ORGANIC ELECTROLUMINESCENT DEVICE

Description

Subject of the invention

[0001] 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, as well as a formulation comprising a mixture of the host materials and a mixture comprising the host materials. The electron-transporting host material corresponds to a compound of formula (1) containing diazadibenzofuran or diazadibenzothiophene units. The hole-transporting host material corresponds to a compound of formula (2) from the class of biscarbazoles or derivatives thereof. Background of the invention

[0002] The construction of organic electroluminescent devices (e.g., OLEDs - organic light-emitting diodes or OLECs - organic light-emitting electrochemical cells), which use organic semiconductors as functional materials, has long been known. In addition to fluorescent emitters, organometallic complexes that exhibit phosphorescence instead of fluorescence are increasingly being used as emitting materials. For quantum mechanical reasons, the use of organometallic compounds as phosphorescence emitters allows for up to fourfold increases in energy and power efficiency. However, there is still room for improvement in OLEDs in general, and especially in OLEDs that exhibit triplet emission (phosphorescence), for example, with regard to efficiency, operating voltage, and lifetime.

[0003] The properties of organic electroluminescent devices are not only determined by the emitters used. The other materials used, such as host and matrix materials, hole-blocking materials, electron-transport materials, hole-transport materials, and electron- or exciton-blocking materials, are also of particular importance, especially the host and matrix materials. Improvements to these materials can lead to significant improvements in electroluminescent devices.

[0004] Host materials for use in organic electronic devices are well known to those skilled in the art. In the prior art, the term "matrix material" is often used to refer to a host material for phosphorescent emitters. This use of the term also applies to the present invention. A variety of host materials have now been developed for both fluorescent and phosphorescent electronic devices.

[0005] Another possibility to improve the performance of electronic devices, in particular organic electroluminescent devices, is to use combinations of two or more materials, in particular host materials or matrix materials.

[0006] US 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. Using this mixture, the lifetime of the OLED could be improved compared to the prior art.

[0007] US Pat. No. 6,803,720 B1 discloses the use of a mixture containing a phosphorescent emitter and a hole- and electron-transport material in the emission layer of an OLED. Both the hole- and electron-transport materials are small organic molecules.

[0008] WO15105313, US2016308142 and US2016308143 describe, inter alia, diazadibenzofuran compounds and diazadibenzothiophene compounds as host material and describe their use in an organic electroluminescent device, optionally in combination with another host material.

[0009] KR 2016 0046077 A, KR 2016 0046078 A, and US 2016 / 072078 A1 describe diazadibenzothiophene compounds as host material and their use in an organic electroluminescent device, optionally in combination with another host material.

[0010] WO17186760 describes diazacarbazole compounds and their use in an organic electroluminescent device as host material, electron transport material and hole blocking material.

[0011] In WO18060218 diazadibenzofuran compounds or

[0012] Diazadibenzothiophene compounds and their use in an organic electroluminescent device are disclosed, wherein the benzothienopyrimidine compounds and benzofuropyrimidine compounds each carry at least one substituent containing a carbazole unit bonded via N.

[0013] WO18234926 and WO18234932 disclose specific diazadibenzofuran compounds and diazadibenzothiophene compounds, respectively, and their use in an organic electroluminescent device.

[0014] WO18060307 discloses diazadibenzofuran compounds or diazadibenzothiophene compounds and their use in an organic electroluminescent device.

[0015] US2018155325 and US2018182976 describe specific azadibenzofuran compounds and azadibenzothiophene compounds, respectively, as host material for organic electroluminescent devices, optionally in combination with another host material.

[0016] KR20180022562 describes specifically substituted benzocarbazole compounds and their use as host material together in an organic electroluminescent device.

[0017] KR20180041607 discloses diazadibenzofuran compounds or diazadibenzothiophene compounds and their use in an organic electroluminescent device.

[0018] WO19059577 and WO19017741 describe diazadibenzofuran and diazadibenzothiophene derivatives that can be used as host materials in an electroluminescent device.

[0019] WO19240473 describes special triphenylene derivatives that can be used as host materials in an electroluminescent device.

[0020] WO19083327 describes special benzocarbazole derivatives that can be used as host materials in an electroluminescent device.

[0021] US2020161564 discloses diazadibenzofuran compounds or diazadibenzothiophene compounds and their use in an organic electroluminescent device.

[0022] WO20067657 describes a composition of materials and their use in optoelectronic devices.

[0023] WO20071778 discloses specific diazadibenzofuran compounds or diazadibenzothiophene compounds, their composition with other materials and their use in an organic electroluminescent device.

[0024] KR2018010166 and KR20200021304 disclose specific diazadibenzofuran compounds and diazadibenzothiophene compounds, respectively, and their use in an organic electroluminescent device.

[0025] However, there is still room for improvement when using these materials or when using mixtures of the materials, particularly with regard to efficiency, operating voltage and / or lifetime of the organic electroluminescent device.

[0026] The object of the present invention is therefore to provide a combination of host materials which are suitable for use in an organic electroluminescent device, in particular in a fluorescent or phosphorescent OLED, and which lead to good device properties, in particular with regard to an improved lifetime, as well as to provide the corresponding electroluminescent device. Summary of the invention

[0027] It has now been found that the combination of at least one compound of the formula (1) as the first host material and at least one hole-transporting compound of the formula (2) as the second host material in a light-emitting layer of an organic electroluminescent device solves this problem and eliminates the disadvantages of the prior art. The use of such a material combination for producing the light-emitting layer in an organic electroluminescent device leads to very good properties of these devices, in particular with regard to lifetime, in particular with the same or improved efficiency and / or operating voltage. The advantages are also apparent in particular in the presence of a light-emitting component in the emission layer, in particular in combination with emitters of the formulas (3a) or (3b) or emitters of the formulas (I) to (VI) at concentrations between 2 and 15 wt.-%, or in combination with monoamines of formula (4) in the hole injection layer and / or hole transport layer.

[0028] A first subject of the present invention is therefore 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 formula (1) as host material 1 and at least one compound of formula (2) as host material 2, where the symbols and indices used are: Ring A 1 in formula (1) corresponds to formula (1A) V 2 is O or S; Ring A 2 in formula (1) corresponds to one of the formulas (1B), (1C), (1D), (1E), (1F), (1G) or (1H), which may be substituted by one or more radicals R; V 3 is O or S, Rx, Ry and Rz are each independently an aromatic ring system having 6 to 14 ring atoms or a heteroaromatic ring system having 9 to 14 ring atoms, each of which may be substituted by one or more radicals R; n is 0, 1, 2 or 3; m is 0, 1, 2, 3 or 4; o is 0, 1 or 2; p1, p2 are 0 or 1 and the sum of p1 + p2 is 1; R# is independently D at each occurrence, an aryl group having 6 to 12 C atoms which may be substituted by one or more radicals R, dibenzofuranyl, dibenzothienyl or carbazolyl bonded via a C atom which may be substituted by one or more radicals R and wherein the N atom of the carbazolyl group is substituted by an aryl group having 6 to 12 C atoms which may be substituted by one or more radicals R;R* is on each occurrence, independently D or an aryl group having 6 to 12 C atoms which may be substituted by one or more radicals R; R is on each occurrence, identically or differently selected from D, F, CN, a straight-chain alkyl group having 1 to 20 C atoms, a branched or cyclic alkyl group having 3 to 20 C atoms, where one or more non-adjacent CH 2 groups may be replaced by R 2< C=CR 2< , O or S and where one or more H atoms may be replaced by D, F or CN or an aryl group having 6 to 14 C atoms; R 2< is selected, identically or differently at each occurrence, from the group consisting of H, D, F, CN, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where one or more non-adjacent CH 2 groups may be replaced by O or S and where one or more H atoms may be replaced by D, F, or CN;K, M are each independently of one another an unsubstituted or partially or fully deuterated or simply substituted by R 1< aromatic ring system having 6 to 40 ring atoms, when x and y are 0 and when x 1 and y 1 are 0, or K, M each independently of one another together with X or X 1< form a heteroaromatic ring system having 14 to 40 ring atoms, as soon as the value of x, x1, y and / or y1 is 1; x, x1 are each independently on each occurrence 0 or 1; y, y1 are each independently on each occurrence 0 or 1; X and X 1< are each independently on each occurrence a bond or C(R +< ) 2 ; R 0< is, at each occurrence, independently of one another, an unsubstituted or partially or fully deuterated aromatic ring system having 6 to 18 ring atoms or two substituents R 0< can form a ring of the formula (1D); R 1< is an aryl group having 6 to 18 C atoms;R +< is at each occurrence independently a straight-chain or branched alkyl group having 1 to 4 C atoms and c, d, e and f are independently 0, 1 or 2. ;

[0029] The invention further provides a process for producing the organic electroluminescent devices and mixtures comprising at least one compound of formula (1) and at least one compound of formula (2), specific material combinations and formulations comprising such mixtures or material combinations. The corresponding preferred embodiments, as described below, are also subject of the present invention. The surprising and advantageous effects are achieved by specifically selecting the compounds of formula (1) and the compounds of formula (2). The surprising and advantageous effects are achieved by specifically selecting the compounds of formula (1) and the compounds of formula (2), preferably together with specific emitters in the light-emitting layer and / or with specific monoamines in the hole injection and / or hole transport layer. Detailed description of the invention

[0030] The organic electroluminescent device according to 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 according to the invention is, in particular, an organic light-emitting diode or an organic light-emitting electrochemical cell. The device according to the invention is particularly preferably an OLED.

[0031] The organic layer of the device according to the invention, which contains the light-emitting layer comprising the material combination of at least one compound of formula (1) and at least one compound of formula (2), as described above or below, preferably contains, 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-blocking layer (HBL). The device according to the invention can also contain several layers from this group selected from EML, HIL, HTL, ETL, EIL, and HBL.

[0032] However, the device can also contain inorganic materials or layers that are made entirely of inorganic materials.

[0033] It is preferred that the organic layer of the device according to the invention contains a hole-injection layer and / or the hole-transport layer whose hole-injecting material and hole-transporting material are a monoamine that does not contain a carbazole moiety. A suitable selection of monoamine compounds and preferred monoamines are described below.

[0034] It is preferred that the light-emitting layer comprising at least one compound of formula (1) and at least one compound of formula (2) is a phosphorescent layer characterized in that, in addition to the host material combination of compounds of formula (1) and formula (2), as described above, it contains at least one phosphorescent emitter. A suitable selection of emitters and preferred emitters are described below.

[0035] An aryl group within the meaning of this invention contains 6 to 18 aromatic C atoms. A heteroaryl group within the meaning of this invention contains 5 to 40 aromatic ring atoms, where the ring atoms comprise C atoms and at least one heteroatom, with the proviso that the sum of C atoms and heteroatoms is at least 5. The heteroatoms are preferably selected from N, O and / or S. An aryl group or heteroaryl group is understood to be 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 with 6 to 18 C atoms is therefore preferably phenyl, naphthyl, phenanthryl or triphenylenyl, whereby the attachment of the aryl group as a substituent is not restricted.The aryl or heteroaryl group in the sense of this invention may carry one or more radicals R, wherein the substituent R is described below.

[0036] An aromatic ring system within the meaning of this invention contains 6 to 40 ring atoms, preferably carbon atoms. The aromatic ring system also includes aryl groups, as described above.

[0037] A heteroaromatic ring system within the meaning of this invention contains 5 to 40 ring atoms and at least one heteroatom. A preferred heteroaromatic ring system has 9 to 14 ring atoms or 14 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.

[0038] An aromatic or heteroaromatic ring system within the meaning of this invention is understood to mean a system which does not necessarily contain only aryl or heteroaryl groups, but in which several aryl or heteroaryl groups can also be interrupted by a non-aromatic unit (preferably less than 10% of the atoms other than H), such as a C atom or a carbonyl group. Thus, for example, systems such as 9,9'-spirobifluorene, 9,9-diarylfluorene or 9,9-dialkylfluorene are also to be understood as aromatic ring systems within the meaning of this invention, as are systems in which two or more aryl groups are interrupted, for example, by a linear or cyclic alkyl group or by a silyl group. Furthermore, systems in which two or more aryl or heteroaryl groups are directly bonded to one another, such as biphenyl, terphenyl, quaterphenyl or bipyridine, are also excluded from the definition of an aromatic or heteroaryl ring system.heteroaromatic ring system.

[0039] An aromatic or heteroaromatic ring system with 6 - 40 ring atoms, which can be linked to the aromatic or heteroaromatic ring via any position, is understood to mean, for example, groups derived from benzene, naphthalene, anthracene, benzanthracene, phenanthrene, benzophenanthrene, pyrene, chrysene, perylene, fluoranthene, benzfluoranthene, 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,Pyrazol, Indazol, Imidazol, Benzimidazol, Naphthimidazol, Phenanthrimidazol, Pyridimidazol, Pyrazinimidazol, Chinoxalinimidazol, Oxazol, Benzoxazol, Naphthoxazol, Anthroxazol, Phenanthroxazol, Isoxazol, 1,2-Thiazol, 1,3-Thiazol, Benzothiazol, Pyridazin, Benzopyridazin, Pyrimidin, Benzpyrimidin, Chinoxalin, 1,5-Diazaanthracen, 2,7-Diazapyren, 2,3-Diazapyren, 1,6-Diazapyren, 1,8-Diazapyren, 4,5-Diazapyren, 4,5,9,10-Tetraazaperylen, Pyrazin, Phenazin, Phenoxazin, Phenothiazin, Fluorubin, Naphthyridin, Azacarbazol, Benzocarbolin, Phenanthrolin, 1,2,3-Triazol, 1,2,4-Triazol, Benzotriazol, 1,2,3-Oxadiazol, 1,2,4-Oxadiazol, 1,2,5-Oxadiazol, 1,3,4-Oxadiazol, 1,2,3-Thiadiazol, 1,2,4-Thiadiazol, 1,2,5-Thiadiazol, 1,3,4-Thiadiazol, 1,3,5-Triazin, 1,2,4-Triazin, 1,2,3-Triazin, Tetrazol, 1,2,4,5-Tetrazin, 1,2,3,4-Tetrazin, 1,2,3,5-Tetrazin, Purin, Pteridin, Indolizin und Benzothiadiazol.,

[0040] An aromatic ring system having 6 to 18 ring atoms, preferably C atoms, is preferably selected from phenyl, 1,2-biphenyl, 1,3-biphenyl, 1,4-biphenyl, 9,9-dialkylfluorenyl, naphthyl, phenanthryl and triphenylenyl, which may be substituted by one or more radicals R, wherein the substituent R is described below.

[0041] A cyclic alkyl group in the sense of this invention is understood to mean a monocyclic, a bicyclic or a polycyclic group.

[0042] Im Rahmen der vorliegenden Erfindung werden unter einer geradkettigen, verzweigten oder cyclischen C 1 - bis C 20 -Alkylgruppe beispielsweise die Reste 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, neo-Pentyl, Cyclopentyl, n-Hexyl, s-Hexyl, t-Hexyl, 2-Hexyl, 3-Hexyl, neo-Hexyl, 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, Trifluormethyl, Pentafluorethyl, 2,2,2-Trifluorethyl, 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-Diethyln-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 are understood.

[0043] A phosphorescent emitter within the meaning of the present invention is a compound that exhibits luminescence from an excited state with higher spin multiplicity, i.e., a spin state > 1, in particular from an excited triplet state. For the purposes of this application, all luminescent complexes with transition metals or lanthanides are considered phosphorescent emitters. A more precise definition is provided below.

[0044] If the host materials of the light-emitting layer comprising at least one compound of formula (1), as described above or preferably described below, and at least one compound of formula (2), as described above or described below, are used for a phosphorescent emitter, it is preferred if their triplet energy is not significantly lower than the triplet energy of the phosphorescent emitter. Preferably, the triplet level T 1 (emitter) - T 1 (matrix) ≤ 0.2 eV, particularly preferably ≤ 0.15 eV, very particularly preferably ≤ 0.1 eV applies to the triplet level. T 1 (matrix) is the triplet level of the matrix material in the emission layer, this condition applying to each of the two matrix materials, and T 1 (emitter) is the triplet level of the phosphorescent emitter. If the emission layer contains more than two matrix materials, the above-mentioned relationship preferably also applies to each additional matrix material.

[0045] The following describes the host material 1 and its preferred embodiments, which are contained in the device according to the invention. The preferred embodiments of the host material 1 of formula (1) also apply to the mixture and / or formulation according to the invention.

[0046] In compounds of formula (1), ring A2 is selected from one of formulas (1B), (1C), (1D), (1E), (1F), (1G) or (1H). In compounds of formula (1), ring A2 is preferably selected from one of formulas (1B), (1C), (1D) or (1F). In compounds of formula (1), ring A2 particularly preferably corresponds to formula (1B) or formula (1D).

[0047] The Left may be substituted by one or more radicals R, where R has a meaning as described above or as preferably described below. Preferably, the linker is substituted once with a radical R or it is unsubstituted, where R has a meaning as described above or as preferably described below. The linker is particularly preferably not substituted.

[0048] The linking of the linker to the rest of formula (1) is not restricted.

[0049] Alternative links can be described by the formulas L1, L2, L3 and L4, where ring A 2 has a meaning as previously described or preferably described.

[0050] If ring A 2 corresponds to one of the formulas (1B), (1C), (1F), (1G) and (1H), the linkage L1, L2 or L3 is preferred. If ring A 2 corresponds to the formula (1B), the linkage L1 or L3 is particularly preferred or L1 is very particularly preferred. If ring A 2 corresponds to one of the formulas (1D) or (1E), the linkage L1, L3 or L4 is preferred. If ring A 2 corresponds to the formula (1D), the linkage L1 or L4 is particularly preferred or L4 is very particularly preferred.

[0051] Alternatively, if ring A2 corresponds to one of formulas (1D) or (1E), the linkage L1, L2, or L3 is preferred. If ring A2 corresponds to formula (1D), the linkage L1 or L3 is particularly preferred, or L1 is most particularly preferred.

[0052] In a preferred embodiment of the compounds of formula (1), ring A 2 corresponds to formula (1B), which may be substituted by one or more radicals R, represented as compounds of formula (1a), where the symbols R#, R*, n, m, o, p1, p2, Rx, Ry, Rz, V3, and Ring A1 have a preferred meaning as previously mentioned or hereinafter mentioned. In this embodiment, Ring A2 of formula (1B) can be formed via the linkage L1, L2, L3, or L4, as previously described.

[0053] In a preferred embodiment of the compounds of formula (1a), the substituent based on benzocarbazole is bonded in the 1- or 4-position of the dibenzofuran or dibenzothiophene, represented as compounds of formulas (1a1) or (1a2), where the symbols R#, R*, n, m, o, p1, p2, Rx, Ry, Rz, V 3 and Ring A 1 used have a preferred meaning mentioned above or mentioned below.

[0054] In a particularly preferred embodiment of the compounds of formula (1a), the substituent based on benzocarbazole is bonded in the 1-position of the dibenzofuran or dibenzothiophene and the substituent based on diazadibenzofuran or diazadibenzothiophene is bonded in the 4-position of the dibenzofuran or dibenzothiophene, represented as compounds of formula (1a3), where the symbols R#, R*, n, m, o, p1, p2, Rx, Ry, Rz, V 3 and Ring A 1 used have a preferred meaning mentioned above or mentioned below.

[0055] In a preferred embodiment of the compounds of formula (1), ring A 2 corresponds to formula (1C), which may be substituted by one or more radicals R, represented as compounds of formula (1b), where the symbols R#, R*, n, m, o, p1, p2, Rx, Ry, Rz, V3, and Ring A1 have a preferred meaning as previously mentioned or hereinafter mentioned. In this embodiment, Ring A2 of formula (1C) can be formed via the linkage L1, L2, L3, or L4, as previously described.

[0056] In a preferred embodiment of the compounds of formula (1), ring A 2 corresponds to formula (1D), which may be substituted by one or more radicals R, represented as compounds of formula (1c), where the symbols R#, R*, n, m, o, p1, p2, Rx, Ry, Rz, V3, and Ring A1 have a preferred meaning as previously mentioned or hereinafter mentioned. In this embodiment, Ring A2 of formula (1D) can be formed via the linkage L1, L2, L3, or L4, as previously described.

[0057] In a preferred embodiment of the compounds of formula (1c), the substituent based on benzocarbazole is bonded in the 1-position and the substituent based on diazadibenzofuran or diazadibenzothiophene is bonded in the 4-position of the naphthylene, or the substituent based on benzocarbazole is bonded in the 2-position and the substituent based on diazadibenzofuran or diazadibenzothiophene is bonded in the 3-position of the naphthylene, represented as compounds of formulas (1c1) or (1c2), where the symbols R#, R*, n, m, o, p1, p2, Rx, Ry, Rz, V 3 and Ring A 1 used have a preferred meaning mentioned above or mentioned below.

[0058] In a preferred embodiment of the compounds of formula (1), ring A 2 corresponds to formula (1E), which may be substituted by one or more radicals R, represented as compounds of formula (1d), where the symbols R#, R*, n, m, o, p1, p2, Rx, Ry, Rz, V3, and Ring A1 have a preferred meaning as previously mentioned or hereinafter mentioned. In this embodiment, Ring A2 of formula (1E) can be formed via the linkage L1, L2, L3, or L4, as previously described.

[0059] In a preferred embodiment of the compounds of formula (1), ring A 2 corresponds to formula (1F), which may be substituted by one or more radicals R, represented as compounds of formula (1e), where the symbols R#, R*, n, m, o, p1, p2, Rx, Ry, Rz, V3, and ring A1 have a preferred meaning as previously mentioned or hereinafter mentioned. In this embodiment, ring A2 of formula (1F) can be formed via the linkage L1, L2, L3, or L4, as previously described.

[0060] In a preferred embodiment of the compounds of formula (1), ring A 2 corresponds to formula (1G), which may be substituted by one or more radicals R, represented as compounds of formula (1f), where the symbols R#, R*, n, m, o, p1, p2, Rx, Ry, Rz, V3, and Ring A1 have a preferred meaning as previously mentioned or hereinafter mentioned. In this embodiment, Ring A2 of formula (1G) can be formed via the linkage L1, L2, L3, or L4, as previously described.

[0061] In a preferred embodiment of the compounds of formula (1), ring A 2 corresponds to formula (1H), which may be substituted by one or more radicals R, represented as compounds of formula (1g), where the symbols R#, R*, n, m, o, p1, p2, Rx, Ry, Rz, V3, and ring A1 have a preferred meaning as previously mentioned or hereinafter mentioned. In this embodiment, ring A2 of formula (1H) can be formed via the linkage L1, L2, L3, or L4, as previously described.

[0062] A further subject matter of the invention is the organic electroluminescent device as described above, wherein the host material 1 corresponds to a compound of the formulas (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) or (1g), as described above.

[0063] In compounds of formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) or (1g) the structure of the substituent is based on benzocarbazole not restricted.

[0064] Alternative substituents based on benzocarbazole are the structures of formulas BC-1, BC-2 and BC-3, where "*" means the bond to the residue of formula (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) or (1g) and R#, R*, m and o have a preferred meaning mentioned above or later.

[0065] In a preferred embodiment of the compounds of formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) or (1g) the structure BC-1 or BC-2, as previously described.

[0066] In a particularly preferred embodiment of the compounds of formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) or (1g) the structure BC-1, as previously described.

[0067] In compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1d), (1e), (1f) or (1g) or preferred compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1d), (1e), (1f) or (1g), V 3 preferably represents O.

[0068] A further subject matter of the invention is the organic electroluminescent device as described above, wherein the host material 1 corresponds to a compound of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1d), (1e), (1f) or (1g) or a preferred compound of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1d), (1e), (1f) or (1g), wherein V 3 is O.

[0069] The substituent R# in compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) and (1g) or preferably described compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) and (1g) at each occurrence independently of one another represents D, an aryl group having 6 to 12 C atoms, which may be substituted by one or more radicals R, dibenzofuranyl, dibenzothienyl or carbazolyl bonded via a C atom, which may be substituted by one or more radicals R and wherein the N atom of the carbazolyl group is substituted by an aryl group having 6 to 12 C atoms which may be substituted with one or more radicals R. The position of the attachment of the dibenzofuranyl or dibenzothienyl is not restricted.

[0070] If R# stands for D in compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) and (1g), it is preferred that m is 1, 2, 3 or 4, preferably 4 at each occurrence.

[0071] If R# represents an aryl group having 6 to 12 C atoms which may be substituted by one or more radicals R, dibenzofuranyl, dibenzothienyl or carbazolyl bonded to a C atom which may be substituted by one or more radicals R, where the N atom of the carbazolyl group is substituted by an aryl group having 6 to 12 C atoms which may be substituted by one or more radicals R, in compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) and (1g), then m at each occurrence, independently of one another, is preferably 0, 1 or 2, particularly preferably 0 or 1. The aryl group having 6 to 12 C atoms which may be substituted by one or more radicals R may be substituted is preferably phenyl, which may be substituted by one or more radicals R, where R has a meaning given above or preferably given.R# is preferably unsubstituted phenyl, dibenzofuranyl, dibenzothienyl, or N-phenylcarbazolyl, whereby the bonding of the dibenzofuranyl, dibenzothienyl, or N-phenylcarbazole is not restricted. R# is particularly preferably unsubstituted phenyl. In compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f), and (1g) or preferred compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f), and (1g), m is preferably 0 or 1, particularly preferably 0.

[0072] In compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) and (1g) or preferably described compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) and (1g), o preferably represents 0 or 1, very preferably 0.

[0073] If o is 1 or 2, then the substituent R* is independently D or an aryl group having 6 to 12 C atoms which may be substituted by one or more radicals R, where R has a meaning given above or given below as preferred. If o is 2, R* is preferably D at each occurrence. If o is 1, then the substituent R* is preferably an aryl group having 6 to 12 C atoms which may be substituted by one or more radicals R, more preferably an aryl group having 6 to 12 C atoms, most preferably unsubstituted phenyl.

[0074] The ring A 1 in the diaza substituent of formula (D) of the host material 1 of formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) and (1g), as previously described or preferably described, corresponds to formula (1A), where V 2 is O or S and "*" in formula (D) represents the bond to the remainder of formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) or (1g) of the host material 1 and Rx, Ry, Rz, p1, p2, R* and n have a meaning given previously or preferably or have a meaning given below.

[0075] Preferred embodiments of the diaza substituent of formula (D) of the host material 1 of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) and (1g), as described above or preferably described, in which V 2 is O, correspond to the formulas (D-1), (D-2), (D-3), (D-4), (D-5), (D-6), (D-7), (D-8), (D-9), (D-10), (D-11) and (D-12), where "*", Rx, Ry, Rz, R* and n have a meaning given previously or subsequently and the condition of the sum of p1+p2 = 1 has been observed.

[0076] Preferred embodiments of the diaza substituent of formula (D) of the host material 1 of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) and (1g), as described above or preferably described, in which V 2 denotes S, correspond to the formulas (D-S1), (D-S2), (D-S3), (D-S4), (D-S5), (D-S6), (D-S7), (D-S8), (D-S9), (D-S10), (D-S11) and (D-S12), where "*", Rx, Ry, Rz, R* and n have a meaning given previously or below.

[0077] Preferred embodiments of the diaza substituent of formula (D) of the host material 1 of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) and (1g), as described above or preferably described, correspond to the formulas (D-1), (D-2), (D-3), (D-4), (D-5), (D-6), (D-9), (D-10), (D-11), (D-12), (D-S1), (D-S4), (D-S5), (D-S6) and (D-S11).

[0078] Particularly preferred embodiments of the diaza substituent of formula (D) of the host material 1 of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) and (1g), as described above or preferably described, correspond to the formulas (D-1), (D-4), (D-5), (D-9), (D-10), (D-12) and (D-511).

[0079] Very particularly preferred embodiments of the diaza substituent of formula (D) of the host material 1 of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) and (1g), as described above or preferably described, correspond to the formulas (D-1), (D-4) and (D-5), particularly preferably (D-1).

[0080] In compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) and (1g) or preferably described compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) and (1g), V 2 in ring A 1 of the formula (1A) is preferably O.

[0081] A further subject matter of the invention is the organic electroluminescent device as described above, wherein the host material 1 corresponds to one of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f) and (1g), as described above or preferably described, and the diaza substituent of the formula (D) is selected from one of the formulas (D-1), (D-2), (D-3), (D-4), (D-5), (D-6), (D-7), (D-8), (D-9), (D-10), (D-11) and (D-12), (D-S1), (D-S2), (D-S3), (D-S4), (D-S5), (D-S6), (D-S7), (D-S8), (D-S9), (D-S10), (D-S11) and (D-S12) is selected as previously described.

[0082] In a preferred embodiment of the host material 1 of formula (1), as previously described or preferably described, the diaza substituent of formula (D) is selected from the formula (D-1) / (D-S1), (D-4) / D-S4) or (D-5) / (D-S5), which can be represented by the formulas (1h), (1i) and (1j), where R*, R#, m, o, n, Rx, Ry, Rz, V 2 , Ring A 2 , the linkage of the linker and the substituent have a previously specified meaning or a previously specified preferred meaning.

[0083] A further subject matter of the invention is the organic electroluminescent device as described above, wherein the host material 1 corresponds to one of the formulas (1h), (1i) or (1j) with substituents as described above or preferably described.

[0084] In compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f), (1g), (1h), (1i) and (1j) or preferably described compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f), (1g), (1h), (1i) and (1j), n is preferably 0, 1 or 2, particularly preferably 0 or 1, very particularly preferably 0.

[0085] If n is 1, 2, or 3, then the substituent R* is, independently at each occurrence, D or an aryl group having 6 to 12 carbon atoms which may be substituted by one or more radicals R, where R has a meaning previously mentioned or preferred below. If n is 3, R* is preferably D at each occurrence.

[0086] If o is 1 or 2, then the substituent R* is preferably an aryl group having 6 to 12 C atoms, which may be substituted by one or more radicals R, particularly preferably an aryl group having 6 to 12 C atoms, most preferably unsubstituted phenyl.

[0087] In the host material 1 of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f), (1g), (1h), (1i) and (1j) or preferably described compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f), (1g), (1h), (1i) and (1j), the substituent Rx, the substituent Ry or the substituent Rz each independently represents an aromatic ring system having 6 to 18 ring atoms or a heteroaromatic ring system having 9 to 14 ring atoms, which may each be substituted by one or more radicals R, where R has a meaning given above or has a meaning given below as a preferred meaning.

[0088] In compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f), (1g), (1h), (1i) and (1j) or preferably described compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f), (1g), (1h), (1i) and (1j), Rx and Rz are each independently of one another when occurring preferably phenyl, naphthyl, 1,2-biphenyl, 1,3-biphenyl, 1,4-biphenyl, dimethylfluorenyl, dibenzofuranyl, dibenzothienyl or carbazol-N-yl, which may be substituted by one or more radicals R and wherein the attachment of the Dibenzofuranyl, dimethylfluorenyl, or dibenzothienyl is not restricted. Rx and Rz are preferably unsubstituted.

[0089] In compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f), (1g), (1h), (1i) and (1j) or preferably described compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f), (1g), (1h), (1i) and (1j), Rx and Rz are each independently of one another when they occur, particularly preferably phenyl, naphthyl, 1,4-biphenyl, dimethylfluorenyl, dibenzofuranyl or carbazol-N-yl, which may be substituted by one or more radicals R and where the attachment of the dibenzofuranyl or dimethylfluorenyl is not restricted.

[0090] In compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f), (1g), (1h), (1i) and (1j) or preferably described compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f), (1g), (1h), (1i) and (1j), Rx and Rz are each independently of one another when they occur very particularly preferably phenyl or dibenzofuranyl, preferably phenyl.

[0091] In compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f), (1g), (1h), (1i) and (1j) or preferably described compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f), (1g), (1h), (1i) and (1j), Ry, when occurring, is preferably phenyl, 1,2-biphenyl, 1,3-biphenyl, 1,4-biphenyl, dimethylfluorenyl, dibenzofuranyl or dibenzothienyl, which may be substituted by one or more radicals R. Ry is preferably unsubstituted.

[0092] In compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f), (1g), (1h), (1i) and (1j) or preferably described compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f), (1g), (1h), (1i) and (1j), Ry, when occurring, is particularly preferably phenyl, 1,4-biphenyl, dimethylfluorenyl, dibenzofuranyl or dibenzothienyl, which may be substituted by one or more radicals R.

[0093] In compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f), (1g), (1h), (1i) and (1j) or preferably described compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f), (1g), (1h), (1i) and (1j), Ry, when occurring, is very particularly preferably phenyl or dibenzofuranyl, preferably phenyl.

[0094] The substituent R in compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f), (1g), (1h), (1i) and (1j) or preferably described compounds of the formulas (1), (1a), (1a1), (1a2), (1a3), (1b), (1c), (1c1), (1c2), (1d), (1e), (1f), (1g), (1h), (1i) and (1j) is in each case independently selected at each occurrence from D, F, CN, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where one or more non-adjacent CH 2 groups are represented by R 2< C=CR 2<, O or S and where one or more H atoms can be replaced by D, F, or CN or an aryl group with 6 to 14 C atoms.The substituent R, when occurring independently of one another, is preferably selected from D, F, CN, a straight-chain alkyl group having 1 to 10 C atoms or a branched, cyclic alkyl group having 3 to 10 C atoms, or an aryl group having 6 to 14 C atoms, where one or more H atoms of the alkyl group may be replaced by D, F, or CN. The substituent R, when occurring independently of one another, is particularly preferably selected from D or phenyl.

[0095] The substituent R 2< is selected, identically or differently at each occurrence, from the group consisting of H, D, F, CN, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where one or more non-adjacent CH 2 groups may be replaced by O or S and where one or more H atoms may be replaced by D, F, or CN and is preferably H or D.

[0096] Examples of suitable host materials of formula (1), as described above or preferably described, which are selected according to the invention and are preferably used in combination with at least one compound of formula (2) in the electroluminescent device according to the invention, are the structures listed below in Table 1.

[0097] Particularly suitable compounds of formula (1), which are preferably used in combination with at least one compound of formula (2) in the electroluminescent device according to the invention, are the compounds E1 toE18:

[0098] The preparation of the compounds of formula (1) or the preferred compounds of Table 1 as well as the compounds E1 until E18 is known to the person skilled in the art. The compounds can be prepared by synthetic steps known to the person skilled in the art, such as halogenation, preferably bromination, followed by a subsequent organometallic coupling reaction, e.g., Suzuki coupling, Heck coupling, or Hartwig-Buchwald coupling.

[0099] The preparation of compounds of formula (1) can be carried out, for example, according to the following Scheme 1, where the symbols and indices have one of the meanings given above.

[0100] The preparation conditions are well known to those skilled in the art or are described in the explanatory section. The conditions described in the explanatory section also generally apply to the synthesis of host material 1 according to Scheme 1.

[0101] The preparation of compounds of formula (1) can alternatively be carried out according to the following Scheme 2, where the symbols and indices have one of the previously mentioned meanings. B(OR) 3 can be B(OCH 3 ) 3 or B(OC 2 H 5 ) 3.

[0102] The preparation conditions are well known to those skilled in the art or are described in the explanatory section. The conditions described in the explanatory section also generally apply to the synthesis of host material 1 according to Scheme 2.

[0103] The preparation of compounds of formula (1) can alternatively be carried out according to the following Scheme 3, where the symbols and indices have one of the meanings given above.

[0104] The conditions of production are well known to the person skilled in the art.

[0105] The following describes the host material 2 and its preferred embodiments, which are contained in the device according to the invention. The preferred embodiments of the host material 1 of formula (1) also apply to the mixture and / or formulation according to the invention.

[0106] Host material 2 is at least one compound of formula (2), where the symbols and indices used are: K, M are each independently of one another an unsubstituted or partially or fully deuterated or simply substituted by R 1< aromatic ring system having 6 to 40 ring atoms, when x and y are 0 and when x 1 and y 1 are 0, or K, M each independently of one another together with X or X 1< form a heteroaromatic ring system having 14 to 40 ring atoms as soon as the value of x, x1, y and / or y1 is 1; x, x1 are each independently on each occurrence 0 or 1; y, y1 are each independently on each occurrence 0 or 1; X and X 1< are each independently on each occurrence a bond or C(R +< ) 2 ; R 0< is, at each occurrence, independently of one another, an unsubstituted or partially or fully deuterated aromatic ring system having 6 to 18 ring atoms or two substituents R 0< can form a ring of the formula (1D); R 1< is an aryl group having 6 to 18 C atoms;R +< is at each occurrence independently a straight-chain or branched alkyl group having 1 to 4 C atoms and c, d, e and f are independently 0, 1 or 2. ;

[0107] In one embodiment of the invention, compounds of formula (2) are selected for the device according to the invention, as described above, which are used with compounds of formula (1), as described above or preferably described, or with the compounds of Table 1 or the compounds E1 to E18, in the light-emitting layer.

[0108] In a preferred embodiment of the device according to the invention, compounds of formula (2) are used as host material 2, in which x, y, x1 and y1 are 0. Compounds of formula (2) in which x, x1, y and y1 are 0 at each occurrence can be represented by the following formula (2a), where R 0< , c, d, e and f have a meaning given above or below and

[0109] K and M each independently represent an unsubstituted or partially or fully deuterated or simply substituted by R 1< aromatic ring system having 6 to 40 ring atoms.

[0110] The radical R 1< is, when it occurs, an aryl group having 6 to 18 C atoms, preferably phenyl, naphthyl or triphenylenyl, particularly preferably phenyl.

[0111] In preferred compounds of formula (2a), the sum of the indices c+d+e+f is preferably 0, 1 or 2 and R 0< has a meaning preferably given above or below.

[0112] In compounds of formula (2) or (2a), R 0< is, at each occurrence, independently of one another, preferably an unsubstituted aromatic ring system having 6 to 18 ring atoms, or two substituents R 0< form a ring of formula (1D). R 0< is, at each occurrence, independently of one another, particularly preferably phenyl, 1,3-biphenyl, 1,4-biphenyl, naphthyl, or triphenylenyl. R 0< is, at each occurrence, independently of one another, particularly preferably phenyl.

[0113] In compounds of formula (2) or (2a), the indices c, d, e and f are particularly preferably 0.

[0114] In compounds of formula (2) or (2a), K and M, independently of one another, are particularly preferably an unsubstituted or partially deuterated aromatic ring system having 6 to 40 ring atoms, as described above. K and M in compounds of formula (2) or (2a), independently of one another, are very particularly preferably phenyl, deuterated phenyl, 1,3-biphenyl, 1,4-biphenyl, terphenyl, partially deuterated terphenyl, quaterphenyl, naphthyl, 9,9-dimethylfluorenyl, 9,9-diphenylfluorenyl, bispirofluorenyl, or triphenylenyl.

[0115] A further subject matter of the invention is accordingly an organic electroluminescent device as described above or preferably described, wherein the at least one compound of formula (2) corresponds to a compound of formula (2a) or a preferred embodiment of the compound of formula (2a).

[0116] In a preferred embodiment of the device according to the invention, compounds of formula (2) are used as host material 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. Compounds of 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 can be represented by the following formula (2b), where X, x, y, R 0< , c, d, e and f have a meaning mentioned above or below, M is an unsubstituted or partially or fully deuterated or simply substituted by R 1< 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 as soon as the value of x or y is 1 or both values ​​of x and y are 1.

[0117] In preferred compounds of formula (2b), the sum of the indices c+d+e+f is preferably 0, 1 or 2 and R 0< has a meaning given previously or preferably given.

[0118] In compounds of formula (2) or (2b), the indices c, d, e and f are particularly preferably, independently of one another, 0 or 1. In compounds of formula (2) or (2b), the indices c, d, e and f are very particularly preferably 0. In compounds of formula (2) or (2b), the indices c, d, e and f are very particularly preferably 1. In compounds of formula (2) or (2b), the indices c, d, e and f are very particularly preferably 2.

[0119] In compounds of formula (2) or (2b), K preferably forms a heteroaromatic ring system when the sum of x+y is 1 or 2. In compounds of formula (2) or (2b), X is preferably a direct bond or C(CH 3 ) 2 .

[0120] Preferred compounds of formula (2) or (2b) can be represented by formulas (2b-1) to (2b-6), where M, R 0< , c, d, e and f have a meaning mentioned above or preferred.

[0121] In compounds of the formulas (2), (2b), (2b-1), (2b-2), (2b-3), (2b-4, (2b-5) or (2b-6), M is preferably an unsubstituted or partially deuterated aromatic ring system having 6 to 40 ring atoms, as previously described. M in compounds of the formulas (2), (2b), (2b-1), (2b-2), (2b-3), (2b-4, (2b-5) or (2b-6) is particularly preferably phenyl, deuterated phenyl, 1,3-biphenyl, 1,4-biphenyl, terphenyl, partially deuterated terphenyl, quaterphenyl, naphthyl, fluorenyl, 9,9-diphenylfluorenyl, bispirofluorenyl or triphenylenyl.

[0122] In compounds of formulas (2b-1), (2b-2), (2b-3), (2b-4), (2b-5) or (2b-6), c, d, e and f are each independently preferably 0 or 1.

[0123] A further subject matter of the invention is accordingly an organic electroluminescent device as described above or preferably described, wherein the at least one compound of formula (2) corresponds to a compound of formula (2b), (2b), (2b-1), (2b-2), (2b-3), (2b-4, (2b-5) or (2b-6) or a preferred embodiment of these compounds.

[0124] In a preferred embodiment of the device according to the invention, compounds of formula (2) are used as host material 2, in which c and f independently of one another are 0 or 1, d and e are 0, and x, x1, y, and y1 independently of one another are 0 or 1 at each occurrence, but the sum of x and y is at least 1 and the sum of x1 and y1 is at least 1. Such compounds of formula (2), as described above, can preferably be represented by the following formula (2c), where X and X 1< have a meaning given above or below, K and M each independently of one another 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.

[0125] In preferred compounds of 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 formula (2c), the sum of x and y is 1 and the sum of x1 and y1 is each 1.

[0126] Accordingly, in compounds of formula (2) or (2c), K and M preferably form a heteroaromatic ring system. X and X 1< in compounds of formula (2) or (2c) are preferably a direct bond or C(CH 3 ) 2 .

[0127] Preferred compounds of formula (2) or (2c) can be represented by formulas (2c-1) to (2c-8),

[0128] Preferred compounds of formula (2c) are also compounds H12, H13, H14, H15, H19 and H24, as described below.

[0129] A further subject matter of the invention is accordingly an organic electroluminescent device as described above or preferably described, wherein the at least one compound of formula (2) corresponds to a compound of formulas (2c), (2c-1), (2c-2), (2c-3), (2c-4, (2c-5), (2c-6), (2c-7) or (2c-8).

[0130] In a preferred embodiment of the compounds of formulas (2), (2a), (2b), (2b-1), (2b-2), (2b-3), (2b-4, (2b-5) or (2b-6), the carbazole and the bridged carbazole are each linked to one another in the 3-position.

[0131] In a preferred embodiment of the compounds of formula (2c), the two bridged carbazoles are each linked to each other in the 3-position.

[0132] Examples of suitable host materials of formulas (2), (2a), (2b), (2b-1), (2b-2), (2b-3), (2b-4), (2b-5) and (2c), which are selected according to the invention and are preferably used in combination with at least one compound of formula (1) in the electroluminescent device according to the invention, are the structures listed below in Table 2.

[0133] Particularly suitable compounds of formula (2), which are preferably used in combination with at least one compound of formula (1) in the electroluminescent device according to the invention, are the compounds H1 until H27: H1 H2 H3 H4 H5 H6 H7 H8 H9 H10 H11 H12 H13 H14 H15 H16 H17 H18 H19 H20 H21 H22 H23 H24 H25 H26 H27.

[0134] The preparation of the compounds of formula (2) or the preferred compounds of formulas (2), (2a), (2b), (2b-1), (2b-2), (2b-3), (2b-4, (2b-5) and (2c), as well as the compounds of Table 2 and H1 until H27 is known to the person skilled in the art. The compounds can be prepared by synthetic steps known to the person skilled in the art, such as halogenation, preferably bromination, followed by a subsequent organometallic coupling reaction, e.g., Suzuki coupling, Heck coupling, or Hartwig-Buchwald coupling. Some of the compounds of formula (2) are commercially available.

[0135] The above-mentioned host materials of formula (1) as well as their preferred embodiments or the compounds of Table 1 and the compounds E1 until E18can be reacted in the device according to the invention with any of the host materials mentioned of the formulas (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) as well as their preferred embodiments or the compounds of Table 2 or the compounds H1 until H27 be combined.

[0136] The aforementioned specific combinations of host materials of formula (1) with host materials of formula (2) are preferred, as described above. Preferred combinations of host materials are also described below.

[0137] The invention further relates to mixtures containing at least one compound of formula (1) and at least one compound of formula (2), where the symbols and indices used are: Ring A 1 in formula (1) corresponds to formula (1A) V 2 is O or S; Ring A 2 in formula (1) corresponds to one of the formulas (1B), (1C), (1D), (1E), (1F), (1G) or (1H), which have one or more residues R may be substituted; V 3 is O or S, Rx, Ry and Rz are each independently an aromatic ring system having 6 to 14 ring atoms or a heteroaromatic ring system having 9 to 14 ring atoms, each of which may be substituted by one or more radicals R; n is 0, 1, 2 or 3; m is 0, 1, 2, 3 or 4; o is 0, 1 or 2; p1, p2 are 0 or 1 and the sum of p1 + p2 is 1; R# is, at each occurrence, independently D, an aryl group having 6 to 12 C atoms which may be substituted by one or more R radicals, dibenzofuranyl, dibenzothienyl, or carbazolyl bonded via a C atom which may be substituted by one or more R radicals and wherein the N atom of the carbazolyl group is substituted by an aryl group having 6 to 12 C atoms which may be substituted by one or more R radicals; R* is, at each occurrence, independently D or an aryl group having 6 to 12 C atoms which may be substituted by one or more R radicals;R is selected, identically or differently at each occurrence, from D, F, CN, a straight-chain alkyl group having 1 to 20 C atoms, a branched or cyclic alkyl group having 3 to 20 C atoms, where one or more non-adjacent CH 2 groups may be replaced by R 2< C=CR 2< , O or S and where one or more H atoms may be replaced by D, F or CN or an aryl group having 6 to 14 C atoms; R 2< is selected, identically or differently at each occurrence, from the group consisting of H, D, F, CN, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where one or more non-adjacent CH 2 groups may be replaced by O or S and where one or more H atoms may be replaced by D, F, or CN;K, M are each independently of one another an unsubstituted or partially or fully deuterated or simply substituted by R 1< aromatic ring system having 6 to 40 ring atoms, when x and y are 0 and when x 1 and y 1 are 0, or K, M each independently of one another together with X or X 1< form a heteroaromatic ring system having 14 to 40 ring atoms as soon as the value of x, x1, y and / or y1 is 1; x, x1 are each independently on each occurrence 0 or 1; y, y1 are each independently on each occurrence 0 or 1; X and X 1< are each independently on each occurrence a bond or C(R +< ) 2 ; R 0< is, at each occurrence, independently of one another, an unsubstituted or partially or fully deuterated aromatic ring system having 6 to 18 ring atoms or two substituents R 0< can form a ring of the formula (1D); R 1< is an aryl group having 6 to 18 C atoms;R +< is at each occurrence independently a straight-chain or branched alkyl group having 1 to 4 C atoms and c, d, e and f are independently 0, 1 or 2. ;

[0138] The statements regarding the host materials of formulas (1) and (2) as well as their preferred embodiments and their combination also apply accordingly to the mixture according to the invention.

[0139] Particularly preferred mixtures of the host materials of formula (1) with the host materials of formula (2) for the device according to the invention are obtained by combining the compounds E1 until E18 with the compounds in Table 2.

[0140] Very particularly preferred mixtures of the host materials of formula (1) with the host materials of formula (2) for the device according to the invention are obtained by combining the compounds E1 until E18 with the connections H1 until H27as shown in Table 3 below. 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 E1 H2 M20 E2 H2 M21 E3 H2 M22 E4 H2 M23 E5 H2 M24 E6 H2 M25 E7 H2 M26 E8 H2 M27 E9 H2 M28 E10 H2 M29 E11 H2 M30 E12 H2 M31 E13 H2 M32 E14 H2 M33 E15 H2 M34 E16 H2 M35 E17 H2 M36 E18 H2 M37 E1 H3 M38 E2 H3 M39 E3 H3 M40 E4 H3 M41 E5 H3 M42 E6 H3 M43 E7 H3 M44 E8 H3 M45 E9 H3 M46 E10 H3 M47 E11 H3 M48 E12 H3 M49 E13 H3 M50 E14 H3 M51 E15 H3 M52 E16 H3 M53 E17 H3 M54 E18 H3 M55 E1 H4 M56 E2 H4 M57 E3 H4 M58 E4 H4 M59 E5 H4 M60 E6 H4 M61 E7 H4 M62 E8 H4 M63 E9 H4 M64 E10 H4 M65 E11 H4 M66 E12 H4 M67 E13 H4 M68 E14 H4 M69 E15 H4 M70 E16 H4 M71 E17 H4 M72 E18 H4 M73 E1 H5 M74 E2 H5 M75 E3 H5 M76 E4 H5 M77 E5 H5 M78 E6 H5 M79 E7 H5 M80 E8 H5 M81 E9 H5 M82 E10 H5 M83 E11 H5 M84 E12 H5 M85 E13 H5 M86 E14 H5 M87 E15 H5 M88 E16 H5 M89 E17 H5 M90 E18 H5 M91 E1 H6 M92 E2 H6 M93 E3 H6 M94 E4 H6 M95 E5 H6 M96 E6 H6 M97 E7 H6 M98 E8 H6 M99 E9 H6 M100 E10 H6 M101 E11 H6 M102 E12 H6 M103 E13 H6 M104 E14 H6 M105 E15 H6 M106 E16 H6 M107 E17 H6 M108 E18 H6 M109 E1 H7 M110 E2 H7 M111 E3 H7 M112 E4 H7 M113 E5 H7 M114 E6 H7 M115 E7 H7 M116 E8 H7 M117 E9 H7 M118 E10 H7 M119 E11 H7 M120 E12 H7 M121 E13 H7 M122 E14 H7 M123 E15 H7 M124 E16 H7 M125 E17 H7 M126 E18 H7 M127 E1 H8 M128 E2 H8 M129 E3 H8 M130 E4 H8 M131 E5 H8 M132 E6 H8 M133 E7 H8 M134 E8 H8 M135 E9 H8 M136 E10 H8 M137 E11 H8 M138 E12 H8 M139 E13 H8 M140 E14 H8 M141 E15 H8 M142 E16 H8 M143 E17 H8 M144 E18 H8 M145 E1 H9 M146 E2 H9 M147 E3 H9 M148 E4 H9 M149 E5 H9 M150 E6 H9 M151 E7 H9 M152 E8 H9 M153 E9 H9 M154 E10 H9 M155 E11 H9 M156 E12 H9 M157 E13 H9 M158 E14 H9 M159 E15 H9 M160 E16 H9 M161 E17 H9 M162 E18 H9 M163 E1 H10 M164 E2 H10 M165 E3 H10 M166 E4 H10 M167 E5 H10 M168 E6 H10 M169 E7 H10 M170 E8 H10 M171 E9 H10 M172 E10 H10 M173 E11 H10 M174 E12 H10 M175 E13 H10 M176 E14 H10 M177 E15 H10 M178 E16 H10 M179 E17 H10 M180 E18 H10 M181 E1 H11 M182 E2 H11 M183 E3 H11 M184 E4 H11 M185 E5 H11 M186 E6 H11 M187 E7 H11 M188 E8 H11 M189 E9 H11 M190 E10 H11 M191 E11 H11 M192 E12 H11 M193 E13 H11 M194 E14 H11 M195 E15 H11 M196 E16 H11 M197 E17 H11 M198 E18 H11 M199 E1 H12 M200 E2 H12 M201 E3 H12 M202 E4 H12 M203 E5 H12 M204 E6 H12 M205 E7 H12 M206 E8 H12 M207 E9 H12 M208 E10 H12 M209 E11 H12 M210 E12 H12 M211 E13 H12 M212 E14 H12 M213 E15 H12 M214 E16 H12 M215 E17 H12 M216 E18 H12 M217 E1 H13 M218 E2 H13 M219 E3 H13 M220 E4 H13 M221 E5 H13 M222 E6 H13 M223 E7 H13 M224 E8 H13 M225 E9 H13 M226 E10 H13 M227 E11 H13 M228 E12 H13 M229 E13 H13 M230 E14 H13 M231 E15 H13 M232 E16 H13 M233 E17 H13 M234 E18 H13 M235 E1 H14 M236 E2 H14 M237 E3 H14 M238 E4 H14 M239 E5 H14 M240 E6 H14 M241 E7 H14 M242 E8 H14 M243 E9 H14 M244 E10 H14 M245 E11 H14 M246 E12 H14 M247 E13 H14 M248 E14 H14 M249 E15 H14 M250 E16 H14 M251 E17 H14 M252 E18 H14 M253 E1 H15 M254 E2 H15 M255 E3 H15 M256 E4 H15 M257 E5 H15 M258 E6 H15 M259 E7 H15 M260 E8 H15 M261 E9 H15 M262 E10 H15 M263 E11 H15 M264 E12 H15 M265 E13 H15 M266 E14 H15 M267 E15 H15 M268 E16 H15 M269 E17 H15 M270 E18 H15 M271 E1 H16 M272 E2 H16 M273 E3 H16 M274 E4 H16 M275 E5 H16 M276 E6 H16 M277 E7 H16 M278 E8 H16 M279 E9 H16 M280 E10 H16 M281 E11 H16 M282 E12 H16 M283 E13 H16 M284 E14 H16 M285 E15 H16 M286 E16 H16 M287 E17 H16 M288 E18 H16 M289 E1 H17 M290 E2 H17 M291 E3 H17 M292 E4 H17 M293 E5 H17 M294 E6 H17 M295 E7 H17 M296 E8 H17 M297 E9 H17 M298 E10 H17 M299 E11 H17 M300 E12 H17 M301 E13 H17 M302 E14 H17 M303 E15 H17 M304 E16 H17 M305 E17 H17 M306 E18 H17 M307 E1 H18 M308 E2 H18 M309 E3 H18 M310 E4 H18 M311 E5 H18 M312 E6 H18 M313 E7 H18 M314 E8 H18 M315 E9 H18 M316 E10 H18 M317 E11 H18 M318 E12 H18 M319 E13 H18 M320 E14 H18 M321 E15 H18 M322 E16 H18 M323 E17 H18 M324 E18 H18 M325 E1 H19 M326 E2 H19 M327 E3 H19 M328 E4 H19 M329 E5 H19 M330 E6 H19 M331 E7 H19 M332 E8 H19 M333 E9 H19 M334 E10 H19 M335 E11 H19 M336 E12 H19 M337 E13 H19 M338 E14 H19 M339 E15 H19 M340 E16 H19 M341 E17 H19 M342 E18 H19 M343 E1 H20 M344 E2 H20 M345 E3 H20 M346 E4 H20 M347 E5 H20 M348 E6 H20 M349 E7 H20 M350 E8 H20 M351 E9 H20 M352 E10 H20 M353 E11 H20 M354 E12 H20 M355 E13 H20 M356 E14 H20 M357 E15 H20 M358 E16 H20 M359 E17 H20 M360 E18 H20 M361 E1 H21 M362 E2 H21 M363 E3 H21 M364 E4 H21 M365 E5 H21 M366 E6 H21 M367 E7 H21 M368 E8 H21 M369 E9 H21 M370 E10 H21 M371 E11 H21 M372 E12 H21 M373 E13 H21 M374 E14 H21 M375 E15 H21 M376 E16 H21 M377 E17 H21 M378 E18 H21 M379 E1 H22 M380 E2 H22 M381 E3 H22 M382 E4 H22 M383 E5 H22 M384 E6 H22 M385 E7 H22 M386 E8 H22 M387 E9 H22 M388 E10 H22 M389 E11 H22 M390 E12 H22 M391 E13 H22 M392 E14 H22 M393 E15 H22 M394 E16 H22 M395 E17 H22 M396 E18 H22 M397 E1 H23 M398 E2 H23 M399 E3 H23 M400 E4 H23 M401 E5 H23 M402 E6 H23 M403 E7 H23 M404 E8 H23 M405 E9 H23 M406 E10 H23 M407 E11 H23 M408 E12 H23 M409 E13 H23 M410 E14 H23 M411 E15 H23 M412 E16 H23 M413 E17 H23 M414 E18 H23 M415 E1 H24 M416 E2 H24 M417 E3 H24 M418 E4 H24 M419 E5 H24 M420 E6 H24 M421 E7 H24 M422 E8 H24 M423 E9 H24 M424 E10 H24 M425 E11 H24 M426 E12 H24 M427 E13 H24 M428 E14 H24 M429 E15 H24 M430 E16 H24 M431 E17 H24 M432 E18 H24 M433 E1 H25 M434 E2 H25 M435 E3 H25 M436 E4 H25 M437 E5 H25 M438 E6 H25 M439 E7 H25 M440 E8 H25 M441 E9 H25 M442 E10 H25 M443 E11 H25 M444 E12 H25 M445 E13 H25 M446 E14 H25 M447 E15 H25 M448 E16 H25 M449 E17 H25 M450 E18 H25 M451 E1 H26 M452 E2 H26 M453 E3 H26 M454 E4 H26 M455 E5 H26 M456 E6 H26 M457 E7 H26 M458 E8 H26 M459 E9 H26 M460 E10 H26 M461 E11 H26 M462 E12 H26 M463 E13 H26 M464 E14 H26 M465 E15 H26 M466 E16 H26 M467 E17 H26 M468 E18 H26 M469 E1 H27 M470 E2 H27 M471 E3 H27 M472 E4 H27 M473 E5 H27 M474 E6 H27 M475 E7 H27 M476 E8 H27 M477 E9 H27 M478 E10 H27 M479 E11 H27 M480 E12 H27 M481 E13 H27 M482 E14 H27 M483 E15 H27 M484 E16 H27 M485 E17 H27 M486 E18 H27

[0141] The concentration of the electron-transporting host material of formula (1), as described above or preferably described, in the mixture according to the invention or in the light-emitting layer of the device according to the invention is in the range from 5 wt.% to 90 wt.%, preferably in the range from 10 wt.% to 85 wt.%, more preferably in the range from 20 wt.% to 85 wt.%, even more preferably in the range from 30 wt.% to 80 wt.%, very particularly preferably in the range from 20 wt.% to 60 wt.% and most preferably in the range from 30 wt.% to 50 wt.%, based on the total mixture or based on the total composition of the light-emitting layer.

[0142] The concentration of the hole-transporting host material of formula (2), as described above or described as preferred, in the mixture according to the invention or in the light-emitting layer of the device according to the invention is in the range from 10 wt.% to 95 wt.%, preferably in the range from 15 wt.% to 90 wt.%, more preferably in the range from 15 wt.% to 80 wt.%, even more preferably in the range from 20 wt.% to 70 wt.%, very particularly preferably in the range from 40 wt.% to 80 wt.% and most preferably in the range from 50 wt.% to 70 wt.%, based on the total mixture or based on the total composition of the light-emitting layer.

[0143] The present invention also relates to a mixture which, in addition to the above-mentioned host materials 1 and 2, as described above or preferably described, in particular mixtures M1 to M486, contains at least one phosphorescent emitter.

[0144] The present invention also relates to an organic electroluminescent device as described above or preferably described, wherein the light-emitting layer contains at least one phosphorescent emitter in addition to the above-mentioned host materials 1 and 2 as described above or preferably described, in particular the material combinations M1 to M486.

[0145] The term "phosphorescent emitters" typically encompasses compounds in which light emission occurs through a spin-forbidden transition from an excited state with higher spin multiplicity, i.e., a spin state > 1, for example, through a transition from a triplet state or a state with an even higher spin quantum number, such as a quintet state. Preferably, this refers to a transition from a triplet state.

[0146] Particularly suitable phosphorescent emitters (= triplet emitters) are compounds that, upon suitable excitation, emit light, preferably in the visible range, and also contain at least one atom with an atomic number greater than 20, preferably greater than 38 and less than 84, particularly preferably greater than 56 and less than 80, in particular a metal with this atomic number. Preferably, compounds containing copper, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, iridium, palladium, platinum, silver, gold, or europium are used as phosphorescent emitters, in particular compounds containing iridium or platinum. For the purposes of the present invention, all luminescent compounds containing the above-mentioned metals are considered phosphorescent emitters.

[0147] In general, all phosphorescent complexes as used in the prior art for phosphorescent OLEDs and as known to the person skilled in the art in the field of organic electroluminescent devices are suitable.

[0148] Preferred phosphorescent emitters according to the present invention correspond to the formulas (3a) or (3b), where the symbols and indices for these formulas (3a) and (3b) have the meaning: n+m is 3, n is 1 or 2, m is 2 or 1, R is H, D or a branched or linear alkyl group having 1 to 10 C atoms or a partially or fully deuterated branched or linear alkyl group having 1 to 10 C atoms or a cycloalkyl group having 4 to 7 C atoms, which may be partially or fully substituted with deuterium.

[0149] A further subject matter of the invention is accordingly an organic electroluminescent device as described above or preferably described, characterized in that the light-emitting layer contains, in addition to the host materials 1 and 2, at least one phosphorescent emitter which corresponds to one of the formulas (3a) or (3b), as described above.

[0150] In emitters of formulas (3a) or (3b), n is preferably 1 and m is preferably 2. In emitters of formulas (3a) or (3b), at least one R is preferably different from H. In emitters of formulas (3a) or (3b), two R are preferably different from H and have one of the meanings otherwise previously given for the emitters of formulas (3a) and (3b).

[0151] Preferred phosphorescent emitters according to the present invention correspond to the formulas (I), (II), (III), (IV) or (V), where the symbols and indices for these formulas (I), (II), (III), (IV) and (V) have the meaning: R 1 is H or D, R 2 is H, D or a branched or linear alkyl group having 1 to 10 C atoms or a partially or fully deuterated branched or linear alkyl group having 1 to 10 C atoms or a cycloalkyl group having 4 to 10 C atoms, which may be partially or fully substituted with deuterium.

[0152] Preferred phosphorescent emitters according to the present invention correspond to the formulas (VI), (VII) or (VIII), where the symbols and indices for these formulas (VI), (VII) and (VIII) have the meaning: R 1 is H or D, R 2 is H, D, F or a branched or linear alkyl group having 1 to 10 C atoms or a partially or fully deuterated branched or linear alkyl group having 1 to 10 C atoms or a cycloalkyl group having 4 to 10 C atoms, which may be partially or fully substituted with deuterium.

[0153] Preferred examples of phosphorescent emitters are described in WO2019007867 on pages 120 to 126 in Table 5 and on pages 127 to 129 in Table 6. The emitters are incorporated into the description by this reference.

[0154] Particularly preferred examples of phosphorescent emitters are listed in the following Tables 4a and 4b.

[0155] In the mixtures according to the invention or in the light-emitting layer of the device according to the invention, each mixture selected from the sum of the mixtures M1 to M486 is preferably combined with a compound of the formulas (3a) or (3b) or a compound of the formulas (I) to (VIII) or a compound from Table 4a or 4b.

[0156] The light-emitting layer in the organic electroluminescent device according to the invention containing at least one phosphorescent emitter is preferably an infrared-emitting, yellow, orange, red, green, blue or ultraviolet-emitting layer, particularly preferably a yellow or red-emitting layer and very particularly preferably a red-emitting layer.

[0157] A yellow-emitting layer is understood to be a layer whose photoluminescence maximum lies in the range from 540 to 570 nm. An orange-emitting layer is understood to be a layer whose photoluminescence maximum lies in the range from 570 to 600 nm. A red-emitting layer is understood to be a layer whose photoluminescence maximum lies in the range from 600 to 750 nm. A green-emitting layer is understood to be a layer whose photoluminescence maximum lies in the range from 490 to 540 nm. A blue-emitting layer is understood to be a layer whose photoluminescence maximum lies in the range from 440 to 490 nm. The photoluminescence maximum of the layer is determined by measuring the photoluminescence spectrum of the layer with a layer thickness of 50 nm at room temperature, wherein the layer contains the inventive combination of the host materials of formulas (1) and (2) and the corresponding emitter.

[0158] The photoluminescence spectrum of the layer is recorded, for example, using a commercially available photoluminescence spectrometer.

[0159] The photoluminescence spectrum of the selected emitter is usually measured in an oxygen-free solution (10-5 molar). The measurement is performed at room temperature, and any solvent in which the selected emitter dissolves at the specified concentration is suitable. Particularly suitable solvents are usually toluene or 2-methyl-THF, but also dichloromethane. The measurement is performed using a commercially available 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 according to: E(T1 in eV) = 1240 / E(T1 in nm) = 1240 / PLmax. (in nm).

[0160] Preferred phosphorescent emitters are therefore red emitters, preferably of formulas (3a) or (3b), of formulas (I) to (VIII) or from Table 4a or 4b, whose triplet energy T 1 is preferably between ~2.1 eV and ~1.9 eV.

[0161] Preferred phosphorescent emitters are therefore yellow emitters, preferably of formulas (3a) or (3b), of formulas (I) to (VIII) or from Table 4a or 4b, whose triplet energy T 1 is preferably between ~2.3 eV and ~2.1 eV.

[0162] Preferred phosphorescent emitters are therefore green emitters, preferably of formulas (3a) or (3b), of formulas (I) to (VIII) or from Table 4a or 4b, whose triplet energy T 1 is preferably between ~2.5 eV and ~2.3 eV.

[0163] Particularly preferred phosphorescent emitters are accordingly yellow or red emitters, preferably of the formulas (3a) or (3b), of the formulas (I) to (VIII) or from Table 4a or 4b, as previously described.

[0164] Accordingly, very particularly preferred phosphorescent emitters are red emitters, preferably of the formulas (3a) or (3b), of the formulas (I) to (VIII) or from Table 4a or 4b, whose triplet energy T 1 is preferably ≤ 2.3 eV.

[0165] Red emitters, preferably of the formulas (3a) or (3b), of the formulas (I) to (VIII) or from Table 4a or 4b, as described above, are very particularly preferably selected for the composition according to the invention or the emitting layer according to the invention.

[0166] The light-emitting layer of the device according to the invention may also contain fluorescent emitters.

[0167] Preferred fluorescent emitters are selected from the class of arylamines. An arylamine or aromatic amine within the meaning of this invention is understood to be a compound containing three substituted or unsubstituted aromatic or heteroaromatic ring systems directly bonded to the nitrogen.

[0168] In a further preferred embodiment of the invention, the at least one light-emitting layer of the organic electroluminescent device can comprise, in addition to the host materials 1 and 2, as described above or described as preferred, further host materials or matrix materials, so-called mixed-matrix systems. The mixed-matrix systems preferably comprise three or four different matrix materials, particularly preferably three different matrix materials (i.e., a 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 a matrix component of a mixed-matrix system, are selected from wide-band gap materials, bipolar host materials, electron transport materials (ETM) and hole transport materials (HTM).

[0169] Under wide-band-gap-Material is understood herein to mean a material within the meaning of the disclosure of US 7,294,849, which is characterized by a band gap of at least 3.5 eV, where band gap is understood to be the distance between HOMO and LUMO energy of a material.

[0170] More detailed information on mixed-matrix systems can be found, inter alia, in the application WO 2010 / 108579. Particularly suitable matrix materials, which can be used in combination with host materials 1 and 2, as described above or preferably described, as matrix components of a mixed-matrix system in phosphorescent or fluorescent organic electroluminescent devices, are selected from the preferred matrix materials for phosphorescent emitters listed below or the preferred matrix materials for fluorescent emitters, depending on the type of emitter used. The mixed-matrix system is preferably optimized for an emitter of formulas (3a) or (3b), of formulas (I) to (VIII), or from Table 4a or 4b.

[0171] In addition to host materials 1 and 2, various classes of substances are suitable as further host materials, preferably for fluorescent emitters, in the device according to the invention, as described above, particularly preferably comprising the combination of host materials selected from M1 to M486. Preferred further host materials are selected from the classes of oligoarylenes, oligoarylenevinylenes, polypodal metal complexes, ketones, phosphine oxides, sulfoxides, boronic acid derivatives, and benzanthracenes. An oligoarylene within the meaning of this invention is understood to mean a compound in which at least three aryl or arylene groups are bonded to one another.

[0172] As further matrix materials, preferably for phosphorescent emitters, in addition to the host materials 1 and 2 in the device according to the invention, as described above, particularly preferably comprising the combination of the host materials selected from M1 to M486, as described above, the following classes of compounds are suitable: aromatic amines, in particular triarylamines, carbazole derivatives, bridged carbazole derivatives, indenocarbazole derivatives, azacarbazole derivatives, indolocarbazole derivatives, ketones, phosphine oxides, sulfoxides, sulfones, oligophenylenes, bipolar matrix materials, silanes, azaboroles or boronic esters, triazine derivatives, zinc complexes, aluminum complexes, diazasilole and tetraazasilole derivatives, diazaphosphole derivatives and aluminum complexes.

[0173] According to one embodiment of the present invention, the mixture contains no further components, i.e., functional materials, besides the electron-transporting host material of formula (1) and the hole-transporting host material of formula (2). These are material mixtures used as such to produce the light-emitting layer. These mixtures are also referred to as premix systems, which are used as the sole material source during the vapor deposition of the host materials for the light-emitting layer and which have a constant mixing ratio during vapor deposition. This allows for the simple and rapid deposition of a layer with a uniform distribution of the components, without the need for precise control of a large number of material sources.

[0174] According to an alternative embodiment of the present invention, the mixture contains, in addition to the components electron-transporting host material of formula (1) and hole-transporting host material of formula (2), the phosphorescent emitter as described above. With a suitable mixing ratio during vapor deposition, this mixture can also be used as the sole material source, as described above.

[0175] According to an alternative embodiment of the present invention, the mixture contains, in addition to the components electron-transporting host material of formula (1) and hole-transporting host material of formula (2), another matrix material and / or the phosphorescent emitter, as described above. With a suitable mixing ratio during vapor deposition, this mixture can also be used as the sole material source, as described above.

[0176] The components or constituents of the light-emitting layer of the device according to the invention can thus be processed by vapor deposition or from solution. The material combination of host materials 1 and 2, as described above or preferably described, optionally with the phosphorescent emitter and / or another matrix material, as described above or preferably described, are provided for this purpose in a formulation containing at least one solvent. These formulations can be, for example, solutions, dispersions, or emulsions. It may be preferred to use mixtures of two or more solvents for this purpose.

[0177] A further subject of the present invention is therefore a formulation comprising a mixture according to the invention of host materials 1 and 2, as described above, optionally in combination with a phosphorescent emitter, as described above or preferably described, and at least one solvent.

[0178] Suitable and preferred solvents are, for example, toluene, anisole, o-, m- or p-xylene, methyl benzoate, mesitylene, tetralin, veratrole, THF, methyl-THF, THP, chlorobenzene, dioxane, phenoxytoluene, in particular 3-phenoxytoluene, (-)-fenchone, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, 1-methylnaphthalene, 2-methylbenzothiazole, 2-phenoxyethanol, 2-pyrrolidinone, 3-methylanisole, 4-methylanisole, 3,4-dimethylanisole, 3,5-dimethylanisole, acetophenone, α-terpineol, benzothiazole, butylbenzoate, cumene, cyclohexanol, cyclohexanone, cyclohexylbenzene, Decalin, dodecyl benzene, ethyl benzoate, indane, methyl benzoate, NMP, p-cymene, phenetol, 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.

[0179] The formulation may also contain at least one further organic or inorganic compound that is also used in the light-emitting layer of the device according to the invention, in particular a further emitting compound and / or a further matrix material. Suitable emitting compounds and further matrix materials have already been listed above.

[0180] The light-emitting layer in the device according to the invention according to the preferred embodiments and the emitting compound preferably contains between 99.9 and 1 vol.%, more preferably between 99 and 10 vol.%, particularly preferably between 98 and 60 vol.%, very particularly preferably between 97 and 80 vol.% of matrix material composed of at least one compound of formula (1) and at least one compound of formula (2) according to the preferred embodiments, based on the total composition of emitter and matrix material. Accordingly, the light-emitting layer in the device according to the invention preferably contains between 0.1 and 99 vol.%, more preferably between 1 and 90 vol.%, particularly preferably between 2 and 40 vol.%, very particularly preferably between 3 and 20 vol.% of the emitter, based on the total composition of the light-emitting layer consisting of emitter and matrix material.If the compounds are processed from solution, the corresponding amounts in wt.% are preferably used instead of the amounts in vol.% given above.

[0181] The light-emitting layer in the device according to the invention according to the preferred embodiments and the emitting compound preferably contains the matrix material of formula (1) and the matrix material of formula (2) in a volume percentage ratio between 3:1 and 1:3, preferably between 1:2.5 and 1:1, particularly preferably between 1:2 and 1:1. If the compounds are processed from solution, the corresponding ratio in wt.% is preferably used instead of the above-specified ratio in vol.%.

[0182] The present invention also relates to an organic electroluminescent device as described above or preferably described, wherein the organic layer contains a hole-injection layer (HIL) and / or a hole-transport layer (HTL) whose hole-injecting material and hole-transporting material are monoamines that do not contain a carbazole moiety. Preferably, the hole-injecting material and hole-transporting material contain a monoamine containing a fluorenyl or bispirofluorenyl group, but no carbazole moiety.

[0183] Preferred monoamines which are used according to the invention in the organic layer of the device according to the invention can be described by the formula (4) where the symbols and indices for this formula (4) have the meaning: Ar and Ar' are each independently at each occurrence 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 is each independently at each occurrence 0 or 1; m is each independently at each occurrence 0 or 1.

[0184] Preferably, at least one Ar' in formula (4) is a group of the following formulas (4a) or (4b), where R in formula (4a) and (4b) is selected on each occurrence, identically or differently, from H, D, F, CN, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where one or more non-adjacent CH 2 groups may be replaced by R 2< C=CR 2< , O or S and where one or more H atoms may be replaced by D, F or CN and where two R may form a cyclic or polycyclic ring.

[0185] Preferred monoamines used according to the invention in the organic layer of the device according to the invention are described in Table 5.

[0186] Furthermore, in combination with the compounds of Table 5 or as alternatives to compounds of Table 5, preferred hole transport materials are materials that can be used in a hole transport, hole injection or electron blocking layer, such as indenofluorenamine derivatives, hexaazatriphenylene derivatives, amine derivatives with condensed aromatics, monobenzoindenofluorenamines, dibenzoindenofluorenamines, dihydroacridine derivatives.

[0187] The sequence of layers in the organic electroluminescent device according to the invention is preferably the following: anode / hole injection layer / hole transport layer / emitting layer / electron transport layer / electron injection layer / cathode.

[0188] This sequence of layers is a preferred sequence. It should be noted again that not all of the layers mentioned need to be present, and / or that additional layers may be present.

[0189] The organic electroluminescent device according to the invention can contain a plurality of emitting layers. At least one of the emitting layers is the light-emitting layer according to the invention comprising at least one compound of formula (1) as host material 1 and at least one compound of formula (2) as host material 2, as described above. In this case, these emitting layers particularly preferably have a total of several emission maxima between 380 nm and 750 nm, resulting in overall white emission. This means that various emitting compounds that can fluoresce or phosphoresce and that emit blue, yellow, orange, or red light are used in the emitting layers.

[0190] All materials used in the prior art as electron-transport materials in the electron-transport layer can be used as materials for the electron-transport layer. Particularly suitable are aluminum complexes, for example Alq 3 , zirconium complexes, for example Zrq 4 , 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.

[0191] Suitable cathodes for the device according to the invention include metals with low work functions, metal alloys, or multilayer structures made of different metals, such as alkaline earth metals, alkali metals, main group metals, or lanthanides (e.g., Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.). Alloys made of an alkali or alkaline earth metal and silver, for example, an alloy of magnesium and silver, are also suitable. In multilayer structures, in addition to the metals mentioned, other metals with a relatively high work function, such as Ag or Al, can also be used. Combinations of the metals, such as Ca / Ag, Mg / Ag, or Ba / Ag, are then generally used. It may also be preferable to introduce a thin intermediate layer of a material with a high dielectric constant between a metallic cathode and the organic semiconductor.Suitable materials for this purpose include alkali metal or alkaline earth metal fluorides, as well as the corresponding oxides or carbonates (e.g., LiF, Li 2 O, BaF 2 , MgO, NaF, CsF, Cs 2 CO 3 , etc.). Lithium quinolinate (LiQ) can also be used. The thickness of this layer is preferably between 0.5 and 5 nm.

[0192] Materials with a high work function are preferred as the anode. The anode preferably has a work function greater than 4.5 eV vs. vacuum. Metals with a high redox potential, such as Ag, Pt, or Au, are suitable for this purpose. Metal / metal oxide electrodes (e.g., Al / Ni / NiOx, Al / PtOx) may also be preferred. For some applications, at least one of the electrodes must be transparent or partially transparent to enable either the irradiation of the organic material (organic solar cell) or the coupling out of light (OLED, O-LASER). Preferred anode materials here are conductive mixed metal oxides. Indium tin oxide (ITO) or indium zinc oxide (IZO) are particularly preferred. Also preferred are conductive, doped organic materials, in particular conductive doped polymers.Furthermore, the anode can also consist of several layers, for example an inner layer of ITO and an outer layer of a metal oxide, preferably tungsten oxide, molybdenum oxide or vanadium oxide.

[0193] The organic electroluminescent device according to the invention is structured, contacted and finally sealed accordingly (depending on the application) during production, since the lifetime of the devices according to the invention is shortened in the presence of water and / or air.

[0194] The production of the device according to the invention is not restricted in this respect. It is possible for one or more organic layers, including the light-emitting layer, to be coated using a sublimation process. The materials are vapor-deposited in vacuum sublimation systems at an initial pressure of less than 10 -5 mbar, preferably less than 10 -6 mbar. However, it is also possible for the initial pressure to be even lower, for example, less than 10 -7 mbar.

[0195] The organic electroluminescent device according to the invention is preferably characterized in that one or more layers are coated using the OVPD (Organic Vapor Phase Deposition) process or by means of carrier gas sublimation. The materials are applied at a pressure between 10 -5 mbar and 1 bar. A special case of this process is the OVJP (Organic Vapor Jet Printing) process, in which the materials are applied directly through a nozzle and thus structured (e.g., BMS Arnold et al., Appl. Phys. Lett. 2008, 92, 053301).

[0196] Furthermore, the organic electroluminescent device according to the invention is preferably characterized in that one or more organic layers comprising the composition according to the invention are produced from solution, for example by spin coating, or by any printing process, such as screen printing, flexographic printing, nozzle printing, or offset printing, but particularly preferably LITI (Light Induced Thermal Imaging, thermal transfer printing) or inkjet printing. Soluble host materials 1 and 2 and phosphorescent emitters are required for this purpose. Processing from solution has the advantage that, for example, the light-emitting layer can be applied very easily and cost-effectively. This technique is particularly suitable for the mass production of organic electroluminescent devices.

[0197] Furthermore, hybrid processes are possible, in which, for example, one or more layers are applied from solution and one or more further layers are deposited by vapor deposition.

[0198] These methods are generally known to the person skilled in the art and can be applied to organic electroluminescent devices.

[0199] A further subject of the invention is therefore a method for producing the organic electroluminescent device according to the invention, as described above or preferably described, characterized in that the organic layer, preferably the light-emitting layer, the hole injection layer and / or hole transport layer, is applied by vapor phase deposition, in particular with a sublimation process and / or with an OVPD (Organic Vapor Phase Deposition) process and / or with the aid of carrier gas sublimation, or from solution, in particular by spin coating or with a printing process.

[0200] When manufactured by vapor deposition, there are basically two ways in which the organic layer according to the invention, preferably the light-emitting layer, can be applied or vaporized onto any substrate or the previous layer. Firstly, the materials used can each be placed in a single material source and then evaporated from the various material sources ("co-evaporation"). Secondly, the various materials can be premixed ("premixed, premix systems"), and the mixture can be placed in a single material source, from which it is then vaporized ("premix evaporation"). This allows for the vapor deposition of the light-emitting layer with a uniform distribution of the components in a simple and rapid manner, without the need for precise control of a large number of material sources.

[0201] A further subject of the invention is therefore a process for producing the device according to the invention, characterized in that the at least one compound of the formula (1), as described above or as described as preferred, and the at least one compound of the formula (2), as described above or as described as preferred, are deposited successively or simultaneously from at least two material sources, optionally with the at least one phosphorescent emitter, as described above or as described as preferred, from the gas phase and form the light-emitting layer.

[0202] In a preferred embodiment of the present invention, the light-emitting layer is applied by vapor deposition, wherein the components of the composition are premixed and evaporated from a single material source.

[0203] A further subject of the invention is therefore a process for producing the device according to the invention, characterized in that the at least one compound of formula (1) and the at least one compound of formula (2) are deposited as a mixture, successively or simultaneously with the at least one phosphorescent emitter, from the gas phase and form the light-emitting layer.

[0204] The invention further provides a process for producing the device according to the invention, as described above or preferably described, characterized in that the at least one compound of formula (1) and the at least one compound of formula (2), as described above or preferably described, together with the at least one phosphorescent emitter, are applied from solution to form the light-emitting layer.

[0205] The devices according to the invention are characterized by the following surprising advantages over the prior art: The use of the described material combination of the host materials 1 and 2, as described above, leads in particular to an increase in the service life of the devices.

[0206] As can be seen in the example given below, by comparing the data for OLEDs with combinations from the prior art, it can be determined that the inventive combinations of matrix materials in the EML lead to devices whose lifetime is significantly increased, regardless of the emitter concentration.

[0207] It should be noted that variations of the embodiments described in the present invention fall within the scope of this invention. Any feature disclosed in the present invention may, unless explicitly excluded, be replaced by alternative features serving the same, equivalent, or similar purpose. Thus, unless otherwise stated, any feature disclosed in the present invention is to be considered an example of a generic series or an equivalent or similar feature.

[0208] All features of the present invention may be combined with each other in any way, unless certain features and / or steps are mutually exclusive. This applies in particular to preferred features in combination with preferred features of the present invention. This applies in particular to preferred features in combination with particularly preferred features of the present invention. Likewise, features of non-essential combinations may be used separately (and not in combination).

[0209] The teaching of technical action disclosed in the present invention can be abstracted and combined with other examples.

[0210] The invention is explained in more detail by the following examples, without intending to limit it thereby. Examples General methods:

[0211] The Gaussian16 program package (Rev. B.01) is used for all quantum chemical calculations. The neutral singlet ground state is optimized at the B3LYP / 6-31G(d) level of theory. HOMO and LUMO values ​​are determined at the B3LYP / 6-31G(d) level for the ground-state energy optimized with B3LYP / 6-31G(d). TD-DFT singlet and triplet excitations (vertical excitations) are then calculated using the same method (B3LYP / 6-31G(d)) and the optimized ground-state geometry. The default settings for SCF and gradient convergence are used.

[0212] From the energy calculation, the HOMO is determined as the last orbital occupied by two electrons (alpha occupancy eigenvalues) and the LUMO as the first unoccupied orbital (alpha virtual eigenvalues) in Hartree units, where HEh and LEh represent the HOMO energy in Hartree units and the LUMO energy in Hartree units, respectively. From this, the HOMO and LUMO values ​​in electronvolts, calibrated using cyclic voltammetry measurements, are determined as follows: HOMOcorr = 0.90603 * HOMO − 0.84836 LUMOcorr = 0.99687 * LUMO − 0.72445

[0213] The triplet level T1 of a material is defined as the relative excitation energy (in eV) of the lowest energy triplet state resulting from quantum chemical energy calculations.

[0214] The singlet level S1 of a material is defined as the relative excitation energy (in eV) of the singlet state with the second lowest energy, which results from the quantum chemical energy calculation.

[0215] The lowest energy singlet state is called S0.

[0216] The method described here is independent of the software package used and always produces the same results. Examples of commonly used programs for this purpose are "Gaussian09" (Gaussian Inc.) and Q-Chem 4.1 (Q-Chem, Inc.). In this example, the program package "Gaussian16 (Rev. B.01)" is used to calculate the energies. Example 1: Manufacturing the OLEDs

[0217] Pretreatment for OLED production: Glass plates coated with 50 nm thick structured ITO (indium tin oxide) are first treated with an oxygen plasma, followed by an argon plasma, before coating. These plasma-treated glass plates form the substrates onto which the OLEDs are applied.

[0218] OLEDs generally have the following layer structure: substrate / hole injection layer (HIL) / hole transport layer (HTL) / electron blocking layer (EBL) / emission layer (EML) / optional hole blocking layer (HBL) / electron transport layer (ETL) / optional electron injection layer (EIL), and finally a cathode. The cathode is formed by a 100 nm thick aluminum layer.

[0219] All materials are thermally vapor-deposited in a vacuum chamber. The emission layer always consists of at least one matrix material (also called host material), or in the context of the invention, at least two matrix materials, and an emitting dopant (dopant, emitter), which is mixed into the matrix material(s) in a specific volume fraction by co-evaporation. Analogously, the electron-transport layer can also consist of a mixture of two materials.

[0220] OLEDs are characterized as standard. For this purpose, the electroluminescence spectra and current-voltage-luminance (IUL) characteristics are measured. The EQE and current efficiency (SE) (in cd / A) are calculated from these values. The SE calculation assumes a Lambertian radiation pattern.

[0221] The electroluminescence spectra are determined at a luminance of 1000 cd / m², and the CIE 1931 x and y color coordinates are calculated from them. U1000 in Table 7 refers to the voltage required for a luminance of 1000 cd / m². SE1000 and EQE1000 refer to the current efficiency and external quantum efficiency, respectively, achieved at 1000 cd / m².

[0222] The lifetime LD is defined as the time after which the luminance drops from an initial luminance to a certain percentage L1 (in cd / m2) when operating at a constant current density j0 in mA / cm2. A value of L1 = 95% in Table 7 means that the lifetime specified in column LD corresponds to the time (in hours) after which the luminance drops to 95% of its initial value. Use of mixtures according to the invention in OLEDs

[0223] In the following examples V1 to V11 and B1 to B26 (see Tables 6 and 7), the use of the material combinations according to the invention in OLEDs is presented in comparison to material combinations from the prior art.

[0224] The structure of the OLEDs can be found in Table 6. The materials required for the fabrication of the OLEDs are shown in Table 8, unless previously described. The device data of the OLEDs are described in Table 7.

[0225] A specification such as VG1:H2:TER5 (57%:40%:3%) 35nm means that the reference material 1 is present in a volume fraction of 57% as host material 1, the compound H2 as host material 2 in a fraction of 40% and TER5 in a fraction of 3% in a 35nm thick layer.

[0226] Examples V1 to V11 are comparative examples with an electron-transporting host according to the prior art in combination with the host materials 2 mentioned. When comparing the examples according to the invention with the corresponding comparative examples, it is clearly evident that the examples according to the invention each show a significant advantage in device lifetime. Table 6: e.g. HIL thickness HTL thickness EBL thickness EML thickness HBL thickness ETL thickness EIL Dick e V1 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm VG1:H2:TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B1 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E2:H2:TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm V2 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm VG2:H10:TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B2 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E16:H10 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm V3 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm VG3:H2 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm V4 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm VG4:H2 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm V5 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm VG5:H11 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm V6 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm VG6:H2 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm V7 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm VG7:H2 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm V8 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm VG8:H2 :TER 5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B3 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E4:H2: TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B4 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E1:H2 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm V9 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm VG9:H2: TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm V10 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm VG10 :IC3:TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B5 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E5:H2 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm V11 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm VG11:H2 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B6 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E6:H2:TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B7 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E7:H2:TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B8 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E8:H2 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B9 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E9:H2 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B10 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E10:H2 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B11 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E11:H2 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B12 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E12:H2 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B13 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E13:H2 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B14 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E14:H2 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B15 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E15:H2 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B16 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E1:H1 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B17 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E1:H3 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B18 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E1:H4 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B19 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E1:H5:TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B20 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E1:H6:TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B21 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E1:H7:TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B22 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E1:H8 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B23 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E1:H9 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B24 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E1:H2 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B25 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E6:H2 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm B26 SpMA1:PD1 (95%:5%) 20nm SpMA1 110nm SpMA2 10nm E18:H2 :TER5 (57%:40%:3%) 35nm ST2 10nm ST2:LiQ (50%:50%) 30nm LiQ 1nm Table 7: OLED data Bsp. U1000 (V) SE1000 (cd / A) EQE 1000 (%) CIE x / y bei 1000 cd / m 2< j0 (mA / cm 2< ) L1 (%) LD (h) V1 3.5 28 23.2 0.66 / 0.34 60 95 65 B1 3.4 26 24.7 0.67 / 0.33 60 95 128 V2 3.5 26 20 0.66 / 0.33 60 95 40 B2 3.2 28 24.8 0.67 / 0.33 60 95 110 V3 3.5 29 23.2 0.67 / 0.33 60 95 88 V4 3.6 27 23.1 0.66 / 0.33 60 95 86 V5 3.5 26 23.7 0.67 / 0.34 60 95 75 V6 3.6 28 22,3 0.66 / 0.34 60 95 50 V7 3.7 28 21.7 0.66 / 0.33 60 95 74 V8 3.6 26 22.4 0.66 / 0.34 60 95 53 B3 3.2 28 25 0.67 / 0.33 60 95 121 B4 3.3 28 24.4 0.67 / 0.33 60 95 120 V9 3.4 27 21.1 0.66 / 0.33 60 95 71 V10 3.7 27 22.2 0.66 / 0.34 60 95 43 B5 3.3 26 22 0.66 / 0.33 60 95 122 V11 3.2 26 23.2 0.66 / 0.33 60 95 61 B6 3.1 28 24.9 0.66 / 0.34 60 95 114 B7 3.4 27 24.3 0.66 / 0.33 60 95 113 B8 3.5 26 24.2 0.66 / 0.33 60 95 110 B9 3.4 26 23.1 0.66 / 0.34 60 95 115 B10 3.6 27 24.5 0.66 / 0.33 60 95 119 B11 3.7 26 23.3 0.67 / 0.33 60 95 112 B12 3.7 27 23.7 0.66 / 0.33 60 95 112 B13 3.4 28 23.6 0.66 / 0.34 60 95 109 B14 3.6 26 23.7 0.66 / 0.33 60 95 111 B15 3.4 28 24.2 0.66 / 0.33 60 95 117 B16 3.3 26 24.9 0.66 / 0.34 60 95 124 B17 3.4 27 25 0.66 / 0.34 60 95 127 B18 3.4 26 24.5 0.66 / 0.33 60 95 126 B19 3.3 27 24.8 0.67 / 0.33 60 95 132 B20 3.2 26 25 0.66 / 0.33 60 95 135 B21 3.3 26 24.2 0.66 / 0.33 60 95 134 B22 3.2 28 24.8 0.66 / 0.34 60 95 132 B23 3.4 28 23.2 0.66 / 0.33 60 95 130 B24 3.5 28 24.6 0.66 / 0.33 60 95 98 B25 3.5 28 24.8 0.66 / 0.33 60 95 91 B26 3.3 27 23.1 0.66 / 0.33 60 95 114 Table 8: Materials used, if not previously described: PD1 (CAS Reg. No. 1224447-88-4) SpMA1 SpMA2 ST2 LiQ TER5 IC3 VG1 WO20071778 VG2 US2020161564 VG3 WO20071778 VG4 WO19017741 VG5 WO20067657 VG6 WO19083327 VG7 WO18060218 VG8 WO18060307 VG9 WO15105313 VG10 WO19083327 VG11 KR20180041607 Example 2: Synthesis of host materials and their precursors:

[0227] Unless otherwise stated, the following syntheses are carried out under a protective gas atmosphere in dried solvents. The compounds of the invention can be prepared using synthesis methods known to those skilled in the art. a) 2-Chloro-4,8-diphenyl-benzofuro[3,2-d]pyrimidin

[0228]

[0229] 31.4 g (100 mmol) of 2,4-dichloro-8-phenyl-benzofuro[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 of water, and 250 ml of toluene, and stirred under an argon atmosphere. 1.2 g (1 mmol) of tetrakis(triphenylphosphine)palladium is added. 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 MgSO 4 , filtered, and the solvent is removed in vacuo. The residue is purified by column chromatography on silica gel (eluent: DCM / heptane (1:10). The yield is 28 g (80 mmol), corresponding to 80% of theory.

[0230] Analogously, the following connections are made: Material 1 Material 2 Produkt Ausbeute 1a 75% 2a 73% 3a 67% 4a 80% 5a 73% 6a 86% 7a 84% 8a 76% 9a 73% 10a 79% 11a 81% 12a 76% 13a 82% 14a 79% 13a 86% b) 7-(4-Bromodibenzofuran-1-yl)benzo[c]carbazol

[0231]

[0232] Under an inert atmosphere, 37.1 g (100 mmol) of 4-bromo-1-iodo-dibenzofuran, 21.7 g (100 mmol) of 7H-benzo[c]carbazole, 34.55 g (250 mmol) of potassium carbonate, and 1.27 g (20.0 mmol) of copper powder are placed in 350 mL of DMF (N,N-dimethylformamide), rendered inert with argon for a further 15 min, and then stirred at 130 °C for 32 h. The mixture is allowed to cool to room temperature, filtered through a bed of Celite, washed twice with 200 mL of DMF, and the solvent is removed to dryness on a rotary evaporator. The residue is extracted with dichloromethane / water, the organic phase is washed twice with water and once with saturated NaCl solution, and dried over Na 2 SO 4. 150 mL of ethanol are added, the dichloromethane is removed using a rotary evaporator at 500 mbar, and the precipitated solid is filtered off with suction and washed with ethanol. Yield: 31 g (67 mmol, 68%) gray solid; 97% pure according to 1< H NMR.Column chromatography can be used for purification, or common solvents such as ethanol, butanol, acetone, ethyl acetate, acetonitrile, toluene, xylene, dichloromethane, methanol, tetrahydrofuran, n-butyl acetate, 1,4-dioxane, dimethyl sulfoxide, N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone, etc. can be used for recrystallization.

[0233] The following compounds are obtained analogously: Material 1 Material 2 Produkt Ausbeute 1b 87% 2b 88% 3b 85% 4b 79% 5b 76% 6b 87% 7b 64% 8b 86% 9b 83% 10b 84% 11b 87% 12b 89% 13b 82% 14b 81% 15b 67% 16b 64% 17b 60% 18b 61% c) 7-(4-Bromodibenzofuran-1-yl)benzo[c]carbazol

[0234]

[0235] 15.8 g (60 mmol) of 4-bromo-1-fluoro-dibenzofuran, 13.2 g (60 mmol) of 7H-benzo[c]carbazole, and 27.1 g (77 mmol) of cesium carbonate were dissolved in 320 ml of DMSO (dimethyl sulfoxide) under an argon atmosphere. The reaction mixture was stirred under reflux for 24 h. After cooling, the organic phase was separated, washed three times with 200 ml of water, dried over MgSO 4 , filtered, and the solvent was removed in vacuo. The residue was purified by column chromatography on silica gel (eluent: DCM and heptane (1:3)). The yield was 23 g (50 mmol), corresponding to 84% of theory.

[0236] The following compounds are obtained analogously: Material 1 Material 2 product yield 1c 71% 2c 73% 3c 75% d) (1-Benzo[c]carbazol-7-yldibenzofuran-4-yl)boronic acid

[0237]

[0238] 42.8 g (95 mmol) of 7-(4-bromodibenzofuran-1-yl)benzo[c]carbazole was dissolved in 500 mL of THF under an argon atmosphere and then cooled to -78 °C. 10 mL (104 mmol / 2.5 M in hexane) of butyllithium was added dropwise at -78 °C, and the mixture was stirred for two hours. 15 g (144 mmol) of trimethyl borate was then added dropwise at -78 °C, and the mixture was stirred overnight at room temperature. 200 mL of 2N hydrochloric acid was added and stirred for one hour. The organic phase was separated, washed three times with 300 mL of water, dried over MgSO4, filtered, and the solvent was removed in vacuo. The residue was washed with 500 mL of heptane, filtered, and dried. The yield is 31 g (74 mmol), corresponding to 80% of theory.

[0239] The following compounds are obtained analogously: Material 1 product yield 1d 76% 2d 65% 3d 77% 4d 61% 5d 82% 6d 73% 7d 70% 8d 80% 9d 64% 10d 78% 11d 74% 12d 82% 13d 76% 14d 75% 15d 88% 16d 86% 17d 80% 18d 76% 19d 75% 20d 72% e) 2-(1-Benzo[c]carbazol-7-yldibenzofuran-4-yl)-4,8-diphenyl-benzofuro[3,2-d]pyrimidine

[0240]

[0241] 35.6 g (100 mmol) of 2-chloro-4,8-diphenylbenzofuro[3,2-d]pyrimidine, 42.7 g (100 mmol) of 1-benzo[c]carbazol-7-yldibenzofuran-4-yl)boronic acid, and 11.8 g (111 mmol) of sodium carbonate are dissolved in 800 ml of 1,4-dioxane, 800 ml of water, and 250 ml of toluene and stirred under an argon atmosphere. 1.2 g (1 mmol) of tetrakis(triphenylphosphine)palladium is added. 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, filtered, and the solvent is removed in vacuo. The residue is purified by column chromatography on silica gel (eluent: DCM / heptane (1:10)) and finally sublimed under high vacuum. The yield is 54 g (78 mmol), corresponding to 78% of theory.

[0242] The following compounds are obtained analogously: Material 1 Material 2 product yield 1e 77% 2e 71% 3e 69% 4e 78% 5e 65% 6e 86% 7e 87% 8e 84% 9e 82% 10e 87% 12e 63% 13e 85% 14e 61% 15e 82% 16e 80% 17e 84% 18e 60% 19e 62% 20e 83% 21e 81% 22e 64% 23e 85% 24e 83% 25e 80% 26e 63% 27e 69% 28e 77% 29e 75% 30e 81% 31e 64% 32e 76% 33e 79% 34e 65% 35e 61% 36e 62% 37e 65% 38e 71%

Claims

1. Organic electroluminescent device comprising an anode, a cathode and at least one organic layer, comprising at least one light-emitting layer, where the at least one light-emitting layer comprises 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, where the following applies to the symbols and indices used: ring A1 in formula (1) corresponds to the formula (1A) V2 is O or S; ring A2 in formula (1) corresponds to one of the formulae (1B), (1C), (1D), (1E), (1F), (1G) or (1H), which may be substituted by one or more radicals R; V3 is O or S, Rx, Ry and Rz are in each case, independently, an aromatic ring system having 6 to 14 ring atoms or a heteroaromatic ring system having 9 to 14 ring atoms, which may in each case be substituted by one or more radicals R; n is 0, 1, 2 or 3; m is 0, 1, 2, 3 or 4; o is 0, 1 or 2; p1, p2 are 0 or 1 and the sum p1 + p2 is 1; R# is on each occurrence, independently, D, an aryl group having 6 to 12 C atoms, which may be substituted by one or more radicals R, dibenzofuranyl, dibenzothienyl, or carbazolyl, bonded via a C atom, which may be substituted by one or more radicals R and where the N atom of the carbazolyl group is substituted by an aryl group having 6 to 12 C atoms, which may be substituted by one or more radicals R; R* is on each occurrence, independently, D or an aryl group having 6 to 12 C atoms, which may be substituted by one or more radicals R; R is selected on each occurrence, identically or differently, from D, F, CN, a straight-chain alkyl group having 1 to 20 C atoms, a branched or cyclic alkyl group having 3 to 20 C atoms, where one or more non-adjacent CH2 groups may be replaced by R2C=CR2, O or S and where one or more H atoms may be replaced by D, F, or CN, or an aryl group having 6 to 14 C atoms; R2 is selected on each occurrence, identically or differently, from the group consisting of H, D, F, CN, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where one or more non-adjacent CH2 groups may be replaced by O or S and where one or more H atoms may be replaced by D, F, or CN; K, M, if x and y denote 0 and if x1 and y1 denote 0, are in each case, independently of one another, an aromatic ring system having 6 to 40 ring atoms which is unsubstituted or partially or fully deuterated or monosubstituted by R1, or K, M, as soon as the value of x, x1, y and / or y1 denotes 1, in each case, independently of one another, form, together with X or X1, a heteroaromatic ring system having 14 to 40 ring atoms; x, x1 are in each case, independently on each occurrence, 0 or 1; y, y1 are in each case, independently on each occurrence, 0 or 1; X und X1 are in each case, independently of one another on each occurrence, a bond or C(R+)2; R0 is on each occurrence, independently of one another, an unsubstituted or partially or fully deuterated aromatic ring system having 6 to 18 ring atoms, or two substituents R0 can form a ring of the formula (1D); R1 is an aryl group having 6 to 18 C atoms; R+ is on each occurrence, independently of one another, a straight-chain or branched alkyl group having 1 to 4 C atoms and c, d, e and f are, independently of one another, 0, 1 or 2.

2. Organic electroluminescent device according to Claim 1, characterised in that the host material 1 corresponds to one of the formulae (1a), (1b), (1c), (1d), (1e), (1f) or (1g), where the symbols R#, R*, n, m, o, p1, p2, Rx, Ry, Rz, V3 used and ring A1 have a meaning as in Claim 1.

3. Organic electroluminescent device according to Claim 1 or 2, characterised in that V3 denotes O.

4. Organic electroluminescent device according to one or more of Claims 1 to 3, characterised in that the host material 2 corresponds to one of the formulae (2a), (2b) or (2c), where the symbols and indices X, X1, R0, c, d, e and f used have a meaning as in Claim 1 and K and M in compounds of the formula (2a) in each case, independently of one another, denote an aromatic ring system having 6 to 40 ring atoms which is unsubstituted or partially or fully deuterated or monosubstituted by R1; M in compounds of the formula (2b) denotes an aromatic ring system having 6 to 40 ring atoms which is unsubstituted or partially or fully deuterated or monosubstituted by R1; K in compounds of the formula (2b) forms, together with X, a heteroaromatic ring system having 14 to 40 ring atoms and x and y in compounds of the formula (2b) in each case, independently of one another, denote 0 or 1 and the sum of x and y denotes at least 1; and K and M in compounds of the formula (2c) in each case, independently of one another, form, together with X or X1, a heteroaromatic ring system having 14 to 40 ring atoms; and x, x1, y and y1 in compounds of the formula (2c) in each case, independently of one another, denote 0 or 1 and the sum of x and y denotes at least 1 and the sum of x1 and y1 denotes at least 1.

5. Organic electroluminescent device according to one or more of Claims 1 to 4, characterised in that it is an electroluminescent device selected from 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).

6. Organic electroluminescent device according to one or more of Claims 1 to 5, characterised in that this organic layer, besides the light-emitting layer (EML), comprises a hole-injection layer (HIL), a hole-transport layer (HTL), an electron-transport layer (ETL), an electron-injection layer (EIL) and / or a hole-blocking layer (HBL).

7. Organic electroluminescent device according to one or more of Claims 1 to 6, characterised in that the light-emitting layer, besides the at least one host material 1 and the at least one host material 2, comprises at least one phosphorescent emitter.

8. Organic electroluminescent device according to one or more of Claims 1 to 7, characterised in that the organic layer comprises a hole-injection layer (HIL) and / or a hole-transport layer (HTL) whose hole-injecting material and hole-transporting material is a monoamine that does not contain a carbazole unit.

9. Process for the production of a device according to one or more of Claims 1 to 8, characterised in that the organic layer is applied by gas-phase deposition or from solution.

10. Process according to Claim 9, characterised in that, for the production of 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.

11. Process according to Claim 9, characterised in that, for the production of 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.

12. Process according to Claim 9, characterised in that, for the production of 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.

13. Mixture comprising at least one compound of the formula (1) and at least one compound of the formula (2), where the following applies to the symbols and indices used: ring A1 in formula (1) corresponds to the formula (1A) V2 is O or S; ring A2 in formula (1) corresponds to one of the formulae (1B), (1C), (1D), (1E), (1F), (1G) or (1H), which may be substituted by one or more radicals R; V3 is O or S, Rx, Ry and Rz are in each case, independently, an aromatic ring system having 6 to 14 ring atoms or a heteroaromatic ring system having 9 to 14 ring atoms, which may in each case be substituted by one or more radicals R; n is 0, 1, 2 or 3; m is 0, 1, 2, 3 or 4; o is 0, 1 or 2; p1, p2 are 0 or 1 and the sum p1 + p2 is 1; R# is on each occurrence, independently, D, an aryl group having 6 to 12 C atoms, which may be substituted by one or more radicals R, dibenzofuranyl, dibenzothienyl, or carbazolyl, bonded via a C atom, which may be substituted by one or more radicals R and where the N atom of the carbazolyl group is substituted by an aryl group having 6 to 12 C atoms, which may be substituted by one or more radicals R; R* is on each occurrence, independently, D or an aryl group having 6 to 12 C atoms, which may be substituted by one or more radicals R; R is selected on each occurrence, identically or differently, from D, F, CN, a straight-chain alkyl group having 1 to 20 C atoms, a branched or cyclic alkyl group having 3 to 20 C atoms, where one or more non-adjacent CH2 groups may be replaced by R2C=CR2, O or S and where one or more H atoms may be replaced by D, F, or CN, or an aryl group having 6 to 14 C atoms; R2 is selected on each occurrence, identically or differently, from the group consisting of H, D, F, CN, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where one or more non-adjacent CH2 groups may be replaced by O or S and where one or more H atoms may be replaced by D, F, or CN; K, M, if x and y denote 0 and if x1 and y1 denote 0, are in each case, independently of one another, an aromatic ring system having 6 to 40 ring atoms which is unsubstituted or partially or fully deuterated or monosubstituted by R1, or K, M, as soon as the value of x, x1, y and / or y1 denotes 1, in each case, independently of one another, form, together with X or X1, a heteroaromatic ring system having 14 to 40 ring atoms; x, x1 are in each case, independently on each occurrence, 0 or 1; y, y1 are in each case, independently on each occurrence, 0 or 1; X und X1 are in each case, independently of one another on each occurrence, a bond or C(R+)2; R0 is on each occurrence, independently of one another, an unsubstituted or partially or fully deuterated aromatic ring system having 6 to 18 ring atoms, or two substituents R0 can form a ring of the formula (1D); R1 is an aryl group having 6 to 18 C atoms; R+ is on each occurrence, independently of one another, a straight-chain or branched alkyl group having 1 to 4 C atoms and c, d, e and f are, independently of one another, 0, 1 or 2.

14. Mixture according to Claim 13, characterised 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.

15. Formulation comprising a mixture according to Claim 13 or 14 and at least one solvent.