ORGANIC ELECTROLUMINESCENT DEVICE

Information

  • Patent Application
  • 20230397495
  • Publication Number
    20230397495
  • Date Filed
    October 25, 2021
    2 years ago
  • Date Published
    December 07, 2023
    5 months ago
Abstract
The present invention relates to an organic electroluminescent device comprising a light-emitting layer comprising an electron-transporting host material and a hole-transporting host material, and to a formulation comprising a mixture of the host materials and to a mixture comprising the host materials. The electron-transporting host material corresponds to a compound of the formula (1) comprising diazadibenzofuran or diazadibenzothiophene units. The hole-transporting host material corresponds to a compound of the formula (2) from the class of the biscarbazoles or the derivatives thereof.
Description
SUBJECT-MATTER OF THE INVENTION

The present invention relates to an organic electroluminescent device comprising a light-emitting layer comprising an electron-transporting host material and a hole-transporting host material, and to a formulation comprising a mixture of the host materials and to a mixture comprising the host materials. The electron-transporting host material corresponds to a compound of the formula (1) comprising diazadibenzofuran or diazadibenzothiophene units. The hole-transporting host material corresponds to a compound of the formula (2) from the class of the biscarbazoles or the derivatives thereof.


BACKGROUND OF THE INVENTION

The structure of organic electroluminescent devices (e.g. OLEDs—organic light-emitting diodes or OLECs—organic light-emitting electrochemical cells) in which organic semiconductors are used as functional materials has long been known. Emitting materials used here, aside from fluorescent emitters, are increasingly organometallic complexes which exhibit phosphorescence rather than fluorescence. In general terms, however, there is still a need for improvement in OLEDs, especially also in OLEDs which exhibit triplet emission (phosphorescence), for example with regard to efficiency, operating voltage and lifetime.


The properties of organic electroluminescent devices are not only determined by the emitters used. Also of particular significance here are especially the other materials used, such as host and matrix materials, hole blocker materials, electron transport materials, hole transport materials and electron or exciton blocker materials, and among these especially the host or matrix materials. Improvements to these materials can lead to distinct improvements to electroluminescent devices.


Host materials for use in organic electronic devices are well known to the person skilled in the art. The term “matrix material” is also frequently used in the prior art when what is meant is a host material for phosphorescent emitters. This use of the term is also applicable to the present invention. In the meantime, a multitude of host materials has been developed both for fluorescent and for phosphorescent electronic devices.


A further means of improving the performance data of electronic devices, especially of organic electroluminescent devices, is to use combinations of two or more materials, especially host materials or matrix materials.


U.S. Pat. No. 6,392,250 B1 discloses the use of a mixture consisting of an electron transport material, a hole transport material and a fluorescent emitter in the emission layer of an OLED. With the aid of this mixture, it was possible to improve the lifetime of the OLED compared to the prior art.


U.S. Pat. No. 6,803,720 B1 discloses the use of a mixture comprising a phosphorescent emitter and a hole transport material and an electron transport material in the emission layer of an OLED. Both the hole transport material and the electron transport material are small organic molecules.


WO2015169412 describes specific azadibenzofuran compounds or azadibenzothiophene compounds as host material for organic electroluminescent devices.


WO2015105315 and WO2015105316 disclose heterocycles comprising two nitrogen atoms and the use thereof in organic electroluminescent devices as a host material, optionally in combination with a further host material.


US2016013421 discloses benzothienopyrimidine compounds and the use thereof in an organic electroluminescent device as a host material.


US2016072078 describes electron-transporting host materials comprising carbazole units.


US2017200903 describes diazadibenzofuran compounds and diazadibenzothiophene compounds and the use thereof in an organic electroluminescent device, in particular as an electron transport material.


KR20160046077 and KR20160046078 describe an organic light-emitting device comprising a light-emitting layer comprising specific emitters in combination with various host materials.


KR20170113320 disclose specifically substituted dibenzofuran compounds and the use thereof as host material together with a biscarbazole in an organic electroluminescent device.


WO17109637 describes benzothienopyrimidine compounds and benzofuropyrimidine compounds and the use thereof in an organic electroluminescent device as a host material, wherein the benzothienopyrimidine compounds and benzofuropyrimidine compounds each bear two substituents comprising a furan, thiophene or pyrrole unit.


WO17186760 discloses diazacarbazole compounds and the use thereof in an organic electroluminescent device as a host material, electron transport material and hole blocker material.


WO18060218 discloses diazadibenzofuran compounds and diazadibenzothiophene compounds and the use thereof in an organic electroluminescent device, wherein the benzothienopyrimidine compounds and benzofuropyrimidine compounds each bear at least one substituent comprising an N-bonded carbazole unit.


KR20180010165 describes diazadibenzofuran compounds and diazadibenzothiophene compounds and the use thereof in an organic electroluminescent device.


WO18060307 describes diazadibenzofuran compounds and diazadibenzothiophene compounds and the use thereof in an organic electroluminescent device.


WO18234932, WO19059577, WO19229583 and WO19229584 describe diazadibenzofuran and diazadibenzothiophene derivatives which may be used as host materials in an electroluminescent device.


US2020161564 describes diazadibenzofuran compounds and diazadibenzothiophene compounds and the use thereof in an organic electroluminescent device.


US20200010476 disclose heterocyclic compounds, and describe the use thereof in organic electroluminescent devices.


WO20067657 describes a composition of materials and the use thereof in optoelectronic devices.


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 organic electroluminescent device.


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


SUMMARY OF THE INVENTION

It has now been found that this problem is solved, and the disadvantages from the prior art are eliminated, by the combination of at least one compound of the formula (1) as first host material and at least one hole-transporting compound of the formula (2) as second host material in a light-emitting layer of an organic electroluminescent device. The use of such a material combination for production of the light-emitting layer in an organic electroluminescent device leads to very good properties of these devices, especially with regard to lifetime, especially with equal or improved efficiency and/or operating voltage.


The advantages are especially also manifested in the presence of a light-emitting component in the emission layer, especially in the case of combination with emitters of the formula (3) or emitters of the formulae (I) to (VIII) at concentrations between 2% and 15% by weight or in combination with monoamines of formula (4) in the hole injection layer and/or hole transport layer.


The present invention therefore first provides an organic electroluminescent device comprising an anode, a cathode and at least one organic layer containing at least one light-emitting layer, wherein the at least one light-emitting layer contains at least one compound of the formula (1) as host material 1 and at least one compound of the formula (2) as host material 2




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    • where the symbols and indices used are as follows:

    • ring A1 in formula (1) conforms to the formula (1A)







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    • V is O or S;

    • V1 is O, S, C(R1)2 or N-A;

    • V2 is O or S;

    • Y is the same or different at each instance and is independently CH, CR or CA, or two adjacent Y groups together form a group of the formula (1B)







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    • and the remaining Y groups are independently CH or CR, where V3 is O, S, C(R1)2 or N-A and the dotted bonds show the linkage of this group to the remainder of the formula (1);

    • Rx is L1-R*;

    • Ry is L2-R*;

    • R* independently at each instance is an aromatic or heteroaromatic ring system which has 6 to 14 ring atoms and may be substituted by one or more R radicals;

    • L, L1, L2 are each independently a bond or a phenylene group which may each be substituted by one or more R radicals;

    • A is the same or different at each instance and is an aromatic or heteroaromatic ring system which has 6 to 30 ring atoms and may be substituted by one or more R radicals;

    • n is 0, 1, 2, 3 or 4;

    • m is 0, 1, 2 or 3;

    • R # is D or an aryl group which has 6 to 12 carbon atoms and may be substituted by one or more R radicals;

    • R1 is the same or different at each instance and is an alkyl group having 1 to 20 carbon atoms, phenyl which may be substituted by one or more R radicals, or the two R1 radicals together with the carbon atom to which they bind form a spiro compound;

    • R is the same or different at each instance and is 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 nonadjacent CH2 groups may be replaced by R2C═CR2, O or S and where one or more hydrogen atoms may be replaced by D, F, or CN;

    • R2 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 one or more nonadjacent CH2 groups may be replaced by O or S and where one or more hydrogen atoms may be replaced by D, F, or CN;

    • K, M are each independently an unsubstituted or partly or fully deuterated or R*-monosubstituted aromatic ring system having 6 to 40 ring atoms when x and y are 0 and when x1 and y1 are 0, or

    • K, M each independently together with X or X1 form a heteroaromatic ring system having 14 to 40 ring atoms when the value of x, x1, y and/or y1 is 1;

    • x, x1 at each instance are each independently 0 or 1;

    • y, y1 at each instance are each independently 0 or 1;

    • X and X1 at each instance are each independently a bond or C(R+)2;

    • R0 at each instance is independently an unsubstituted or partly or fully deuterated aromatic ring system having 6 to 18 carbon atoms;

    • R+ at each instance is independently a straight-chain or branched alkyl group having 1 to 4 carbon atoms and

    • c, d, e and f are independently 0 or 1.





The invention further provides a process for producing the organic electroluminescent devices and mixtures comprising at least one compound of the formula (1) and at least one compound of the formula (2), specific material combinations and formulations that contain such mixtures or material combinations. The corresponding preferred embodiments as described hereinafter likewise form part of the subject-matter of the present invention. The surprising and advantageous effects are achieved through specific selection of the compounds of the formula (1) and the compounds of the formula (2). The surprising and advantageous effects are achieved through specific selection of the compounds of the formula (1) and the compounds of the formula (2), preferably together with specific emitters in the light-emitting layer and with specific monoamines in the hole injection layer and/or hole transport layer.







DETAILED DESCRIPTION OF THE INVENTION

The organic electroluminescent 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 that comprises the light-emitting layer comprising the material combination of at least one compound of the formula (1) and at least one compound of the formula (2), as described or described above or hereinafter, preferably comprises, in addition to this light-emitting layer (EML), a hole injection layer (HIL), a hole transport layer (HTL), an electron transport layer (ETL), an electron injection layer (EIL) and/or a hole blocker layer (HBL). It is also possible for the device of the invention to include multiple layers from this group selected from EML, HIL, HTL, ETL, EIL and HBL.


However, the device may also comprise inorganic materials or else layers formed entirely from inorganic materials.


It is preferable when the organic layer of the device of the invention comprises a hole injection layer and/or the hole transport layer wherein the hole-injecting material and hole-transporting material is a monoamine that does not contain a carbazole unit. A suitable selection of monoamine compounds and preferred monoamines is described hereinbelow.


It is preferable when the light-emitting layer comprising at least one compound of the formula (1) and at least one compound of the formula (2) is a phosphorescent layer which is characterized in that it comprises, in addition to the host material combination of compounds of the formula (1) and formula (2), as described above, at least one phosphorescent emitter. A suitable selection of emitters and preferred emitters is described hereinafter.


An aryl group in the context of this invention contains 6 to 40 aromatic ring atoms, preferably carbon atoms. A heteroaryl group in the context of this invention contains 5 to 40 aromatic 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 or phenanthryl, 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 radicals R, where the substituent R is described below.


An aromatic ring system in the context of this invention contains 6 to 40 ring atoms. The aromatic ring system also includes aryl groups as described above.


A heteroaromatic ring system in the context of this invention contains 5 to 40 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 5-40 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- or trans-indenofluorene, cis- or trans-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.


An aromatic ring system having 6 to 18 carbon atoms as ring atoms is preferably selected from phenyl, 1,2-biphenyl, 1,3-biphenyl, 1,4-biphenyl, fluorenyl, naphthyl, phenanthryl and triphenylenyl, which may be substituted by one or more R radicals, where the substituent R is described hereinafter.


A preferred heteroaromatic ring system having 6 to 18 ring atoms is preferably selected from dibenzofuranyl and dibenzothiophenyl, which may be substituted by one or more R radicals, where the substituent R is described hereinafter.


The abbreviation A is the same or different at each instance and independently denotes an aromatic or heteroaromatic ring system which has 6 to 30 carbon atoms and may be substituted by one or more R radicals, where the R radical is defined as described above or hereinafter.


A cyclic alkyl 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, branched or cyclic C1- to C20-alkyl group 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.


When the host materials of the light-emitting layer comprising at least one compound of the formula (1) as described above or described as preferred hereinafter and at least one compound of the formula (2) as described above or described hereinafter are used for a phosphorescent emitter, it is preferable when the triplet energy thereof is not significantly less than the triplet energy of the phosphorescent emitter. In respect of the triplet level, it is preferably the case that T1(emitter)−T1(matrix)≤0.2 eV, more preferably ≤0.15 eV, most preferably ≤0.1 eV. T1(matrix) here is the triplet level of the matrix material in the emission layer, this condition being applicable to each of the two matrix materials, and T1(emitter) is the triplet level of the phosphorescent emitter. If the emission layer contains more than two matrix materials, the abovementioned relationship is preferably also applicable to every further matrix material.


There follows a description of the host material 1 and its preferred embodiments that is/are present in the device of the invention. The preferred embodiments of the host material 1 of the formula (1) are also applicable to the mixture and/or formulation of the invention.


In compounds of the formula (1), the attachment of the diaza group is possible in any of positions 1, 2, 3 and 4 on the central heterocycle. Preference is given to the attachment of the diaza group in position 1 on the central heterocycle.


A preferred embodiment of the compounds of the formula (1) is therefore compounds of the formula (1a):




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where the symbols Y, V, V1, R #, m, Rx, Ry, L and ring A1 used have a definition given above or specified as preferred hereinafter.


The invention further provides the organic electroluminescent device as described above, wherein the host material 1 conforms to the formula (1 a) as described above.


In compounds of the formula (1) or (1a), V1 is O, S, C(R1)2 or N-A, where R1 and A have a definition given above or specified as preferred hereinafter.


A preferred embodiment of the compounds of the formulae (1) and (1a) is therefore compounds in which V1 is NA, which are described by the formula (1b),




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where the symbols Y, V, R #, m, Rx, Ry, L and ring A1 used have a definition given above or specified as preferred hereinafter.


A preferred embodiment of the compounds of the formulae (1) and (1a) is therefore compounds in which V1 is O, which are described by the formula (1c),




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where the symbols Y, V, R #, m, Rx, Ry, L and ring A1 used have a definition given above or specified as preferred hereinafter.


A preferred embodiment of the compounds of the formulae (1) and (1a) is therefore compounds in which V1 is S, which are described by the formula (1d),




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where the symbols Y, V, R #, m, Rx, Ry, L and ring A1 used have a definition given above or specified as preferred hereinafter.


A preferred embodiment of the compounds of the formulae (1) and (1a) is therefore compounds in which V1 is C(R1)2, which are described by the formula (1e),




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where the symbols Y, V, R #, m, Rx, Ry, L and ring A1 used have a definition given above or specified as preferred hereinafter.


In compounds of the formulae (1), (1a) and (1b), Y at each instance is the same or different and is independently CH, CR or CA, or two adjacent Y groups together are a group of the formula (16), as described above. Preferably, V3 is C(R1)2 or N-A in formula (16), where R1 and A have a definition given above or one given with particular preference. More preferably, V3 is C(R1)2 in formula (16), where R1 has a definition given above or one given with particular preference. If V3 is C(R1)2, R1 is preferably the same and is an alkyl group having 1 to 10 carbon atoms or phenyl. If V3 is C(R1)2, R1 is more preferably the same and is a methyl group. If V3 is N-A, A is preferably an aromatic ring system which has 6 to 18 ring atoms and may be substituted by one or more R radicals. If V3 is N-A, A is more preferably phenyl which may be substituted by one or more R radicals. In formula (16), R # is preferably D or phenyl. If R # in the formula (1B) is D, n is preferably 1, 2, 3 or 4, more preferably 4. If R # in the formula (1B) is phenyl, n is preferably 1. In formula (16), n is most preferably 0.


In compounds of the formulae (1), (1a), (1b), (1c), (1d) and (1e), Y is the same or different at each instance and is preferably CH, CR or CA.


In compounds of the formulae (1), (1a), (1b), (1c), (1d) and (1e), Y is the same or different at each instance and is more preferably CH or CA.


If Y in compounds of the formulae (1), (1a), (1b), (1c), (1d) and (1e) is CA, A is preferably an aromatic or heteroaromatic ring system which has 6 to 24 ring atoms and may be substituted by one or more R radicals. If Y in compounds of the formulae (1), (1a), (1b), (1c), (1d) and (1e) is CA, A is more preferably carbazolyl, phenyl, 1,2-biphenyl, 1,4-biphenyl, triphenylenyl, phenylene-triphenylene, dibenzofuranyl or dibenzothiophenyl, which may be substituted by one or more R radicals. Preferably, in compounds of the formulae (1), (1a), (1b), (1c), (1d) and (1e), one Y is CA and the remaining Y are CH or CR, preferably CH. Preferably, Yin compounds of the formulae (1), (1a), (1b), (1c), (1d) and (1e) is the same and is CH or CR, preferably CH.


In compounds of the formulae (1), (1a) and (1e), R1 is the same or different at each instance and is independently an alkyl group having 1 to 20 carbon atoms, phenyl which may be substituted by one or more R radicals, or the two R1 groups together with the carbon atom to which they bind form a spiro compound. In compounds of the formulae (1), (1a) and (1e), R1 is preferably the same and is an alkyl group having 1 to 10 carbon atoms, or the two R1 groups together with the carbon atom to which they bind form a spiro compound. R1 is more preferably the same and is a methyl group, or the two R1 groups together with the carbon atom to which they bind form a spiro compound. R1 is most preferably methyl.


A particularly preferred embodiment of the compounds of the formula (1) or (1a) is compounds of the formulae (1b) and (1c), as described above, where the symbols Y, V, R #, m, Rx, Ry, L and ring A1 used have a definition given above or one specified as preferred hereinafter.


The invention therefore further provides an organic electroluminescent device as described above, wherein, in host material 1, V1 is 0 or NA and A has a definition given above or one specified as preferred hereinafter.


In compounds of the formulae (1), (1a), (1b), (1c), (1d) and (1e) as described above or described as preferred, Lisa bond or is a phenylene group of the formulae L-1, L-2 or L-3,




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where the phenylene groups L-1, L-2 and L-3 may be substituted by one or more R radicals. The phenylene groups L-1, L-2 and L-3 are preferably unsubstituted. A preferred phenylene group is L-2. In compounds of the formulae (1), (1a), (1b), (1c), (1d) and (1e) as described above or described as preferred, L is preferably a bond.


The substituent R # in compounds of the formulae (1), (1a), (1b), (1c), (1d) and (1e), or compounds of the formulae (1), (1a), (1b), (1c), (1d) and (1e) that are described as preferred, at each instance is independently D or an aryl group which has 6 to 12 carbon atoms and may be substituted by one or more R radicals.


If R # is Din compounds of the formulae (1), (1a), (1b), (1c), (1d) and (1e), it is preferable that m at each instance is 3.


If R # is an aryl group which has 6 to 12 carbon atoms and may be substituted by one or more R radicals in compounds of the formulae (1), (1a), (1b), (1c), (1d) and (1e), mat each instance is independently preferably 0, 1 or 2, more preferably 0 or 1. The aryl group which has 6 to 12 carbon atoms and may be substituted by one or more R radicals is preferably phenyl which may be substituted by one or more R radicals, where R has a definition given above or given with preference. R # is preferably unsubstituted phenyl or fully or partly deuterated phenyl. R # is more preferably unsubstituted phenyl. In compounds of the formulae (1), (1a), (1b), (1c), (1d) and (1e), one m is preferably 1, where R # denotes an aryl group which has 6 to 12 carbon atoms and may be substituted by one or more R radicals, and all other indices m are 0. In compounds of the formulae (1), (1a), (1b), (1c), (1d) and (1e), m at each instance is preferably 0.


The substituent R in compounds of the formulae (1), (1a), (1b), (1c), (1d), (1e) or the group (1B), or compounds of the formulae (1), (1a), (1b), (1c), (1d), (1e) described as preferred or a preferred group (1B), at each instance is selected independently 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 nonadjacent CH2 groups may be replaced by R2C═CR2, O or S and where one or more hydrogen atoms may be replaced by D, F, or CN. The substituent R at each instance is preferably selected independently from D, F, CN, a straight-chain alkyl group having 1 to 10 carbon atoms or a branched or cyclic alkyl group having 3 to 10 carbon atoms, wherein one or more hydrogen atoms of the alkyl group may be replaced by D, F, or CN.


The substituent R2 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 one or more nonadjacent CH2 groups may be replaced by O or S and where one or more hydrogen atoms may be replaced by D, F, or CN, and is preferably H or D.


The ring A1 in the diaza substituent of the formula (1C) of the host material 1 of the formulae (1), (1a), (1b), (1c), (1d) and (1e), as described above or described as preferred,




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conforms to the formula (1A),




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where V2 is O or S and the dotted line in formula (1C) denotes the attachment to the remainder of the formula (1) or the remainder of the formula (1a) of the host material 1.


Preferred embodiments of the diaza substituent of the formula (1C) of the host material 1 of the formulae (1), (1a), (1b), (1c), (1d) and (1e), as described above or described as preferred, conform to the formulae (1C-1), (1C-2), (1C-3) and (1C-4)




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where the dotted line, Rx, Ry, R # and m have a definition given above or given hereinafter.


The attachment of the substituent Rx to the diaza substituent of the formulae (1C), (1C-1), (1C-2), (1C-3) or (1C-4) in the host material 1 of the formulae (1), (1a), (1b), (1c), (1d) and (1e), as described above or described as preferred, is not limited, but is possible at either position.


Preferred embodiments of the diaza substituent of the formula (1C-1) conform to the formulae (1C-5) and (1C-6)




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where the dotted line, Rx, Ry, R # and m have a definition given above or given hereinafter.


Preferred embodiments of the diaza substituent of the formula (1C-2) conform to the formulae (1C-7) and (1C-8)




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where the dotted line, Rx, Ry, R # and m have a definition given above or given hereinafter.


Preferred embodiments of the diaza substituent of the formula (1C-3) conform to the formulae (1C-9) and (1C-10)




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where the dotted line, Rx, Ry, R # and m have a definition given above or given hereinafter.


Preferred embodiments of the diaza substituent of the formula (1C-4) conform to the formulae (1C-11) and (1C-12)




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where the dotted line, Rx, Ry, R # and m have a definition given above or given hereinafter.


The invention further provides the organic electroluminescent device as described above, wherein the host material 1 conforms to one of the formulae (1), (1a), (1b), (1c), (1d) and (1e), as described above or described as preferred, and the diaza substituent of the formula (1C) is selected from one of the formulae (1C-1), (1C-2), (1C-3), (1C-4), (1C-5), (1C-6), (1C-7), (1C-8), (1C-9), (1C-10), (1C-11) and (1C-12).


In a preferred embodiment of the host material 1 of the formulae (1), (1a), (1b), (1c), (1d) and (1e), as described above or described as preferred, the diaza substituent of the formula (1C) is selected from one of the formulae (1C-5), (1C-7), (1C-9) and (1C-11).


In a preferred embodiment of the host material 1 of the formulae (1), (1a), (1b), (1c), (1d) and (1e), as described above or described as preferred, the diaza substituent of the formula (1C) is selected from one of the formulae (1C-5), (1C-6), (1C-9) and (1C-10); more preferably from the formula (1C-5) or (1C-9).


In a preferred embodiment of the host material 1 of the formulae (1), (1a), (1b), (1c), (1d) and (1e), as described above or described as preferred, the diaza substituent of the formula (1C) is selected from one of the formulae (1C-7), (1C-8), (1C-11) and (1C-12); more preferably from the formula (1C-7) or (1C-11).


The attachment of the substituent Ry to the diaza substituent of the formulae (1C), (1C-1), (1C-2), (1C-3) or (1C-4) in the host material 1 of the formulae (1), (1a), (1b), (1c), (1d) and (1e), as described above or described as preferred, is not limited, but is possible at any of the four positions.


Preferably, Ry is at these two positions, as depicted in the formulae (1C-13) and (1C-14)




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where the dotted line, ring A1, Rx, Ry, R # and m have a definition given above or given hereinafter.


Particularly preferred embodiments of the diaza substituent of the formula (1C) of the host material 1 of the formulae (1), (1a), (1b), (1c), (1d) and (1e), as described above or described as preferred, conform to the formulae (1C-15) to (1C-30)




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where the dotted line, Rx, Ry, R # and m have a definition given above or given hereinafter.


Particularly preferred embodiments of the diaza substituent of the formula (1C) of the host material 1 of the formulae (1), (1a), (1b), (1c), (1d) and (1e), as described above or described as preferred, conform to the formulae (1C-15), (1C-17), (1C-19), (1C-21), (1C-23), (1C-25), (1C-27) and (1C-29), as described above.


Very particularly preferred embodiments of the diaza substituent of the formula (1C) of the host material 1 of the formulae (1), (1a), (1b), (1c), (1d) and (1e), as described above or described as preferred, conform to the formulae (1C-15), (1C-16), (1C-19), (1C-20), (1C-23), (1C-24), (1C-27) and (1C-28), as described above. Very particularly preferred embodiments of the diaza substituent of the formula (1C) of the host material 1 of the formulae (1), (1a), (1b), (1c), (1d) and (1e), as described above or described as preferred, conform to the formulae (1C-15), (1C-16), (1C-23) and (1C-24), as described above. Very particularly preferred embodiments of the diaza substituent of the formula (1C) of the host material 1 of the formulae (1), (1a), (1b), (1c), (1d) and (1e), as described above or described as preferred, conform to the formulae (1C-19), (1C-20), (1C-27) and (1C-28), as described above.


In the host material of the formulae (1), (1a), (1b), (1c), (1d) or (1e) having a diaza substituent of the formulae (1C), (1C-1), (1C-2), (1C-3), (1C-4), (1C-5), (1C-6), (1C-7), (1C-8), (1C-9), (1C-10), (1C-11), (1C-12), (1C-13), (1C-14), (1C-15), (1C-16), (1C-17), (1C-18), (1C-19), (1C-20), (1C-21), (1C-22), (1C-23), (1C-24), (1C-25), (1C-26), (1C-27), (1C-28), (1C-29) or (1C-30), as described above or described as preferred, the substituent Rx is L1-R* and the substituent Ry is L2-R*, where R* at each instance is independently an aromatic or heteroaromatic ring system which has 6 to 14 ring atoms and may be substituted by one or more R radicals, where R has a definition given above and L1 and L2 have a definition given above and specified hereinafter.


In compounds of the formulae (1), (1a), (1b), (1c), (1d) or (1e) having a diaza substituent of the formulae (1C), (1C-1), (1C-2), (1C-3), (1C-4), (1C-5), (1C-6), (1C-7), (1C-8), (1C-9), (1C-10), (1C-11), (1C-12), (1C-13), (1C-14), (1C-15), (1C-16), (1C-17), (1C-18), (1C-19), (1C-20), (1C-21), (1C-22), (1C-23), (1C-24), (1C-25), (1C-26), (1C-27), (1C-28), (1C-29) or (1C-30), as described above or described as preferred, L1 is a bond or is a phenylene group of the formula L-1, L-2 or L-3, where the phenylene groups L-1, L-2 and L-3 may be substituted by one or more R radicals. The phenylene groups L-1, L-2 and L-3 are preferably unsubstituted. Preferred phenyl groups for L1 are the groups L-2 and L-3. In compounds of the formulae (1), (1a), (1b), (1c), (1d) and (1e) as described above or described as preferred, L1 is preferably a bond.


In compounds of the formulae (1), (1a), (1b), (1c), (1d) or (1e) having a diaza substituent of the formulae (1C), (1C-1), (1C-2), (1C-3), (1C-4), (1C-5), (1C-6), (1C-7), (1C-8), (1C-9), (1C-10), (1C-11), (1C-12), (1C-13), (1C-14), (1C-15), (1C-16), (1C-17), (1C-18), (1C-19), (1C-20), (1C-21), (1C-22), (1C-23), (1C-24), (1C-25), (1C-26), (1C-27), (1C-28), (1C-29) or (1C-30), as described above or described as preferred, L2 is a bond or is a phenylene group of the formulae L-1, L-2 or L-3, where the phenylene groups L-1, L-2 and L-3 may be substituted by one or more R radicals. The phenylene groups L-1, L-2 and L-3 are preferably unsubstituted. Preferred phenyl groups for L1 are the groups L-2 and L-3. In compounds of the formulae (1), (1a), (1b), (1c), (1d) and (1e) as described above or described as preferred, L2 is preferably a bond.


In compounds of the formulae (1), (1a), (1b), (1c), (1d) or (1e) having a diaza substituent of the formulae (1C), (1C-1), (1C-2), (1C-3), (1C-4), (1C-5), (1C-6), (1C-7), (1C-8), (1C-9), (1C-10), (1C-11), (1C-12), (1C-13), (1C-14), (1C-15), (1C-16), (1C-17), (1C-18), (1C-19), (1C-20), (1C-21), (1C-22), (1C-23), (1C-24), (1C-25), (1C-26), (1C-27), (1C-28), (1C-29) or (1C-30), as described above or described as preferred, R* independently at each instance is preferably phenyl, 1,2-biphenyl, 1,3-biphenyl, 1,4-biphenyl, fluorenyl, dibenzofuranyl or dibenzothiophenyl, which may be substituted by one or more R radicals. Preferably, R* is unsubstituted.


In compounds of the formulae (1), (1a), (1b), (1c), (1d) or (1e) having a diaza substituent of the formulae (1C), (1C-1), (1C-2), (1C-3), (1C-4), (1C-5), (1C-6), (1C-7), (1C-8), (1C-9), (1C-10), (1C-11), (1C-12), (1C-13), (1C-14), (1C-15), (1C-16), (1C-17), (1C-18), (1C-19), (1C-20), (1C-21), (1C-22), (1C-23), (1C-24), (1C-25), (1C-26), (1C-27), (1C-28), (1C-29) or (1C-30), as described above or described as preferred, R* in Ry is more preferably phenyl, fluorenyl, dibenzofuranyl or dibenzothiophenyl, which may be substituted by one or more R radicals. Preferably, R* in Ry is unsubstituted.


In compounds of the formulae (1), (1a), (1b), (1c), (1d) or (1e) having a diaza substituent of the formulae (1C), (1C-1), (1C-2), (1C-3), (1C-4), (1C-5), (1C-6), (1C-7), (1C-8), (1C-9), (1C-10), (1C-11), (1C-12), (1C-13), (1C-14), (1C-15), (1C-16), (1C-17), (1C-18), (1C-19), (1C-20), (1C-21), (1C-22), (1C-23), (1C-24), (1C-25), (1C-26), (1C-27), (1C-28), (1C-29) or (1C-30), as described above or described as preferred, R* in Ry is more preferably phenyl, 1,4-biphenyl, fluorenyl, dibenzofuranyl or dibenzothiophenyl, which may be substituted by one or more R radicals. Preferably, R* in Rx is unsubstituted.


In compounds of the formulae (1), (1a), (1b), (1c), (1d) or (1e) having a diaza substituent of the formulae (1C), (1C-1), (1C-2), (1C-3), (1C-4), (1C-5), (1C-6), (1C-7), (1C-8), (1C-9), (1C-10), (1C-11), (1C-12), (1C-13), (1C-14), (1C-15), (1C-16), (1C-17), (1C-18), (1C-19), (1C-20), (1C-21), (1C-22), (1C-23), (1C-24), (1C-25), (1C-26), (1C-27), (1C-28), (1C-29) or (1C-30), as described above or described as preferred, V is preferably O.


Accordingly, the invention further provides the organic electroluminescent device as described above, wherein, in the host material of the formulae (1), (1a), (1b), (1c), (1d) or (1e) with a diaza substituent of the formulae (1C), (1C-1), (1C-2), (1C-3), (1C-4), (1C-5), (1C-6), (1C-7), (1C-8), (1C-9), (1C-10), (1C-11), (1C-12), (1C-13), (1C-14), (1C-15), (1C-16), (1C-17), (1C-18), (1C-19), (1C-20), (1C-21), (1C-22), (1C-23), (1C-24), (1C-25), (1C-26), (1C-27), (1C-28), (1C-29) or (1C-30), as described above or described as preferred, V is O.


Examples of suitable host materials of the formulae (1) as described above or described as preferred that are selected in accordance with the invention, and are preferably used in combination with at least one compound of the formula (2) in the electroluminescent device of the invention, are the structures given below in table 1.









TABLE 1









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Further examples of compounds of the formula (1) are described in the implementation section.


Particularly suitable compounds of the formula (1) that are preferably used in combination with at least one compound of the formula (2) in the electroluminescent device of the invention are the compounds E1 to E27:




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The preparation of the compounds of the formula (1) or of the preferred compounds from table 1 and of the compounds E1 to E27 is known to those skilled in the art. The compounds may be prepared by synthesis steps known to the person skilled in the art, for example halogenation, preferably bromination, and a subsequent organometallic coupling reaction, for example Suzuki coupling, Heck coupling or Hartwig-Buchwald coupling.


Precursor compounds for compounds of the formula (1) can be prepared according to scheme 1 below, where the symbols and indices have one of the definitions given above and L denotes a bond, and m and R # have one of the definitions specified above or specified as preferred.




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The adjustment of the preparation of the host material 1 containing a linker L is sufficiently well known to the person skilled in the art and is described in the implementation section. The conditions of the preparation as described in the implementation section are also applicable to the synthesis of the host material 1 according to scheme 1.


There follows a description of the host material 2 and its preferred embodiments that is/are present in the device of the invention. The preferred embodiments of the host material 1 of the formula (1) are also applicable to the mixture and/or formulation of the invention.


Host material 2 is at least one compound of the formula (2),




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    • where the symbols and indices used are as follows:

    • K, M are each independently an unsubstituted or partly or fully deuterated or R*-monosubstituted aromatic ring system having 6 to 40 ring atoms when x and y are 0 and when x1 and y1 are 0, or

    • K, M each independently together with X or X1 form a heteroaromatic ring system having 14 to 40 ring atoms when the value of x, x1, y and/or y1 is 1;

    • x, x1 at each instance are each independently 0 or 1;

    • y, y1 at each instance are each independently 0 or 1;

    • X and X1 at each instance are each independently a bond or C(R+)2;

    • R0 at each instance is independently an unsubstituted or partly or fully deuterated aromatic ring system having 6 to 18 carbon atoms;

    • R+ at each instance is independently a straight-chain or branched alkyl group having 1 to 4 carbon atoms and

    • c, d, e and f are independently 0 or 1.





In one embodiment of the invention, for the device of the invention, compounds of the formula (2) as described above are selected, and these are used in the light-emitting layer with compounds of the formula (1) as described above or described as preferred or with the compounds from table 1 or the compounds E1 to E27.


In a preferred embodiment of the device of the invention, compounds of the formula (2) in which x, y, x1 and y1 are 0 are used as host material 2. Compounds of the formula (2) in which x, x1, y and y1 at each instance are 0 may be represented by the following formula (2a):




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    • where R0, c, d, e and f are as defined above or hereinafter and

    • K and M are each independently an unsubstituted or partly or fully deuterated or R*-monosubstituted aromatic ring system having 6 to 40 ring atoms.





In preferred compounds of the formula (2a), the sum total of the indices c+d+e+f is preferably 0 or 1 and R0 is as defined as preferred above or hereinafter.


In compounds of the formula (2) or (2a), R0 at each instance is preferably independently an unsubstituted aromatic ring system having 6 to 18 carbon atoms. R0 at each instance is preferably independently phenyl, 1,3-biphenyl, 1,4-biphenyl, naphthyl or triphenylenyl. R0 at each instance is more preferably independently phenyl.


In compounds of the formula (2) or (2a) the indices c, d, e and f are more preferably 0.


In compounds of the formula (2) or (2a), K and M at each instance are preferably independently an unsubstituted or partly deuterated aromatic ring system having 6 to 40 ring atoms as described above. K and M in compounds of the formula (2) or (2a) at each instance are more preferably independently phenyl, deuterated phenyl, 1,3-biphenyl, 1,4-biphenyl, terphenyl, partly deuterated terphenyl, quaterphenyl, naphthyl, fluorenyl, 9,9-diphenylfluorenyl, bispirofluorenyl or triphenylenyl.


The invention accordingly further provides an organic electroluminescent device as described above or described as preferred, wherein the at least one compound of the formula (2) corresponds to a compound of the formula (2a) or to a preferred embodiment of the compound of the formula (2a).


In a preferred embodiment of the device of the invention, compounds of the formula (2) in which x1 and y1 are 0, x and y are 0 or 1 and the sum of x and y is 1 or 2 are used as host material 2. Compounds of the formula (2) in which x1 and y1 are 0, x and y are 0 or 1 and the sum of x and y is 1 or 2 may be represented by the following formula (2b),




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    • where X, x, y, R0, c, d, e and f are as defined above or hereinafter,

    • M is an unsubstituted or partly or fully deuterated or R*-monosubstituted aromatic ring system having 6 to 40 ring atoms and

    • K together with X forms a heteroaromatic ring system having 14 to 40 ring atoms when the value of x or y is 1 or both values x and y are 1.





In preferred compounds of the formula (2b), the sum total of the indices c+d+e+f is preferably 0, 1 or 2 and R0 is as defined as described above or described as preferred.


In compounds of the formula (2) or (2b), the indices c, d, e and f are more preferably 0 or 1. In compounds of the formula (2) or (2b), the indices c, d, e and f are even more preferably 0. In compounds of the formula (2) or (2b), the indices c, d, e and f are even more preferably 1. In compounds of the formula (2) or (2b), the indices c, d, e and f are even more preferably 2.


In compounds of the formula (2) or (2b), K preferably forms a heteroaromatic ring system when the sum of x+y is 1 or 2. In compounds of the formula (2) or (2b), X is preferably a direct bond or C(CH3)2.


Preferred compounds of the formula (2) or (2b) may be represented by the formulae (2b-1) to (2b-6),




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where M, R0, c, d, e and f are defined as described above or described as preferred.


In compounds of the formulae (2), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5) or (2b-6), M is preferably an unsubstituted or partly deuterated aromatic ring system having 6 to 40 ring atoms as described above. M in compounds of the formulae (2), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5) or (2b-6) is more preferably phenyl, deuterated phenyl, 1,3-biphenyl, 1,4-biphenyl, terphenyl, partially deuterated terphenyl, quaterphenyl, naphthyl, fluorenyl, 9,9-diphenylfluorenyl, bispirofluorenyl or triphenylenyl.


In compounds of the formulae (2b-1), (2b-2), (2b-3), (2b-4), (2b-5) or (2b-6), c, d, e and f are preferably 0 or 1.


The invention accordingly further provides an organic electroluminescent device as described above or described as preferred, wherein the at least one compound of the formula (2) corresponds to a compound of the formula (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5) or (2b-6) or to a preferred embodiment of these compounds.


In a preferred embodiment of the device of the invention, compounds of the formula (2) in which c and f are 0 or 1, d and e are 0 and x, x1, y and y1 independently at each instance represent 0 or 1, but the sum of x and y is at least 1 and the sum of x1 and y1 is at least 1, are used as host material 2. Such compounds of the formula (2) as described above may preferably be represented by the following formula (2c),




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    • where X and X1 are as defined above or hereinafter,

    • K and M each independently together with X or X 1 form a heteroaromatic ring system having 14 to 40 ring atoms,

    • x, x1, y and/or y1 are 0 or 1 and the sum of x and y is at least 1 and the sum of x1 and y1 is at least 1.





In preferred compounds of the formula (2c) the sum of x and y is 1 or 2 and the sum of x1 and y1 is 1. In particularly preferred compounds of the formula (2c) the sum of x and y is 1 and the sum of x1 and y1 is in each case 1.


In compounds of the formula (2) or (2c) K and M thus preferably form a heteroaromatic ring system. In compounds of the formula (2) or (2c) X and X1 are preferably a direct bond or C(CH3)2.


Preferred compounds of the formula (2) or (2c) may be represented by the formulae (2c-1) to (2c-8),




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Preferred compounds of the formula (2c) are also the compounds H9, H11, H12, H13, H14, H15, H19 and H20 as described hereinafter.


The invention accordingly further provides an organic electroluminescent device as described above or described as preferred, wherein the at least one compound of the formula (2) corresponds to a compound of the formulae (2c), (2c-1), (2c-2), (2c-3), (2c-4), (2c-5), (2c-6), (2c-7) or (2c-8).


In a preferred embodiment of the compounds of the formulae (2), (2a), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5) or (2b-6), the carbazole and the bridged carbazole are joined to one another, each in the 3 position.


In a preferred embodiment of the compounds of the formula (2c), the two bridged carbazoles are joined to one another, each in the 3 position.


Examples of suitable host materials of the formulae (2), (2a), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5) and (2c) that are selected in accordance with the invention and are preferably used in combination with at least one compound of the formula (1) in the electroluminescent device of the invention are the structures given below in table 2.









TABLE 2









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Particularly suitable compounds of the formula (2) that are preferably used in combination with at least one compound of the formula (1) in the electroluminescent device of the invention are the compounds H1 to H27:




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The preparation of the compounds of the formula (2) or of the preferred compounds of the formulae (2), (2a), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5) and (2c) and of the compounds from table 2 and H1 to H27 is known to the person skilled in the art. The compounds may be prepared by synthesis steps known to the person skilled in the art, for example halogenation, preferably bromination, and a subsequent organometallic coupling reaction, for example Suzuki coupling, Heck coupling or Hartwig-Buchwald coupling. Some of the compounds of the formula (2) are commercially available.


The aforementioned host materials of the formula (1) and the embodiments thereof that are described as preferred or the compounds from table 1 and the compounds E1 to E27 can be combined as desired in the device of the invention with the host materials of the formulae (2), (2a), (2b), (2), (2a), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5), (2c), (2c-1), (2c-2), (2c-3), (2c-4), (2c-5), (2c-6), (2c-7) and (2c-8) mentioned and the embodiments thereof that are described as preferred or the compounds from table 2 or the compounds H1 to H27.


Aforementioned specific combinations of host materials of the formula (1) with host materials of the formula (2) are preferred as described above. Preferred combinations of host materials are likewise described hereinafter.


The invention likewise further provides mixtures comprising at least one compound of the formula (1) and at least one compound of the formula (2)




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    • where the symbols and indices used are as follows:

    • ring A1 in formula (1) conforms to the formula (1A)







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    • V is O or S;

    • V1 is O, S, C(R1)2 or N-A;

    • V2 is O or S;

    • Y is the same or different at each instance and is independently CH, CR or CA, or two adjacent Y groups together form a group of the formula (1B)







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    • and the remaining Y groups are independently CH or CR, where V3 is O, S, C(R1)2 or N-A and the dotted bonds show the linkage of this group to the remainder of the formula (1);

    • Rx is L1-R*;

    • Ry is L2-R*;

    • R* independently at each instance is an aromatic or heteroaromatic ring system which has 6 to 14 ring atoms and may be substituted by one or more R radicals;

    • L, L1, L2 are each independently a bond or a phenylene group which may be substituted by one or more R radicals;

    • A is the same or different at each instance and is an aromatic or heteroaromatic ring system which has 6 to 30 ring atoms and may be substituted by one or more R radicals;

    • n is 0, 1, 2, 3 or 4;

    • m is 0, 1, 2 or 3;

    • R # is D or an aryl group which has 6 to 12 carbon atoms and may be substituted by one or more R radicals;

    • R1 is the same or different at each instance and is an alkyl group having 1 to 20 carbon atoms, phenyl which may be substituted by one or more R radicals, or the two R1 radicals together with the carbon atom to which they bind form a spiro compound;

    • R is the same or different at each instance and is 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 nonadjacent CH 2 groups may be replaced by R2C═CR2, O or S and where one or more hydrogen atoms may be replaced by D, F, or CN;

    • R2 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 one or more nonadjacent CH2 groups may be replaced by O or S and where one or more hydrogen atoms may be replaced by D, F, or CN;

    • K, M are each independently an unsubstituted or partly or fully deuterated or R*-monosubstituted aromatic ring system having 6 to 40 ring atoms when x and y are 0 and when x1 and y1 are 0, or

    • K, M each independently together with X or X′ form a heteroaromatic ring system having 14 to 40 ring atoms when the value of x, x1, y and/or y1 is 1;

    • x, x1 at each instance are each independently 0 or 1;

    • y, y1 at each instance are each independently 0 or 1;

    • X and X′ at each instance are each independently a bond or C(R+)2;

    • R0 at each instance is independently an unsubstituted or partly or fully deuterated aromatic ring system having 6 to 18 carbon atoms;

    • R+ at each instance is independently a straight-chain or branched alkyl group having 1 to 4 carbon atoms and

    • c, d, e and f are independently 0 or 1.





The remarks concerning the host materials of the formulae (1) and (2) and preferred embodiments thereof and the combination thereof are correspondingly also applicable to the mixture of the invention.


Particularly preferred mixtures of the host materials of the formula (1) with the host materials of the formula (2) for the device of the invention are obtained by combination of the compounds E1 to E27 with the compounds from table 2.


Very particularly preferred mixtures of the host materials of the formula (1) with the host materials of the formula (2) for the device of the invention are obtained by combination of the compounds E1 to E27 with the compounds H1 to H27 as shown hereinafter in table 3.

















TABLE 3







M1
E1
H1
M2
E2
H1
M3
E3
H1


M4
E4
H1
M5
E5
H1
M6
E6
H1


M7
E7
H1
M8
E8
H1
M9
E9
H1


M10
E10
H1
M11
E11
H1
M12
E12
H1


M13
E13
H1
M14
E14
H1
M15
E15
H1


M16
E16
H1
M17
E17
H1
M18
E18
H1


M19
E19
H1
M20
E20
H1
M21
E21
H1


M22
E22
H1
M23
E23
H1
M24
E24
H1


M25
E25
H1
M26
E26
H1
M27
E27
H1


M28
E1
H2
M29
E2
H2
M30
E3
H2


M31
E4
H2
M32
E5
H2
M33
E6
H2


M34
E7
H2
M35
E8
H2
M36
E9
H2


M37
E10
H2
M38
E11
H2
M39
E12
H2


M40
E13
H2
M41
E14
H2
M42
E15
H2


M43
E16
H2
M44
E17
H2
M45
E18
H2


M46
E19
H2
M47
E20
H2
M48
E21
H2


M49
E22
H2
M50
E23
H2
M51
E24
H2


M52
E25
H2
M53
E26
H2
M54
E27
H2


M55
E1
H3
M56
E2
H3
M57
E3
H3


M58
E4
H3
M59
E5
H3
M60
E6
H3


M61
E7
H3
M62
E8
H3
M63
E9
H3


M64
E10
H3
M65
E11
H3
M66
E12
H3


M67
E13
H3
M68
E14
H3
M69
E15
H3


M70
E16
H3
M71
E17
H3
M72
E18
H3


M73
E19
H3
M74
E20
H3
M75
E21
H3


M76
E22
H3
M77
E23
H3
M78
E24
H3


M79
E25
H3
M80
E26
H3
M81
E27
H3


M82
E1
H4
M83
E2
H4
M84
E3
H4


M85
E4
H4
M86
E5
H4
M87
E6
H4


M88
E7
H4
M89
E8
H4
M90
E9
H4


M91
E10
H4
M92
E11
H4
M93
E12
H4


M94
E13
H4
M95
E14
H4
M96
E15
H4


M97
E16
H4
M98
E17
H4
M99
E18
H4


M100
E19
H4
M101
E20
H4
M102
E21
H4


M103
E22
H4
M104
E23
H4
M105
E24
H4


M106
E25
H4
M107
E26
H4
M108
E27
H4


M109
E1
H5
M110
E2
H5
M111
E3
H5


M112
E4
H5
M113
E5
H5
M114
E6
H5


M115
E7
H5
M116
E8
H5
M117
E9
H5


M118
E10
H5
M119
E11
H5
M120
E12
H5


M121
E13
H5
M122
E14
H5
M123
E15
H5


M124
E16
H5
M125
E17
H5
M126
E18
H5


M127
E19
H5
M128
E20
H5
M129
E21
H5


M130
E22
H5
M131
E23
H5
M132
E24
H5


M133
E25
H5
M134
E26
H5
M135
E27
H5


M136
E1
H6
M137
E2
H6
M138
E3
H6


M139
E4
H6
M140
E5
H6
M141
E6
H6


M142
E7
H6
M143
E8
H6
M144
E9
H6


M145
E10
H6
M146
E11
H6
M147
E12
H6


M148
E13
H6
M149
E14
H6
M150
E15
H6


M151
E16
H6
M152
E17
H6
M153
E18
H6


M154
E19
H6
M155
E20
H6
M156
E21
H6


M157
E22
H6
M158
E23
H6
M159
E24
H6


M160
E25
H6
M161
E26
H6
M162
E27
H6


M163
E1
H7
M164
E2
H7
M165
E3
H7


M166
E4
H7
M167
E5
H7
M168
E6
H7


M169
E7
H7
M170
E8
H7
M171
E9
H7


M172
E10
H7
M173
E11
H7
M174
E12
H7


M175
E13
H7
M176
E14
H7
M177
E15
H7


M178
E16
H7
M179
E17
H7
M180
E18
H7


M181
E19
H7
M182
E20
H7
M183
E21
H7


M184
E22
H7
M185
E23
H7
M186
E24
H7


M187
E25
H7
M188
E26
H7
M189
E27
H7


M190
E1
H8
M191
E2
H8
M192
E3
H8


M193
E4
H8
M194
E5
H8
M195
E6
H8


M196
E7
H8
M197
E8
H8
M198
E9
H8


M199
E10
H8
M200
E11
H8
M201
E12
H8


M202
E13
H8
M203
E14
H8
M204
E15
H8


M205
E16
H8
M206
E17
H8
M207
E18
H8


M208
E19
H8
M209
E20
H8
M210
E21
H8


M211
E22
H8
M212
E23
H8
M213
E24
H8


M214
E25
H8
M215
E26
H8
M216
E27
H8


M217
E1
H9
M218
E2
H9
M219
E3
H9


M220
E4
H9
M221
E5
H9
M222
E6
H9


M223
E7
H9
M224
E8
H9
M225
E9
H9


M226
E10
H9
M227
E1
H9
M228
E12
H9


M229
E13
H9
M230
E14
H9
M231
E15
H9


M232
E16
H9
M233
E17
H9
M234
E18
H9


M235
E19
H9
M236
E20
H9
M237
E21
H9


M238
E22
H9
M239
E23
H9
M240
E24
H9


M241
E25
H9
M242
E26
H9
M243
E27
H9


M244
E1
H10
M245
E2
H10
M246
E3
H10


M247
E4
H10
M248
E5
H10
M249
E6
H10


M250
E7
H10
M251
E8
H10
M252
E9
H10


M253
E10
H10
M254
E11
H10
M255
E12
H10


M256
E13
H10
M257
E14
H10
M258
E15
H10


M259
E16
H10
M260
E17
H10
M261
E18
H10


M262
E19
H10
M263
E20
H10
M264
E21
H10


M265
E22
H10
M266
E23
H10
M267
E24
H10


M268
E25
H10
M269
E26
H10
M270
E27
H10


M271
E1
H11
M272
E2
H11
M273
E3
H11


M274
E4
H11
M275
E5
H11
M276
E6
H11


M277
E7
H11
M278
E8
H11
M279
E9
H11


M280
E10
H11
M281
E11
H11
M282
E12
H11


M283
E13
H11
M284
E14
H11
M285
E15
H11


M286
E16
H11
M287
E17
H11
M288
E18
H11


M289
E19
H11
M290
E20
H11
M291
E21
H11


M292
E22
H11
M293
E23
H11
M294
E24
H11


M295
E25
H11
M296
E26
H11
M297
E27
H11


M298
E1
H12
M299
E2
H12
M300
E3
H12


M301
E4
H12
M302
E5
H12
M303
E6
H12


M304
E7
H12
M305
E8
H12
M306
E9
H12


M307
E10
H12
M308
E11
H12
M309
E12
H12


M310
E13
H12
M311
E14
H12
M312
E15
H12


M313
E16
H12
M314
E17
H12
M315
E18
H12


M316
E19
H12
M317
E20
H12
M318
E21
H12


M319
E22
H12
M320
E23
H12
M321
E24
H12


M322
E25
H12
M323
E26
H12
M324
E27
H12


M325
E1
H13
M326
E2
H13
M327
E3
H13


M328
E4
H13
M329
E5
H13
M330
E6
H13


M331
E7
H13
M332
E8
H13
M333
E9
H13


M334
E10
H13
M335
E11
H13
M336
E12
H13


M337
E13
H13
M338
E14
H13
M339
E15
H13


M340
E16
H13
M341
E17
H13
M342
E18
H13


M343
E19
H13
M344
E20
H13
M345
E21
H13


M346
E22
H13
M347
E23
H13
M348
E24
H13


M349
E25
H13
M350
E26
H13
M351
E27
H13


M352
E1
H14
M353
E2
H14
M354
E3
H14


M355
E4
H14
M356
E5
H14
M357
E6
H14


M358
E7
H14
M359
E8
H14
M360
E9
H14


M361
E10
H14
M362
E11
H14
M363
E12
H14


M364
E13
H14
M365
E14
H14
M366
E15
H14


M367
E16
H14
M368
E17
H14
M369
E18
H14


M370
E19
H14
M371
E20
H14
M372
E21
H14


M373
E22
H14
M374
E23
H14
M375
E24
H14


M376
E25
H14
M377
E26
H14
M378
E27
H14


M379
E1
H15
M380
E2
H15
M381
E3
H15


M382
E4
H15
M383
E5
H15
M384
E6
H15


M385
E7
H15
M386
E8
H15
M387
E9
H15


M388
E10
H15
M389
E11
H15
M390
E12
H15


M391
E13
H15
M392
E14
H15
M393
E15
H15


M394
E16
H15
M395
E17
H15
M396
E18
H15


M397
E19
H15
M398
E20
H15
M399
E21
H15


M400
E22
H15
M401
E23
H15
M402
E24
H15


M403
E25
H15
M404
E26
H15
M405
E27
H15


M406
E1
H16
M407
E2
H16
M408
E3
H16


M409
E4
H16
M410
E5
H16
M411
E6
H16


M412
E7
H16
M413
E8
H16
M414
E9
H16


M415
E10
H16
M416
E11
H16
M417
E12
H16


M418
E13
H16
M419
E14
H16
M420
E15
H16


M421
E16
H16
M422
E17
H16
M423
E18
H16


M424
E19
H16
M425
E20
H16
M426
E21
H16


M427
E22
H16
M428
E23
H16
M429
E24
H16


M430
E25
H16
M431
E26
H16
M432
E27
H16


M433
E1
H17
M434
E2
H17
M435
E3
H17


M436
E4
H17
M437
E5
H17
M438
E6
H17


M439
E7
H17
M440
E8
H17
M441
E9
H17


M442
E10
H17
M443
E11
H17
M444
E12
H17


M445
E13
H17
M446
E14
H17
M447
E15
H17


M448
E16
H17
M449
E17
H17
M450
E18
H17


M451
E19
H17
M452
E20
H17
M453
E21
H17


M454
E22
H17
M455
E23
H17
M456
E24
H17


M457
E25
H17
M458
E26
H17
M459
E27
H17


M460
E1
H18
M461
E2
H18
M462
E3
H18


M463
E4
H18
M464
E5
H18
M465
E6
H18


M466
E7
H18
M467
E8
H18
M468
E9
H18


M469
E10
H18
M470
E11
H18
M471
E12
H18


M472
E13
H18
M473
E14
H18
M474
E15
H18


M475
E16
H18
M476
E17
H18
M477
E18
H18


M478
E19
H18
M479
E20
H18
M480
E21
H18


M481
E22
H18
M482
E23
H18
M483
E24
H18


M484
E25
H18
M485
E26
H18
M486
E27
H18


M487
E1
H19
M488
E2
H19
M489
E3
H19


M490
E4
H19
M491
E5
H19
M492
E6
H19


M493
E7
H19
M494
E8
H19
M495
E9
H19


M496
E10
H19
M497
E11
H19
M498
E12
H19


M499
E13
H19
M500
E14
H19
M501
E15
H19


M502
E16
H19
M503
E17
H19
M504
E18
H19


M505
E19
H19
M506
E20
H19
M507
E21
H19


M508
E22
H19
M509
E23
H19
M510
E24
H19


M511
E25
H19
M512
E26
H19
M513
E27
H19


M514
E1
H20
M515
E2
H20
M516
E3
H20


M517
E4
H20
M518
E5
H20
M519
E6
H20


M520
E7
H20
M521
E8
H20
M522
E9
H20


M523
E10
H20
M524
E11
H20
M525
E12
H20


M526
E13
H20
M527
E14
H20
M528
E15
H20


M529
E16
H20
M530
E17
H20
M531
E18
H20


M532
E19
H20
M533
E20
H20
M534
E21
H20


M535
E22
H20
M536
E23
H20
M537
E24
H20


M538
E25
H20
M539
E26
H20
M540
E27
H20


M541
E1
H21
M542
E2
H21
M543
E3
H21


M544
E4
H21
M545
E5
H21
M546
E6
H21


M547
E7
H21
M548
E8
H21
M549
E9
H21


M550
E10
H21
M551
E11
H21
M552
E12
H21


M553
E13
H21
M554
E14
H21
M555
E15
H21


M556
E16
H21
M557
E17
H21
M558
E18
H21


M559
E19
H21
M560
E20
H21
M561
E21
H21


M562
E22
H21
M563
E23
H21
M564
E24
H21


M565
E25
H21
M566
E26
H21
M567
E27
H21


M568
E1
H22
M569
E2
H22
M570
E3
H22


M571
E4
H22
M572
E5
H22
M573
E6
H22


M574
E7
H22
M575
E8
H22
M576
E9
H22


M577
E10
H22
M578
E11
H22
M579
E12
H22


M580
E13
H22
M581
E14
H22
M582
E15
H22


M583
E16
H22
M584
E17
H22
M585
E18
H22


M586
E19
H22
M587
E20
H22
M588
E21
H22


M589
E22
H22
M590
E23
H22
M591
E24
H22


M592
E25
H22
M593
E26
H22
M594
E27
H22


M595
E1
H23
M596
E2
H23
M597
E3
H23


M598
E4
H23
M599
E5
H23
M600
E6
H23


M601
E7
H23
M602
E8
H23
M603
E9
H23


M604
E10
H23
M605
E11
H23
M606
E12
H23


M607
E13
H23
M608
E14
H23
M609
E15
H23


M610
E16
H23
M611
E17
H23
M612
E18
H23


M613
E19
H23
M614
E20
H23
M615
E21
H23


M616
E22
H23
M617
E23
H23
M618
E24
H23


M619
E25
H23
M620
E26
H23
M621
E27
H23


M622
E1
H24
M623
E2
H24
M624
E3
H24


M625
E4
H24
M626
E5
H24
M627
E6
H24


M628
E7
H24
M629
E8
H24
M630
E9
H24


M631
E10
H24
M632
E11
H24
M633
E12
H24


M634
E13
H24
M635
E14
H24
M636
E15
H24


M637
E16
H24
M638
E17
H24
M639
E18
H24


M640
E19
H24
M641
E20
H24
M642
E21
H24


M643
E22
H24
M644
E23
H24
M645
E24
H24


M646
E25
H24
M647
E26
H24
M648
E27
H24


M649
E1
H25
M650
E2
H25
M651
E3
H25


M652
E4
H25
M653
E5
H25
M654
E6
H25


M655
E7
H25
M656
E8
H25
M657
E9
H25


M658
E10
H25
M659
E11
H25
M660
E12
H25


M661
E13
H25
M662
E14
H25
M663
E15
H25


M664
E16
H25
M665
E17
H25
M666
E18
H25


M667
E19
H25
M668
E20
H25
M669
E21
H25


M670
E22
H25
M671
E23
H25
M672
E24
H25


M673
E25
H25
M674
E26
H25
M675
E27
H25


M676
E1
H26
M677
E2
H26
M678
E3
H26


M679
E4
H26
M680
E5
H26
M681
E6
H26


M682
E7
H26
M683
E8
H26
M684
E9
H26


M685
E10
H26
M686
E11
H26
M687
E12
H26


M688
E13
H26
M689
E14
H26
M690
E15
H26


M691
E16
H26
M692
E17
H26
M693
E18
H26


M694
E19
H26
M695
E20
H26
M696
E21
H26


M697
E22
H26
M698
E23
H26
M699
E24
H26


M700
E25
H26
M701
E26
H26
M702
E27
H26


M703
E1
H27
M704
E2
H27
M705
E3
H27


M706
E4
H27
M707
E5
H27
M708
E6
H27


M709
E7
H27
M710
E8
H27
M711
E9
H27


M712
E10
H27
M713
E11
H27
M714
E12
H27


M715
E13
H27
M716
E14
H27
M717
E15
H27


M718
E16
H27
M719
E17
H27
M720
E18
H27


M721
E19
H27
M722
E20
H27
M723
E21
H27


M724
E22
H27
M725
E23
H27
M726
E24
H27


M727
E25
H27
M728
E26
H27
M729
E27
H27









The concentration of the electron-transporting host material of the formula (1) 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 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 hole-transporting host material of the formula (2) 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 in the range from 10% by weight to 95% by weight, preferably in the range from 15% by weight to 90% by weight, more preferably in the range from 15% by weight to 80% by weight, even more preferably in the range from 20% by weight to 70% by weight, very especially preferably in the range from 40% by weight to 80% by weight and most preferably in the range from 50% by weight to 70% 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 1 and 2, as described above or described as preferred, especially mixtures M1 to M729, also contains at least one phosphorescent emitter.


The present invention also relates to an organic electroluminescent device as described above or described as preferred, wherein the light-emitting layer, as well as the aforementioned host materials 1 and 2, as described above or described as preferred, especially the material combinations M1 to M729, also comprises at least one phosphorescent emitter.


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 formula (3),




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    • where the symbols and indices for this formula (3) are defined as follows:

    • n+m is 3, n is 1 or 2, m is 2 or 1,

    • X is N or CR,

    • R is H, D, 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 7 carbon 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 (3) as described above.


In emitters of the formula (3), n is preferably 1 and m is preferably 2.


In emitters of the formula (3), preferably, one X is selected from N and the other X are CR.


In emitters of the formula (3) at least one R is preferably different from H. In emitters of the formula (3) preferably two R are different from H and have one of the other definitions given above for the emitters of the formula (3).


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




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

    • R1 is H or D, R2 is H, D, 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)




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

    • R1 is H or D, R2 is H, D, F 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 examples of phosphorescent emitters are listed in table 4 below.









TABLE 4









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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 M729 is preferably combined with a compound of the formula (3) or a compound of the formulae (I) to (VIII) or a compound from table 4.


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, said layer having the inventive combination of the host materials of the formulae (1) and (2) and the appropriate 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(T1 in eV)=1240/E(T1 in nm)=1240/PLmax. (in nm).


Preferred phosphorescent emitters are accordingly yellow emitters, preferably of the formula (3), of the formulae (I) to (VIII) or from table 4, the triplet energy T1 of which is preferably ˜2.3 eV to ˜2.1 eV.


Preferred phosphorescent emitters are accordingly green emitters, preferably of the formula (3), of the formulae (I) to (VIII) or from table 4, the triplet energy T1 of which is preferably ˜2.5 eV to ˜2.3 eV.


Particularly preferred phosphorescent emitters are accordingly green emitters, preferably of the formula (3), of the formulae (I) to (VIII) or from table 4 as described above, the triplet energy T1 of which is preferably ˜2.5 eV to ˜2.3 eV.


Most preferably, green emitters, preferably of the formula (3), of the formulae (I) to (VIII) or from table 4, as described above, are selected for the composition 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.


Preferred fluorescent emitters are selected from the class of the arylamines. An arylamine or an aromatic amine in the context of this invention is understood to mean a compound containing three substituted or unsubstituted aromatic or heteroaromatic ring systems bonded directly to the nitrogen.


In a further preferred embodiment of the invention, the at least one light-emitting layer of the organic electroluminescent device, as well as the host materials 1 and 2, as described above or described as preferred, may comprise further host materials or matrix materials, called mixed matrix systems. The mixed matrix systems preferably comprise three or four different matrix materials, more preferably three different matrix materials (in other words, one further matrix component in addition to the host materials 1 and 2, as described above). Particularly suitable matrix materials which can be used in combination as matrix component in a mixed matrix system are selected from wide-band gap materials, bipolar host materials, electron transport materials (ETM) and hole transport materials (HTM).


A wide-band gap material is understood herein to mean a material within the scope of the disclosure of U.S. Pat. No. 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.


One source of more detailed information about mixed matrix systems is the application WO 2010/108579. Particularly suitable matrix materials which can be used in combination with the host materials 1 and 2 as described above or described as preferred, as matrix components of a mixed matrix system in phosphorescent or fluorescent organic electroluminescent devices, are selected from the preferred matrix materials specified below for phosphorescent emitters or the preferred matrix materials for fluorescent emitters, according to what type of emitter is used. Preferably, the mixed matrix system is optimized for an emitter of the formula (3), the formulae (I) to (VIII), or from table 4.


In one embodiment of the present invention, the mixture does not comprise any further constituents, i.e. functional materials, aside from the constituents of electron-transporting host material of the formula (1) and hole-transporting host material of the formula (2). 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 vapour deposition of the host materials for the light-emitting layer and have a constant mixing ratio in the vapour deposition. In this way, it is possible in a simple and rapid manner to achieve the vapour 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 also comprises the phosphorescent emitter, as described above, in addition to the constituents of electron-transporting host material of the formula (1) and hole-transporting host material of the formula (2). In the case of a suitable mixing ratio in the vapour deposition, this mixture may also be used as the sole material source, as described above.


The components or constituents of the light-emitting layer of the device of the invention may thus be processed by vapour 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. 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.


The present invention therefore further provides a formulation comprising an inventive mixture of host materials 1 and 2, as described above, optionally in combination with a phosphorescent emitter, as described above or described as preferred, and at least one solvent.


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, methyl benzoate, 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, hexamethylindane or mixtures of these solvents.


The formulation here may also comprise at least one further organic or inorganic compound which is likewise used in the light-emitting layer of the device of the invention, especially a further emitting compound and/or a further matrix material. Suitable emitting compounds and further matrix materials have already been detailed 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 the formula (2) 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 light-emitting layer in the device of the invention, according to the preferred embodiments and the emitting compound, preferably contains the matrix material of the formula (1) and the matrix material of the formula (2) in a percentage by volume ratio between 3:1 and 1:3, preferably between 1:2.5 and 1:1, more preferably between 1:2 and 1:1. If the compounds are processed from solution, preference is given to using the corresponding ratio in % by weight rather than the above-specified ratio 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 is a monoamine that does not contain a carbazole unit. The hole-injecting material and hole-transporting material preferably comprises a monoamine containing a fluorenyl or bispirofluorenyl group, but no carbazole unit.


Preferred monoamines which are used in accordance with the invention in the organic layer of the device of the invention may be described by the formula (4)




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    • where the symbols and indices for this formula (4) are defined as follows:

    • Ar and Ar′ are independently at each instance an aromatic ring system having 6 to 40 ring atoms or a heteroaromatic ring system having 7 to 40 ring atoms, where carbazole units in the heteroaromatic ring system are excluded;

    • n at each instance is independently 0 or 1;

    • m at each instance is independently 0 or 1.





Preferably at least one Ar′ in formula (4) is a group of the following formulae (4a) or (4b)




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    • where R in formulae (4a) and (4b) is the same or different at each instance and is selected from 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 one or more nonadjacent CH2 groups may be replaced by R2C═CR2, O or S and where one or more hydrogen atoms may be replaced by D, F, or CN and where two R may form a cyclic or polycyclic ring and * denotes the attachment to the remainder of the formula (4).





Preferred monoamines which are used in accordance with the invention in the organic layer of the device of the invention are described in table 5.









TABLE 5









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Preferred hole transport materials further include in combination with the compounds of table 5 or as alternatives for compounds of the table 5 materials that may be used in a hole transport, hole injection or electron blocker layer, such as indenofluorenamine derivatives, hexaazatriphenylene derivatives, monobenzoindenofluorenamines, dibenzoindenofluorenamines, dihydroacridine derivatives.


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/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.


The organic electroluminescent device of the invention may contain two or more emitting layers. At least one of the emitting layers is the light-emitting layer of the invention containing at least one compound of the formula (1) as host material 1 and at least one compound of the formula (2) as host material 2 as described above. It is particularly preferable when these emission layers in this case altogether exhibit a plurality of emission maxima between 380 nm and 750 nm, so that altogether white emission results. It should be noted that, for the production of white light, rather than a plurality of colour-emitting emitter compounds, an emitter compound used individually which emits over a broad wavelength range may also be suitable.


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 aluminium 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/Ni/NiOx, Al/PtOx) 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 vapour deposition in vacuum sublimation systems at an initial pressure of less than 10-5 mbar, preferably less than 10-6 mbar. In this case, however, it is also possible that the initial pressure is even lower, for example less than 10-7 mbar.


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


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 vapour 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 vapour 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 vapour-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 vapour 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 invention accordingly further provides a process for producing the device of the invention, characterized in that the at least one compound of the formula (1) as described above or described as preferred and the at least one compound of the formula (2) as described above or described as preferred are deposited from the gas phase successively or simultaneously from at least two material sources, optionally with the at least one phosphorescent emitter as described above or described as preferred, and form the light-emitting layer.


In a preferred embodiment of the present invention, the light-emitting layer is applied by means of gas phase deposition, wherein the constituents of the composition are premixed and evaporated from a single material source.


The invention accordingly further provides a process for producing the device of the invention, characterized in that the at least one compound of the formula (1) and the at least one compound of the formula (2) are deposited from the gas phase as a mixture, successively or simultaneously with the at least one phosphorescent emitter, and form the light-emitting layer.


The invention further provides a process for producing the device of the invention, as described above or described as preferred, characterized in that the at least one compound of the formula (1) and the at least one compound of the formula (2), as described above or described as preferred, are applied from solution together with the at least one phosphorescent emitter in order to form the light-emitting layer.


The devices of the invention feature the following surprising advantages over the prior art:


The use of the described material combination of host materials 1 and 2, as described above, especially leads to an increase in the lifetime of the devices.


As apparent in the example given hereinafter, it is possible to determine by comparison of the data for OLEDs with combinations from the prior art that the inventive combinations of matrix materials in the EML lead to devices having a significantly increased lifetime, irrespective of the emitter concentration.


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 more detail by the examples which follow, without any intention of restricting it thereby.


EXAMPLES

General Methods:


In all quantum-chemical calculations, the Gaussian16 (Rev. B.01) software package is used. The neutral singlet ground state is optimized at the B3LYP/6-31G(d) level. HOMO and LUMO values are determined at the B3LYP/6-31G(d) level for the B3LYP/6-31G(d)-optimized ground state energy. Then TD-DFT singlet and triplet excitations (vertical excitations) are calculated by the same method (B3LYP/6-31G(d)) and with the optimized ground state geometry. The standard settings for SCF and gradient convergence are used.


From the energy calculation, the HOMO is obtained as the last orbital occupied by two electrons (alpha occ. eigenvalues) and LUMO as the first unoccupied orbital (alpha virt. eigenvalues) in Hartree units, where HEh and LEh represent the HOMO energy in Hartree units and the LUMO energy in Hartree units respectively. This is used to determine the HOMO and LUMO value in electron volts, calibrated by cyclic voltammetry measurements, as follows:





HOMOcorr=0.90603*HOMO−0.84836





LUMOcorr=0.99687*LUMO−0.72445


The triplet level T1 of a material is defined as the relative excitation energy (in eV) of the triplet state having the lowest energy which is found by the quantum-chemical energy calculation.


The singlet level S1 of a material is defined as the relative excitation energy (in eV) of the singlet state having the second-lowest energy which is found by the quantum-chemical energy calculation.


The energetically lowest singlet state is referred to as S0.


The method described herein is independent of the software package used and always gives the same results. Examples of frequently utilized programs for this purpose are “Gaussian09” (Gaussian Inc.) and Q-Chem 4.1 (Q-Chem, Inc.). In the present case, the energies are calculated using the software package “Gaussian16 (Rev. B.01)”.


Example 1: Production of the OLEDs

Pretreatment for production of the OLEDs: Glass plates coated with structured ITO (indium tin oxide) of thickness 50 nm are treated prior to coating, first with an oxygen plasma, followed by an argon plasma. These plasma-treated glass plates form the substrates to which the OLEDs are applied.


The OLEDs basically have the following layer structure: substrate/hole injection layer (HIL)/hole transport layer (HTL)/electron blocker layer (EBL)/emission layer (EML)/optional hole blocker layer (HBL)/electron transport layer (ETL)/optional electron injection layer (EIL) and finally a cathode. The cathode is formed by an aluminium layer of thickness 100 nm.


All materials are applied by thermal vapour deposition in a vacuum chamber. In this case, the emission layer always consists of at least one matrix material (host material), for the purposes of the invention at least two matrix materials and an emitting dopant (emitter) which is added to the matrix material(s) in a particular proportion by volume by co-evaporation. Analogously, the electron transport layer may also consist of a mixture of two materials.


The OLEDs are characterized in a standard manner. For this purpose, the electroluminescence spectra and current-voltage-luminance characteristics (IUL characteristics) are measured. EQE and current efficiency SE (in cd/A) are calculated therefrom. SE is calculated assuming Lambertian emission characteristics.


The lifetime LT is defined as the time after which the luminance drops from a starting luminance L0 (in cd/m2) to a certain proportion L1 (in cd/m2) in the course of operation with constant current density j0 in mA/cm2. A figure of L1/L0=80% in table 7 means that the lifetime reported in the LT column corresponds to the time (in h) after which the luminance falls to 80% of its starting value (L0).


Use of Mixtures of the Invention in OLEDs


Examples V1 to V15, V15a, V16 to V18 and V18a and B1 to B30 below (see tables 6 and 7) present the use of the inventive material combinations in OLEDs compared to material combinations from the prior art. The material combinations of the invention can be used in the emission layer in phosphorescent green OLEDs.


The construction of the OLEDs is apparent from table 6. The materials required for production of the OLEDs are shown in table 8 if not already described above. The device data of the OLEDs are listed in table 7.


Details given in such a form as VG1:H2:TEG1 (33%:60%:7%) 30 nm indicate the presence of comparative material 1 (VG1) in a proportion by volume of 33% as host material 1, compound H2 as host material 2 in a proportion of 60%, and TEG1 in a proportion of 7% in a layer of thickness 30 nm.


Examples V1 to V15, V17 and V18 are comparative examples with an electron-transporting host according to the prior art or, in V15a and V16, with an electron-transporting host according to the prior art in combination with the host H0 and, in V18a, with the host HA. Examples B1 to B30 use inventive material combinations in the EML.


On comparison of the inventive examples with the corresponding comparative examples, it is clearly apparent that the inventive examples each show a distinct advantage in device lifetime.
















TABLE 6






HIL
HTL
EBL
EML
HBL
ETL
EIL


Ex.
Thickness
Thickness
Thickness
Thickness
Thickness
Thickness
Thickness







V1
SpMA1:P
SpMA1
SpMA2
VG1:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








B1
SpMA1:P
SpMA1
SpMA2
E1:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








V2
SpMA1:P
SpMA1
SpMA2
VG2:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








B2
SpMA1:P
SpMA1
SpMA2
E2:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








V3
SpMA1:P
SpMA1
SpMA2
VG3:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








B3
SpMA1:P
SpMA1
SpMA2
E4:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








V4
SpMA1:P
SpMA1
SpMA2
VG4:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








B4
SpMA1:P
SpMA1
SpMA2
E5:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








V5
SpMA1:P
SpMA1
SpMA2
VG5:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








B5
SpMA1:P
SpMA1
SpMA2
E11:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








V6
SpMA1:P
SpMA1
SpMA2
VG6:H1:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








B6
SpMA1:P
SpMA1
SpMA2
E19:H1:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








V7
SpMA1:P
SpMA1
SpMA2
VG7:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








B7
SpMA1:P
SpMA1
SpMA2
E14:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








V8
SpMA1:P
SpMA1
SpMA2
VG8:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








B8
SpMA1:P
SpMA1
SpMA2
E1:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








V9
SpMA1:P
SpMA1
SpMA2
VG9:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








B9
SpMA1:P
SpMA1
SpMA2
E12:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








V10
SpMA1:P
SpMA1
SpMA2
VG10:H2:TEG
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
1
10 nm
(50%:50%)
1 nm



(95%:5%)


(33%:60%:7%)

30 nm




20 nm


30 nm





B10
SpMA1:P
SpMA1
SpMA2
E14:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








V11
SpMA1:P
SpMA1
SpMA2
VG11:H1:TEG
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
1
10 nm
(50%:50%)
1 nm



(95%:5%)


(46%:47%:7%)

30 nm




20 nm


30 nm





B11
SpMA1:P
SpMA1
SpMA2
E1:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








V12
SpMA1:P
SpMA1
SpMA2
VG12:H23:TE
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
G1
10 nm
(50%:50%)
1 nm



(95%:5%)


(33%:60%:7%)

30 nm




20 nm


30 nm





B12
SpMA1:P
SpMA1
SpMA2
E1:H23:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








V13
SpMA1:P
SpMA1
SpMA2
VG13:H1:TEG
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
1
10 nm
(50%:50%)
1 nm



(95%:5%)


(33%:60%:7%)

30 nm




20 nm


30 nm





B13
SpMA1:P
SpMA1
SpMA2
E15:H1:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








V14
SpMA1:P
SpMA1
SpMA2
VG14:H2:TEG
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
1
10 nm
(50%:50%)
1 nm



(95%:5%)


(33%:60%:7%)

30 nm




20 nm


30 nm





B14
SpMA1:P
SpMA1
SpMA2
E17:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








V15
SpMA1:P
SpMA1
SpMA2
VG15:H2:TEG
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
1
10 nm
(50%:50%)
1 nm



(95%:5%)


(33%:60%:7%)

30 nm




20 nm


30 nm





V15a
SpMA1:P
SpMA1
SpMA2
VG15:HO:TEG
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
1
10 nm
(50%:50%)
1 nm



(95%:5%)


(33%:60%:7%)

30 nm




20 nm


30 nm





B15
SpMA1:P
SpMA1
SpMA2
E1:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








V16
SpMA1:P
SpMA1
SpMA2
VG16:HO:TEG
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
1
10 nm
(50%:50%)
1 nm



(95%:5%)


(33%:60%:7%)

30 nm




20 nm


30 nm





B16
SpMA1:P
SpMA1
SpMA2
E20:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm 2
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








V17
SpMA1:P
SpMA1
SpMA2
VG17:H2:TEG
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
1
10 nm
(50%:50%)
1 nm



(95%:5%)


(33%:60%:7%)

30 nm




20 nm


30 nm





B17
SpMA1:P
SpMA1
SpMA2
E13:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm








V18
SpMA1:P
SpMA1
SpMA2
VG18:H2:TEG
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
1
10 nm
(50%:50%)
1 nm



(95%:5%)


(33%:60%:7%)

30 nm




20 nm


30 nm





V18a
SpMA1:P
SpMA1
SpMA2
VG18:HA:TEG
ST2
ST2:LiQ
LiQ



D1


1
10 nm
(50%:50%)




(95%:5%)
215 nm
20 nm
(33%:60%:7%)

30 nm
1 nm



20 nm


30 nm





B18
SpMA1:P
SpMA1
SpMA2
E18:H2:TEG1
ST2
ST2:LiQ
LiQ



D1
215 nm
20 nm
(33%:60%:7%)
10 nm
(50%:50%)
1 nm



(95%:5%)


30 nm

30 nm




20 nm
















TABLE 7







Data of the OLEDs


















CIE x/y
j0





U1000
SE1000
EQE1000
at 1000
(mA/
L1
LT


Ex.
(V)
(cd/A)
(%)
cd/m2
cm2)
(%)
(h)

















V1
3.5
67
18
0.33/0.63
20
80
360


B1
3.3
76
19
0.35/0.62
20
80
620


V2
3.6
71
16
0.34/0.61
20
80
340


B2
3.2
72
19
0.32/0.62
20
80
630


V3
3.8
69
17
0.35/0.62
20
80
345


B3
3.4
72
18.5
0.33/0.63
20
80
600


V4
3.5
68
18
0.32/0.62
20
80
380


B4
3.2
70
18
0.34/0.61
20
80
595


V5
3.7
71
17
0.34/0.61
20
80
375


B5
3.5
75
18
0.33/0.63
20
80
590


V6
3.5
70
17
0.35/0.62
20
80
380


B6
3.3
75
18
0.33/0.63
20
80
585


V7
3.5
68
18
0.33/0.63
20
80
375


B7
3.2
75
18.5
0.33/0.63
20
80
615


V8
3.4
70
17
0.34/0.61
20
80
325


B8
3.3
76
19
0.35/0.62
20
80
620


V9
3.7
69
16.5
0.35/0.62
20
80
310


B9
3.3
75
17.5
0.33/0.63
20
80
515


V10
3.4
67
18.5
0.32/0.62
20
80
395


B10
3.2
75
18.5
0.33/0.63
20
80
615


V11
3.2
74
20.1
0.32/0.63
20
80
650


B11
3.3
76
19
0.35/0.62
20
80
620


V12
3.9
67
16
0.35/0.62
20
80
290


B12
3.3
76
19
0.35/0.62
20
80
620


V13
3.8
70
17
0.34/0.61
20
80
280


B13
3.5
76
18
0.35/0.62
20
80
610


V14
4.1
69
16
0.35/0.62
20
80
170


B14
3.4
76
18.5
0.34/0.61
20
80
570


V15
3.6
70
16
0.34/0.61
20
80
310


V15a
3.5
68
18.5
0.32/0.62
20
80
390


B15
3.3
76
19
0.33/0.63
20
80
620


V16
3.4
70
18
0.34/0.61
20
80
394


V16a
3.6
70
17
0.33/0.63
20
80
315


B16
3.3
70
17.5
0.34/0.61
20
80
575


V17
3.6
73
16.5
0.35/0.61
20
80
320


17
3.4
76
18.5
0.35/0.62
20
80
575


V18
3.5
73
18.5
0.35/0.61
20
80
365


V18a
3.4
68
18
0.32/0.62
20
80
310


B18
3.4
76
18.5
0.33/0.63
20
80
595


B19
3.4
76
18
0.33/0.63
20
80
595


B20
3.5
67
18.5
0.34/0.61
20
80
610


B21
3.5
71
17
0.35/0.63
20
80
555


B22
3.4
72
17.5
0.35/0.61
20
80
545


B23
3.5
69
18
0.34/0.62
20
80
615


B24
3.4
67
17
0.33/0.63
20
80
545


B25
3.6
76
17.5
0.35/0.62
20
80
565


B26
3.3
72
18
0.35/0.63
20
80
625


B27
3.3
71
18.5
0.34/0.62
20
80
630


B28
3.1
69
19
0.34/0.62
20
80
635


B29
3.2
67
19
0.34/0.61
20
80
630


B30
3.1
68
18
0.34/0.61
20
80
630
















TABLE 8





Materials used, if not already described:









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PD1 (1224447-88-4)







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SpMA1







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SpMA2







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SpMA5







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ST2







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LiQ







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TEG1







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TEG2







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TEG3







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H0







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HA [WO20067657]







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VG1 [KR2018010165]







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VG2 [KR2018010165]







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VG3 [KR2018010165]







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VG4 [KR20170113320]







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VG5 [KR2018010165]







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VG6 [WO19059577]







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VG7 [WO19229584]







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VG8 [WO15105315]







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VG9 [WO15105315]







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VG10 [WO19229583]







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VG11 [WO2015169412]







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VG12 [WO15105315]







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VG13 [US2016072078]







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VG14 [WO17109637]







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VG15 [WO17186760]







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VG16 [WO18060307]







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VG17 [US20200010476]







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VG18 [WO20067657]









Example 2: Synthesis of Host Materials and Precursors Thereof

The syntheses which follow, unless stated otherwise, are conducted under a protective gas atmosphere in dried solvents. The compounds of the invention can be prepared by means of synthesis methods known to those skilled in the art.


a) 2-Chloro-4,8-diphenylbenzofuro[3,2-d]pyrimidine



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31.4 g (100 mmol) of 2,4-dichloro-8-phenylbenzofuro[3,2-d]pyrimidine, 12.2 g (100 mmol) of phenylboronic acid and 11.8 g (111 mmol) of sodium carbonate are dissolved in 800 ml of 1,4-dioxane, 800 ml water and 250 ml of toluene, and stirred under an argon atmosphere. 1.2 g (1 mmol) of tetrakis(triphenylphosphine)palladium is added to the flask. The reaction mixture is stirred under reflux overnight. After cooling, the mixture is quenched. The organic phase is separated, washed three times with 300 ml of water, dried over MgSO4 and filtered, and the solvent is removed under reduced pressure. The residue is purified by column chromatography using silica gel (eluent: DCM/heptane (1:10)). The yield is 28 g (80 mmol), corresponding to 80% of theory.


The following compounds are prepared in an analogous manner:

















Reactant 1
Reactant 1
Product
Yield







1a


embedded image

  [1835207-37-8]



embedded image

  [162607-19-4]



embedded image


75%





2a


embedded image

  [1835207-37-8]



embedded image

  [395087-89-5]



embedded image


73%





3a


embedded image

  [2201128-35-8]



embedded image

  [108847-20-7]



embedded image


67%





4a


embedded image




embedded image




embedded image


80%





5a


embedded image

  [2201128-36-9]



embedded image

  [402936-15-6]



embedded image


73%





6a


embedded image




embedded image




embedded image


86%





7a


embedded image

  [1835207-37-8]



embedded image

  [5122-94-1]



embedded image


84%





8a


embedded image

  [2201128-28-9]



embedded image

  [162607-19-4]



embedded image


76%





9a


embedded image

  [2201128-33-6]



embedded image

  [395087-89-5]



embedded image


73%





10a


embedded image

  [2219361-31-4]



embedded image

  [162607-19-4]



embedded image


79%





11a


embedded image

  [2201128-2-2]



embedded image

  [162607-19-4]



embedded image


81%





12a


embedded image

  [2219361-27-8]



embedded image

  [162607-19-4]



embedded image


76%





13a


embedded image

  [2201128-28-9]



embedded image




embedded image


75%








[2201128-28-9]






14a


embedded image

  [2201128-35-8]



embedded image




embedded image


77%





15a


embedded image




embedded image




embedded image


81%





16a


embedded image

  [2219361-31-4]



embedded image

  [100124-06-9]



embedded image


63%





17a


embedded image

  [1835207-37-8]



embedded image

  [100124-06-9]



embedded image


82%





18a


embedded image

  [2201128-36-9]



embedded image

  [2412400-98-5]



embedded image


64%





19a


embedded image




embedded image




embedded image


84%





20a


embedded image

  [1835207-37-8]



embedded image

  [162607-19-4]



embedded image


74%





21a


embedded image

  [2201128-28-9]



embedded image




embedded image


62%





22a


embedded image

  [1169560-03-5]



embedded image

  [1307859-67-1]



embedded image


65%





23a


embedded image




embedded image

  [1307859-67-1]



embedded image


72%





24a


embedded image




embedded image

  [395087-89-5]



embedded image


65%





25a


embedded image

  [2201128-38-1]



embedded image




embedded image


56%





26a


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embedded image

  [395087-89-5]



embedded image


77%





27a


embedded image

  [1835207-37-8]



embedded image




embedded image


65%









b) 4,8-Diphenyl-2-[8-(9-phenylcarbazol-3-yl)dibenzofuran-1-yl]benzofuro[3,2-d]pyrimidine



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35.6 g (100 mmol) of 2-chloro-4,8-diphenylbenzofuro[3,2-d]pyrimidine, 54.2 g (100 mmol) of [8-(9-phenylcarbazol-3-yl)dibenzofuran-1-yl]boronic acid and 11.8 g (111 mmol) of sodium carbonate are dissolved in 800 ml of 1,4-dioxane, 800 ml water and 250 ml of toluene, and stirred under an argon atmosphere. 1.2 g (1 mmol) of tetrakis(triphenylphosphine)palladium is added to the flask. The reaction mixture is stirred under reflux overnight. After cooling, the mixture is quenched. The organic phase is separated, washed three times with 300 ml of water, dried over MgSO4 and filtered, and the solvent is removed under reduced pressure. The residue is purified by column chromatography using silica gel (eluent: DCM/heptane (1:10)). The yield is 51 g (71 mmol), corresponding to 71% of theory.


The following compounds are prepared in an analogous manner:

















Reactant 1
Reactant 2
Product
Yield







1b


embedded image

  [1822311-33-0]



embedded image

  [2201128-28-9]



embedded image


72%





2b


embedded image

  [1822311-32-9]



embedded image

  [2268732-49-4]



embedded image


75%





3b


embedded image

  [1822311-32-9]



embedded image




embedded image


70%








E25






4b


embedded image

  [1822311-32-9]



embedded image




embedded image


68%








E5






5b


embedded image

  [1822311-32-9]



embedded image




embedded image


67%





6b


embedded image

  [1822311-32-9]



embedded image

  [2268733-22-6]



embedded image


82%








E27






7b


embedded image




embedded image

  [2201128-28-9]



embedded image


73%






[2096512-72-8]








8b


embedded image

  [1582802-05-8]



embedded image

  [2201128-28-9]



embedded image


79%





9b


embedded image




embedded image




embedded image


69%





11b


embedded image




embedded image




embedded image


76%





12b


embedded image

  [1307793-77-6]



embedded image

  [2201128-28-9]



embedded image


74%





13b


embedded image

  [2411332-76-6]



embedded image

  [2201128-28-9]



embedded image


77%





14b


embedded image

  [1427560-52-8]



embedded image




embedded image


81%








E26






15b


embedded image

  [1822320-55-7]



embedded image




embedded image


80%








E6






16b


embedded image




embedded image




embedded image


83%






[2412401-01-3]








17b


embedded image

  1822311-38-5]



embedded image




embedded image


78%








E24






18b


embedded image

  [2392930-01-5]



embedded image




embedded image


81%








E4






19b


embedded image

  [1779497-51-6]



embedded image




embedded image


80%





20b


embedded image

  [1822320-55-7]



embedded image




embedded image


79%








E2






21b


embedded image

  [1822311-30-7]



embedded image




embedded image


76%








E23






22b


embedded image

  [1822311-30-7]



embedded image




embedded image


65%








E7






23b


embedded image

  [1822320-55-7]



embedded image




embedded image


78%








E22






24b


embedded image

  [1822320-55-7]



embedded image




embedded image

  E9

68%





25b


embedded image

  [1822311-30-7]



embedded image




embedded image


67%





26b


embedded image

  [1822311-33-0]



embedded image

  [2201128-28-9]



embedded image


81%





27b


embedded image

  [1822311-30-7]



embedded image

  [2201128-28-9]



embedded image


76%








E10






28b


embedded image

  [1822320-55-7]



embedded image

  [2201128-28-9]



embedded image


79%








E8






29b


embedded image




embedded image




embedded image


81%








E3






30b


embedded image

  [1822311-35-2]



embedded image




embedded image


70%








E11






31b


embedded image




embedded image

  [2411326-31-1]



embedded image


75%





32b


embedded image




embedded image

  [2411326-31-1]



embedded image

  E12

66%





33b


embedded image




embedded image




embedded image

  E13

69%





34b


embedded image




embedded image

  [1822311-30-7]



embedded image


68%








E14






35b


embedded image




embedded image

  [1822311-30-7]



embedded image


64%








E15






36b


embedded image




embedded image

  [1822311-30-7]



embedded image


63%








E16






37b


embedded image




embedded image

  [1822320-55-7]



embedded image


72%








E17






38b


embedded image




embedded image




embedded image

  E18

70%





39b


embedded image




embedded image

  [1822320-55-7]



embedded image


73%








E19






40b


embedded image




embedded image

  [1582802-05-8 ]



embedded image


76%








E20








Claims
  • 1.-15. (canceled)
  • 16. An organic electroluminescent device comprising an anode, a cathode and at least one organic layer containing at least one light-emitting layer, wherein the at least one light-emitting layer contains at least one compound of the formula (1) as host material 1 and at least one compound of the formula (2) as host material 2,
  • 17. The organic electroluminescent device according to claim 16, characterized in that the host material 1 conforms to the formula (1a)
  • 18. The organic electroluminescent device according to claim 16, characterized in that V1 is O or NA.
  • 19. The organic electroluminescent device according to claim 16, characterized in that the host material 2 conforms to one of the formulae (2a), (2b) and (2c)
  • 20. The organic electroluminescent device according to claim 16, wherein the organic electroluminescent device is selected from the group consisting of organic light-emitting transistors (OLETs), organic field quench devices (OFQDs), organic light-emitting electrochemical cells (OLECs, LECs, LEECs), organic laser diodes (O-lasers) and organic light-emitting diodes (OLEDs).
  • 21. The organic electroluminescent device according to claim 16, characterized in that this organic layer comprises, in addition to the light-emitting layer (EML), a hole injection layer (HIL), a hole transport layer (HTL), an electron transport layer (ETL), an electron injection layer (EIL) and/or a hole blocker layer (HBL).
  • 22. The organic electroluminescent device according to claim 16, characterized in that the light-emitting layer, as well as the at least one host material 1 and the at least one host material 2, contains at least one phosphorescent emitter.
  • 23. The organic electroluminescent device according to claim 16, characterized in that 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 is a monoamine that does not contain a carbazole unit.
  • 24. A process for producing a device according to claim 16, which comprises apply the organic layer by gas phase deposition or from solution.
  • 25. The process according to claim 24, characterized in that to produce the light-emitting layer the at least one compound of the formula (1) and the at least one compound of the formula (2) are deposited from the gas phase successively or simultaneously from at least two material sources, optionally with the at least one phosphorescent emitter.
  • 26. The process according to claim 24, characterized in that to produce the light-emitting layer the at least one compound of the formula (1) and the at least one compound of the formula (2) are deposited from the gas phase as a mixture, successively or simultaneously with the at least one phosphorescent emitter.
  • 27. The process according to claim 24, characterized in that to produce the light-emitting layer the at least one compound of the formula (1) and the at least one compound of the formula (2) are applied from a solution together with the at least one phosphorescent emitter.
  • 28. A mixture comprising at least one compound of the formula (1) and at least one compound of the formula (2),
  • 29. The mixture according to claim 28, characterized in that the mixture consists of at least one compound of the formula (1), at least one compound of the formula (2) and a phosphorescent emitter.
  • 30. formulation comprising the mixture according to claim 28 and at least one solvent.
Priority Claims (1)
Number Date Country Kind
20204008.5 Oct 2020 EP regional
PCT Information
Filing Document Filing Date Country Kind
PCT/EP2021/079450 10/25/2021 WO