably, one X is selected from N and the other X are CR, or all X are the same or different at each instance and are CR.

In emitters of the formula (IX), at least one R is preferably different from H. In emitters of the formula (Illa), preferably two R are different from H and have one of the other definitions given above for the emitters of the formula (IX).

Preferred examples of phosphorescent emitters are described in WO2019/007867 on pages 120 to 126 in table 5, and on pages 127 to 129 in table 6. The emitters are incorporated into description by this reference.

Particularly preferred examples of phosphorescent emitters are listed in table 6 below.

In the mixtures of the invention or in the light-emitting layer of the device of the invention, any mixture selected from the sum of the mixtures M1 to M492 is preferably combined with a compound of of the formulae (I) to (IX) or a compound from table 6.

The light-emitting layer in the organic electroluminescent device of the invention, comprising at least one phosphorescent emitter, is preferably an infrared-emitting or yellow-, orange-, red-, green-, blue- or ultraviolet-emitting layer, more preferably a yellow- or green-emitting layer and most preferably a green-emitting layer.

A yellow-emitting layer is understood here to mean a layer having a photoluminescence maximum within the range from 540 to 570 nm. An orange-emitting layer is understood to mean a layer having a photoluminescence maximum within the range from 570 to 600 nm. A red-emitting layer is understood to mean a layer having a photoluminescence maximum within the range from 600 to 750 nm. A green-emitting layer is understood to mean a layer having a photoluminescence maximum within the range from 490 to 540 nm. A blue- emitting layer is understood to mean a layer having a photoluminescence maximum within the range from 440 to 490 nm. The photoluminescence maximum of the layer is determined here by measuring the photoluminescence spectrum of the layer having a layer thickness of 50 nm at room temperature, where the layer comprises the inventive combination of the host material 1 of the formulae (1) and of the host material 2 consisting of at least one of the formulae (eTMM1), (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d), (eTMM1e), (eTMM1f), (eTMM2), (eTMM2a), (eTMM3), (eTMM3a), (eTMM4) and (eTMM5), and the corresponding emitter. The photoluminescence spectrum of the layer is recorded, for example, with a commercial photoluminescence spectrometer.

The photoluminescence spectrum of the emitter chosen is generally measured in oxygen- free solution, 10'⁵ molar, at room temperature, a suitable solvent being any in which the chosen emitter dissolves in the concentration mentioned. Particularly suitable solvents are typically toluene or 2-methyl-THF, but also dichloromethane. Measurement is effected with a commercial photoluminescence spectrometer. The triplet energy T1 in eV is determined from the photoluminescence spectra of the emitters. First the peak maximum Plmax. (in nm) of the photoluminescence spectrum is determined. The peak maximum Plmax. (in nm) is then converted to eV by: E(T 1 in eV) = 1240 / E(T 1 in nm) = 12401 PLmax. (in nm).

Preferred phosphorescent emitters are accordingly yellow emitters, preferably of the formula (Illa), of the formulae (I) to (VIII) or from table 6, the triplet energy Ti of which is preferably ~2.3 eV to ~2.1 eV.

Preferred phosphorescent emitters are accordingly green emitters, preferably of the formula (Illa), of the formulae (I) to (VIII) or from table 6, the triplet energy Ti of which is preferably ~2.5 eV to ~2.3 eV.

Particularly preferred phosphorescent emitters are accordingly green emitters, preferably of the formula (Illa), of the formulae (I) to (VIII) or from table 6 as described above, the triplet energy Ti of which is preferably ~2.5 eV to ~2.3 eV.

Most preferably, green emitters, preferably of the formulae (I) to (IX) or from table 6, as described above, are selected for the mixture of the invention or emitting layer of the invention.

It is also possible for fluorescent emitters to be present in the light-emitting layer of the device of the invention or in the mixture of the invention.

Preferred fluorescent emitting compounds are selected from the class of the arylamines, where preferably at least one of the aromatic or heteroaromatic ring systems of the arylamine is a fused ring system, more preferably having at least 14 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 positions. 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 positions. Further preferred emitting compounds are indenofluoreneamines or -diamines, benzoindenofluoreneamines or - diamines, and dibenzoindenofluoreneamines 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. The light-emitting device or the mixture of the invention may additionally also comprise materials that exhibit TADF (thermally activated delayed fluorescence).

In a further preferred embodiment of the invention, the at least one light-emitting layer of the organic electroluminescent device may have three or four different matrix materials, preferably three different matrix materials. These corresponding mixed matrix systems may consist of the matrix materials described for the host material 1 and the host material 2, but they may also comprise, as a third or fourth matrix material, for example alongside a host material 1 or host material 2, wide-band-gap materials, bipolar host materials, electron transport materials (ETM) or hole transport materials (HTM).

Preferably, the mixed matrix system is optimized for an emitter of the formulae (I) to (IX), or for an emitter from table 6.

In one embodiment of the present invention, the mixture, aside from the constituents of the host material of the formula (1) and the host material 2 as described above or described with preference, does not comprise any further constituents, i.e. functional materials. These are material mixtures that are used as such for production of the light- emitting layer. These mixtures are also referred to as premix systems that are used as the sole material source in the vapor deposition of the host materials for the light-emitting layer and have a constant mixing ratio in the vapor deposition. In this way, it is possible in a simple and rapid manner to achieve the vapor deposition of a layer with homogeneous distribution of the components without the need for precise actuation of a multitude of material sources. In an alternative embodiment of the present invention, the mixture, aside from the constituents of the host material of the formula (1) and the host material 2, as described above or described with preference, also comprises a phosphorescent emitter, as described above. In the case of a suitable mixing ratio in the vapor deposition, this mixture may also be used as the sole material source.

Preference is given to premix systems consisting of two matrix materials, namely one compound of the formula (1) and one compound of one of the formulae (eTMM1), (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d), (eTMM1e), (eTMM1f), (eTMM2), (eTMM2a), (eTMM3), (eTMM3a), (eTMM4) and (eTMM5).

Preference is given to premix systems consisting of three matrix materials, namely one compound of the formulae (1) and two compounds of one of the formulae (eTMM1), (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d), (eTMM1e), (eTMM1f), (eTMM2), (eTMM2a), (eTMM3), (eTMM3a), (eTMM4) and (eTMM5).

The components or constituents of the light-emitting layer of the device of the invention may thus be processed by vapor deposition or from solution. The material combination of host materials 1 and 2, as described above or described as preferred, optionally with the phosphorescent emitter, as described above or described as preferred, are provided for that purpose in a formulation containing at least one solvent. Suitable formulations have been described above.

The light-emitting layer in the device of the invention, according to the preferred embodiments and the emitting compound, contains preferably between 99.9% and 1% by volume, further preferably between 99% and 10% by volume, especially preferably between 98% and 60% by volume, very especially preferably between 97% and 80% by volume, of matrix material composed of at least one compound of the formula (1) and at least one compound of one of the formulae ((eTMM1), (eTMM1a), (eTMM1b), (eTMM1c), (eTMM1d), (eTMM1e), (eTMM1f), (eTMM2), (eTMM2a), (eTMM3), (eTMM3a), (eTMM4) and (eTMM5) according to the preferred embodiments, based on the overall composition of emitter and matrix material. Correspondingly, the light-emitting layer in the device of the invention preferably contains between 0.1% and 99% by volume, further preferably between 1% and 90% by volume, more preferably between 2% and 40% by volume, most preferably between 3% and 20% by volume, of the emitter based on the overall composition of the light-emitting layer composed of emitter and matrix material. If the compounds are processed from solution, preference is given to using the corresponding amounts in % by weight rather than the above-specified amounts in % by volume.

The present invention also relates to an organic electroluminescent device as described above or described as preferred, wherein the organic layer comprises a hole injection layer (HIL) and/or a hole transport layer (HTL), the hole-injecting material and hole- transporting material of which belongs to the class of arylamines.

The sequence of layers in the organic electroluminescent device of the invention is preferably as follows: anode / hole injection layer / hole transport layer / emitting layer / hole blocker layer / electron transport layer / electron injection layer / cathode.

This sequence of the layers is a preferred sequence.

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.

Materials used for the electron transport layer may be any materials as used according to the prior art as electron transport materials in the electron transport layer. Especially suitable are aluminum complexes, for example Alq₃, zirconium complexes, for example Zrq₄, 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.

Suitable cathodes of the device of the invention 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, 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, Li₂O, 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.

The organic electroluminescent device of the invention, in the course of production, is appropriately (according to the application) structured, contact-connected and finally sealed, since the lifetime of the devices of the invention is shortened in the presence of water and/or air.

The production of the device of the invention is not restricted here. It is possible that one or more organic layers, including the light-emitting layer, are coated by a sublimation method. In this case, the materials are applied by vapor 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.

The organic electroluminescent device of the invention is preferably characterized in that one or more layers are coated by the OVPD (organic vapor 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 vapor 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).

The organic electroluminescent device of the invention is further preferably characterized in that one or more organic layers comprising the composition of the invention 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 host materials 1 and 2 and phosphorescent emitters are needed. Processing from solution has the advantage that, for example, the light-emitting layer can be applied in a very simple and inexpensive manner. This technique is especially suitable for the mass production of organic electroluminescent devices.

In addition, hybrid methods are possible, in which, for example, one or more layers are applied from solution and one or more further layers are applied by vapor deposition.

These methods are known in general terms to those skilled in the art and can be applied to organic electroluminescent devices.

The invention therefore further provides a process for producing the organic electroluminescent device of the invention as described above or described as preferred, characterized in that the organic layer, preferably the light-emitting layer, the hole injection layer and/or hole transport layer, is applied by gas phase deposition, especially by a sublimation method and/or by an OVPD (organic vapor phase deposition) method and/or with the aid of a carrier gas sublimation, or from solution, especially by spin-coating or by a printing method.

In the case of production by means of gas phase deposition, there are in principle two ways in which the organic layer, preferably the light-emitting layer, of the invention can be applied or vapor-deposited onto any substrate or the prior layer. Firstly, the materials used can each be initially charged in a material source and ultimately evaporated from the different material sources ("co-evaporation"). Secondly, the various materials can be premixed (premix systems) and the mixture can be initially charged in a single material source from which it is ultimately evaporated ("premix evaporation"). In this way, it is possible in a simple and rapid manner to achieve the vapor deposition of the light-emitting layer with homogeneous distribution of the components without the need for precise actuation of a multitude of material sources.

The following methods are possible:

A process for producing the organic electroluminescent device of the invention as described above or described as preferred, characterized in that the organic layer, preferably the light- emitting layer, the electron transport layer and/or hole blocker layer, is applied by gas phase deposition, especially by a sublimation method and/or by an OVPD (organic vapor phase deposition) method and/or with the aid of a carrier gas sublimation, or from solution, especially by spin-coating or by a printing method.

A process for producing the organic electroluminescent device of the invention, as described above or described as preferred, characterized in that the light-emitting layer of the organic layer is applied by gas phase deposition, wherein the at least one compound of the formulae (1) is deposited from the gas phase together with the further materials that form the light-emitting layer, successively or simultaneously from at least two material sources.

A process for producing the device of the invention, characterized in that the light-emitting layer of the organic layer is applied by gas phase deposition, wherein the at least one compound of the formulae (1) is deposited from the gas phase together with at least one further matrix material as premix, successively or simultaneously with the light-emitting materials selected from the group of the phosphorescent emitters, fluorescent emitters and/or emitters that exhibit TADF (thermally activated delayed fluorescence).

The electronic devices of the invention, especially organic electroluminescent devices, are notable for one or more of the following surprising advantages over the prior art:

1. Electronic devices, especially organic electroluminescent devices, comprising compounds of formula (1) or the preferred embodiments recited above and hereinafter, especially as matrix material or as hole-conducting materials, have a very good lifetime. In this context, these compounds especially bring about low roll- off, i.e. a small drop in power efficiency of the device at high luminances.

2. Electronic devices, especially organic electroluminescent devices, comprising compounds of formula (1) or the preferred embodiments recited above and hereinafter, or as hole-conducting materials and/or matrix materials, have excellent efficiency. In this context, compounds of the invention having structures of formula (1) or the preferred embodiments recited above and hereinafter bring about a low operating voltage when used in electronic devices.

3. The inventive compounds of the formula (1) or the preferred embodiments recited above and hereinafter exhibit very high stability and lifetime.

4. With compounds of the formula (1) or the preferred embodiments recited above and hereinafter, it is possible to avoid the formation of optical loss channels in electronic devices, especially organic electroluminescent devices. As a result, these devices feature a high PL efficiency and hence high EL efficiency of emitters, and excellent energy transmission of the matrices to dopants.

5. The use of compounds of the formula (1) or the preferred embodiments recited above and hereinafter in layers of electronic devices, especially organic electroluminescent devices, leads to high mobility of the electron conductor structures.

6. Compounds of the formula (1) or the preferred embodiments recited above and hereinafter have excellent glass film formation.

7. Compounds of the formula (1) or the preferred embodiments recited above and hereinafter form very good films from solutions.

8. The compounds of the formula (1) or the preferred embodiments recited above and hereinafter have a triplet level Ti which may, for example, be in the range of

2.00 eV-2.90 eV.

These abovementioned advantages are not accompanied by an inordinately high deterioration in the further electronic properties.

It should be pointed out that variations of the embodiments described in the present invention are covered by the scope of this invention. Any feature disclosed in the present invention may, unless this is explicitly ruled out, be exchanged for alternative features which serve the same purpose or an equivalent or similar purpose. Any feature disclosed in the present invention, unless stated otherwise, should therefore be considered as an example from a generic series or as an equivalent or similar feature.

All features of the present invention may be combined with one another in any manner, unless particular features and/or steps are mutually exclusive. This is especially true of preferred features of the present invention. Equally, features of non-essential combinations may be used separately (and not in combination).

The technical teaching disclosed with the present invention may be abstracted and combined with other examples.

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

Synthesis examples

The syntheses which follow, unless stated otherwise, are conducted under a protective gas atmosphere in dried solvents. The solvents and reagents can be purchased, for example, from Sigma-ALDRICH or ABCR. The respective figures in square brackets or the numbers quoted for individual compounds relate to the CAS numbers of the compounds known from the literature. In the case of compounds that can have multiple enantiomeric, diastereomeric or tautomeric forms, one form is shown in a representative manner.

A: Literature known compounds LC:

B: Synthesis of synthons S:

Preparation according to S. H. Kim et al., J. Mat. Chem., 2011 , 21(25), 9139.

Use of 40.6 g (100 mmol) 3, 6-dibromo-9-(phenyl-2, 3, 4,5, 6-d₅)-9H-carbazole [1354054-12- 8], Yield: 35.1 g (70 mmol). Purity: app. 98 % by ¹H-NMR.

The following compounds can be prepared analogously:

Example S100:

Preparation according to P. Gong et al., Tetrahedron Letters, 2016, 57, 1468.

Use of 16.5 g (50 mmol) B,B'-(9-Phenyl-9H -carbazole-3,6-diyl)bisboronic acid [1135916- 40-3] and 26.3 g (130 mmol) 1-bromo-2-nitrobenzene [577-19-5], Separation of the product from the isomer mixture by automated flash chromatography (CombiFlash Torrent, A. Semrau). Yield: 7.2 g (17 mmol) 34 %. Purity: app. 99 % by ¹H-NMR.

The following compounds can be prepared analogously:

C: Synthesis of the inventive Materials C:

Example C1

A stirred suspension of 33.2 g (100 mmol) of LS1 in 1000 ml of diethyl ether is treated dropwise with 80 ml of n-butyllithium, 2.5 molar in n-hexanes at room temperature. The reaction mixture is stirred 2 h at room temperature. A mixture of 22.2 ml (105 mmol) of dichlorodiphenylsilane [80-10-4] and 200 ml of diethylether is added dropwise upon which a mild exothermic reaction occurs. After completion of addition the mixture is heated under reflux for 6 h. The diethyl ether is removed in vacuum, the residue is suspended in 500 ml of dichloromethane, the suspension is filtered over a bed of basic alumina (activity 1) and rinsed with addition 200 ml of dichloromethane. The filtrate concentrated in vacuum to obtain the raw product. Further purification of the raw product is achieved by automated flash chromatography (CombiFlash Torrent, A. Semrau) and hot extraction crystallization (usual org. solvents, preferably mixtures of dichloromethane / acetonitrile 1:3 bis 3:1 vv) and final fractionated sublimation in high vacuum. Yield: 31.9 g (62 mmol)

62 %. Purity: > 99.9 % by HPLC.

Example C2:

5 Preparation according to procedure C1, instead of dichlorodiphenylsilane 5.7 ml

(50 mmol) of tetrachlorosilane [10026-07-4] is used. Yield: 20.5 g (30 mmol) 60 %. Purity:

> 99.9 % by HPLC.

The following compounds can be prepared analogously:

Example: Production of the OLEDs

Vacuum-Processed Devices: OLEDs of the invention are produced by a general method according to WO 2004/058911, which is adapted to the circumstances described here (variation in layer thickness, materials used).

In the examples which follow, the results for various OLEDs are presented. Cleaned glass plaques (cleaning in Miele laboratory glass washer, Merck Extran detergent) coated with structured ITO (indium tin oxide) of thickness 50 nm are pretreated with UV ozone for 25 minutes (PR-100 UV ozone generator from UVP) and, within 30 min, for improved processing, coated with 20 nm of PEDOT:PSS (poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate), purchased as CLEVIOS™ P VP Al 4083 from Heraeus Precious Metals GmbH Deutschland, spun on from aqueous solution) and then baked at 180° C. for 10 min. These coated glass plaques form the substrates to which the OLEDs are applied.

The OLEDs basically have the following layer structure: substrate hole injection layer (HIL), consisting of HTM1 doped with 5% NDP-9 (commercially available from Novaled), 20 nm hole transport layer (HTL) electron blocking layer (EBL) emission layer (EML) hole blocking layer (HBL) electron transport layer (ETL), consisting of a mixture of ETM1:ETM2 (50%:50%), 30 nm electron injection (EIL) consisting of ETM2, 1 nm cathode consisting of aluminum, 100 nm

All the materials are applied by thermal vapor deposition in a vacuum chamber. In this case, the emission layer always consists of at least one matrix material (host material) and an emitting dopant (emitter) which is added to the matrix material(s) in a particular proportion by volume by co-evaporation. Details given in such a form as E41:H2:lr (55%:35%:10%) mean here that the material E41 is present in the layer in a proportion by volume of 55%, H2 in a proportion by volume of 35% and Ir in a proportion by volume of 10%.

The exact structure of the OLEDs can be found in Table 7. The materials used for production of the OLEDs are shown in Table 9.

The OLEDs are characterized in a standard manner. For this purpose, the electroluminescence spectra, the current efficiency (measured in cd/A), the power efficiency (measured in Im/W) and the external quantum efficiency (EQE, measured in percent) as a function of luminance, calculated from current-voltage-luminance characteristics (IUL characteristics) assuming Lambertian emission characteristics.

One use of the compounds of the invention is as host material in Phosphorescent OLEDs.

The results for the OLEDs are collected in Table 8.

Table 8: Results of Phosphorescent PLED devices

Table 9: materials used for production of the OLEDs

Claims

Patent Claims

1. Compound represented by a Formula (1):

Formula (1) where the groups and indices that occur are as follows:

X¹¹ is CR¹¹ or N, X¹² is CR¹² or N, X¹³ is CR¹³ or N, X¹⁴ is CR¹⁴ or N, X¹⁵ is CR¹⁵ or N, X¹⁶ is CR¹⁶ or N, X¹⁷ is CR¹⁷ or N, X¹⁸ is CR¹⁸ or N, X¹⁹ is CR¹⁹ or N, and X²⁰ is CR²⁰ or N;

R¹¹ to R²⁰ stand on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CHO, CN, N(R³)₂, C(=O)R³, P(=O)(R³)₂, S(=O)R³, S(=O)₂R³, NO₂, Si(R³)₃, Ge(R³)₃, B(R³)₂, B(OR³)₂, OSO₂R³, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 40 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 40 C atoms, each of which may be substituted by one or more radicals R³, where in each case one or more non-adjacent CH₂ groups may be replaced by R³C=CR³, C=C, Si(R³)₂, Ge(R³)₂, Sn(R³)₂, C=O, C=S, C=Se, P(=O)(R³), SO, SO₂, O, S or CONR³ and where one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO₂, an aromatic or heteroaromatic ring system having 5 to 60 ring atoms, which may in each case be substituted by one or more radicals R³, or an aryloxy or heteroaryloxy group having 5 to 60 ring atoms, which may be substituted by one or more radicals R³; wherein two of radicals R¹¹ to R²⁰ may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R³;

R²¹ and R²² stand on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CHO, CN, N(R⁴)₂, C(=O)R⁴, P(=O)(R⁴)₂, S(=O)R⁴, S(=O)₂R⁴, NO₂, Si(R⁴)₃, Ge(R⁴)₃, B(OR⁴)₂, OSO₂R⁴, a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 40 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 40 C atoms, each of which may be substituted by one or more radicals R⁴, where in each case one or more non-adjacent CH₂ groups may be replaced by R⁴C=CR⁴, C=C, Si(R⁴)₂, Ge(R⁴)₂, Sn(R⁴)₂, C=O, C=S, C=Se, P(=O)(R⁴), SO, SO₂, O, S or CONR⁴ and where one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO₂, an aromatic or heteroaromatic ring system having 5 to 60 ring atoms, which may in each case be substituted by one or more radicals R⁴, or an aryloxy or heteroaryloxy group having 5 to 60 ring atoms, which may be substituted by one or more radicals R⁴; wherein R²¹ and R²² may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R⁴;

R³ and R⁴ stand on each occurrence, identically or differently, for H, D, F, Cl, Br, I, CHO, CN, N(Ar)₂, C(=O)Ar, P(=O)(Ar)₂, S(=O)Ar, S(=O)₂Ar, NO₂, Si(R')₃, Ge(R')₃, B(OR')₂, OSO₂R , a straight-chain alkyl, alkoxy or thioalkyl group having 1 to 40 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl group having 3 to 40 C atoms, each of which may be substituted by one or more radicals R', where in each case one or more non-adjacent CH₂ groups may be replaced by R'C=CR', C=C, Si(R')₂, Ge(R')₂, Sn(R')₂, C=O, C=S, C=Se, P(=O)(R'), SO, SO₂, O, S or CONR' and where one or more H atoms may be replaced by D, F, Cl, Br, I, CN or NO₂, an aromatic or heteroaromatic ring system having 5 to 60 ring atoms, which may in each case be substituted by one or more radicals R', or an aryloxy or heteroaryloxy group having 5 to 60 ring atoms, which may be substituted by one or more radicals R'; wherein R³ and R⁴ may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R';

2. Compound according to Claim 1 , characterized in that the compound represented by at least one of Formulae 1-1 to 1-3:

1-3 wherein in Formulae 1-1 to 1-3,

Z²⁰, X¹¹ to X²⁰ have the definition given in Claim 1 ;

X³ stands on each occurrence, identically or differently, CR³ or N; and R³ has the definition given in Claim 1.

3. Compound according to Claim 1 or 2, characterized in that the group is represented by at least one of Formulae 2-1 to 2-3:

wherein in Formulae 2-1 to 2-3,

X¹³ to X¹⁸ have the definition given in Claim 1 ;

R³¹ and R³²are each independently refer to the definition of R³;

X³ stands on each occurrence, identically or differently, CR³ or N; and wherein two adjacent substituents R³, R³¹ and R³² may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R',

R³ and R' have the definition given in Claim 1 ; and

*” stands on each occurrence, a binding site to adjacent atom.

4. Compound according to one or more of claims 1 to 3, characterized in that Z²⁰ is represented by at least one of Formulae 3-1 to 3-7:

wherein in Formulae 3-1 to 3-7,

Z is C, Si or Ge,

Z⁴⁰ is a single bond, N(R⁴⁵), S, O, C(R⁴⁵)(R⁴⁶), C(R⁴⁵)=C(R⁴⁶), Si(R⁴⁵)(R⁴⁶) or

Ge(R⁴⁵)(R⁴⁶);

Y⁴¹ is NR⁴⁷ or O, Y⁴² is NR⁴⁸ or O;

R⁴¹ to R⁴⁸ are each independently refer to the definition of R⁴;

X⁴ stands on each occurrence, identically or differently, OR⁴ or N; wherein R²¹ and R²² may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R⁴; wherein two adjacent substituents R⁴ and R⁴¹ to R⁴⁸ may form a mono- or polycyclic, aliphatic ring system or aromatic ring system, which may be substituted by one or more radicals R',

R²¹, R²², R⁴ and R' have the definition given in Claim 1 ; and

*, *' and stand on each occurrence, a binding site to adjacent atom.

5. Compound according to one or more of claims 1 to 4, characterized in that R²¹ and R²² are either identical or different from one another.

6. Compound according to one or more of claims 1 to 5, characterized in that the compound satisfies at least one of Conditions 1 to 5:

X¹¹ and X²⁰ is identical

X¹² and X¹⁹ is identical

X¹³ and X¹⁸ is identical

X¹⁴ and X¹⁷ is identical

X¹⁵ and X¹⁶ is identical.

7. Compound according to one or more of claims 1 to 6, characterized in that compound comprises at least one of deuterium.

8. Compound according to one or more of claims 1 to 7, characterized in that R¹¹ to R²⁰ are selected, identically or differently at each occurrence, from H, D, F, CN, Si(R³)₃, N(R³)₂, B(R³)₂, straight-chain alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl groups having 3 to 20 C atoms, each of which may be substituted by one or more radicals R³, where in each case one or more non-adjacent CH₂ groups may be replaced by R³C=CR³ or C=C; aromatic ring systems having 6 to 40 ring atoms and heteroaromatic ring systems having 5 to 40 ring atoms, which may in each case be substituted by one or more radicals R³; or an aryloxy group having 6 to 40 ring atoms, which may in each case be substituted by one or more radicals R³, R³ has the definition given in Claim 1.

9. Compound according to one or more of claims 1 to 8, characterized in that R²¹ and R²² are selected, identically or differently at each occurrence, from H, D, F, CN, Si(R⁴)₃, N(R⁴)₂, straight-chain alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl groups having 3 to 20 C atoms, each of which may be substituted by one or more radicals R⁴, where in each case one or more non-adjacent CH₂ groups may be replaced by R⁴C=CR⁴ or C=C; aromatic ring systems having 6 to 40 ring atoms and heteroaromatic ring systems having 5 to 40 ring atoms, which may in each case be sub- stituted by one or more radicals R⁴; or an aryloxy group having 6 to 40 ring atoms, which may in each case be substituted by one or more radicals R⁴, R⁴ has the definition given in Claim 1.

10. Compound according to one or more of claims 1 to 9, characterized in that R³ and R⁴ are selected, identically or differently at each occurrence, from H, D, F, CN, Si(R')₃, N(R')₂, straight-chain alkyl, alkoxy or thioalkyl group having 1 to 20 C atoms or branched or cyclic alkyl, alkoxy or thioalkyl groups having 3 to 20 C atoms, each of which may be substituted by one or more radicals R', where in each case one or more non-adjacent CH₂ groups may be replaced by R'C=CR' or C=C; aromatic ring systems having 6 to 40 ring atoms and heteroaromatic ring systems having 5 to 40 ring atoms, which may in each case be sub- stituted by one or more radicals R'; or an aryloxy group having 6 to 40 ring atoms, which may in each case be substituted by one or more radicals R', R' has the definition given in Claim 1.

11. Mixture comprising at least one compound according to any one of claims 1 to 10 and at least one further compound and/or at least one solvent, wherein the further compound selected from the group consisting of fluorescent emitters, phosphorescent emitters, TADF emitters, host materials, matrix materials, electron transport materials, electron injection materials, hole conductor materials, hole injection materials, n-dopants, wide band gap materials, electron blocking materials and hole blocking materials.

12. Mixture comprising at least one compound according to any one of claims 1 to 10 and at least one compound of formulae (eTMM1), (eTMM2), (eTMM3), (eTMM4) or (eTMM5)

where the symbols and indices used are as follows:

V² is O or S;

R⁷ is the same or different at each instance and is H, D, F, Cl, Br, I, N(R⁸)₂, CN, NO₂, OR⁸, SR⁸, Si(R⁸)₃, B(OR⁸)₂, C(=O)R⁸, P(=O)(R⁸)₂, S(=O)R⁸, S(=O)₂ R⁸, OSO₂R⁸, 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, where the alkyl, alkenyl or alkynyl group may in each case be substituted by one or more R⁸ radicals and where one or more nonadjacent CH₂ groups may be replaced by Si(R⁸)₂, C=O, NR⁸, O, S or CONR⁸, or an aromatic or heteroaromatic ring system which has 5 to 40 ring atoms and may be substituted in each case by one or more R⁸ radicals; at the same time, two or more R⁷ radicals together may form an aromatic, heteroaromatic, aliphatic or heteroaliphatic ring system;

13. Electronic device comprising at least one compound according to one or more of Claims 1 to 10 or mixture according to Claim 11 or 12.

14. Electronic device according to Claim 13, characterized in that it is an organic electroluminescent device and comprises an anode, cathode and at least one emitting layer, and in that the compound is present in a hole-transporting layer or in an emitting layer of the device.

15. Use of a compound as claimed in one or more of Claims 1 to 10 in an electronic device.