WO2026022016A1 - Materials for organic light-emitting devices - Google Patents

Abstract

The present invention relates to OLED materials for use in electronic devices, in particular in organic light-emitting devices, and to electronic devices, in particular organic light-emitting devices, which contain these OLED materials.

Description

Foreignfiling_text P24-134.doc - 1 - Materials for Organic Light-Emitting Devices The present invention relates to OLED materials for use in electronic devices, in particular in organic light-emitting devices, as well as electronic devices, in particular organic light-emitting devices, containing these OLED materials. In organic electroluminescent devices (OLEDs), phosphorescent metal-organic complexes are frequently used as emitting materials. In general, there is still room for improvement in OLEDs, especially in OLEDs that exhibit triplet emission (phosphorescence), for example with regard to efficiency, operating voltage, and lifetime. The properties of phosphorescent OLEDs are not solely determined by the triplet emitters used. Here, the other materials used, such as matrix materials or charge transport materials, are also of particular importance. Improvements to these materials can therefore also lead to improvements in the OLED properties. 20 In addition, many electroluminescent devices comprise, besides an emission layer, further layers, such as one or more hole injection layers, hole transport layers, hole blocking layers, electron transport layers, electron injection layers, exciton blocking layers, electron blocking layers, and/or 25 charge-generation layers. These layers have a significant influence on the performance of electroluminescent devices. Especially for charge transport materials, for example electron transport materials, there is a need for materials with a low refractive index (RI). A reduced refractive index of the electron transport layer leads to improved light extraction and thus to improved external quantum efficiency. The object of the present invention is to provide compounds suitable for use in an OLED, in particular Foreignfiling_text P24-134.doc - 2 - as a matrix material for phosphorescent emitters or as an electron transport material, and lead to good properties there. In particular, it is the object of the present invention to provide materials with a low refractive index for use in an electron transport layer, which thereby lead to improved extraction. 5 In general, compounds of the general formula [RSiO3/2]n with n = 6, 8, 10 or 12 are known under the generic term silsesquioxanes. Surprisingly, it was found that certain 10 silsesquioxane derivatives, described in more detail below, solve the problem described above and are well suited for use in OLEDs. In particular, the OLEDs exhibit a long lifetime, high efficiency and low operating voltage. Furthermore, the materials have a lower refractive index than materials that are usually used in electron transport layers. 15 These compounds, as well as electronic devices, in particular organic electroluminescent devices containing these compounds, are therefore the subject of the present invention. 20 US 9,755,165 discloses the use of silsesquioxane derivatives in the hole transport layer of an OLED. Silsequioxane derivatives suitable for use in an electron transport layer are not disclosed. 25 US 11,183,649 describes an OLED which includes a performance enhancement layer with a refractive index ≤ 1.6 at a wavelength of 1200 nm as an additional layer between the electron transport layer and the cathode, and discloses, among other materials for use in this layer, alkyl- or aryl-substituted 30 silsesquioxane derivatives, in particular compounds substituted with fluorinated alkyl or aralkyl groups. This layer additionally contains an n-doped ion. Compared to the standard OLED structure, this structure has the disadvantage that the use of an additional layer results in a significantly more complex device structure. Furthermore, the use of fluorinated alkyl or aryl Foreignfiling_text P24-134.doc - 3 - groups are disadvantageous from an environmental point of view, and a ban on certain fluorine-substituted alkyl groups (PFAS) is currently being discussed. The present invention therefore relates to a compound according to the following formula (1), 5 (R')7Si8O12-Ar-ETU Formula (1) wherein the following applies to the symbols used: 10 ETU is an electron-transporting unit selected from the group consisting of triazine, pyrimidine, quinoxaline, quinazoline, benzoquinazoline, benzoquinoxaline, benzimidazole, diazadibenzofuran, diazadibenzothiophene and diazacarbazole, wherein these groups may each be partially or completely deuterated 15 and/or substituted by one or more R groups; Ar is a bivalent aromatic or heteroaromatic ring system with 5 to 30 aromatic ring atoms, each of which may be partially or completely deuterated and/or substituted by one or more 20 R 1 residues; R' is the same or different in each occurrence F, OR 1 , a straight-chain alkyl group with 1 to 20 C atoms or a branched or cyclic alkyl group with 3 to 20 C atoms, wherein the alkyl group 25 may in each case be partially or completely deuterated and/or substituted with one or more R 1 residues, wherein one or more non-adjacent CH2 groups may be replaced by Si(R 1 )2, C=O, NR 1 , O, S or CONR 1 , or an aromatic ring system with 6 to 12 aromatic ring atoms, 30 which may in each case be partially or completely deuterated and/or substituted with one of the several R 1 residues; R is the same or different in each occurrence: H, D, F, N(R 1 )2, CN, NO2, OR 1 , SR 1 , COOR 1 , C(=O)N(R 1 )2, Si(R 1 )3, B(OR 1 )2, C(=O)R 1 , 35 P(=O)(R 1 )2, S(=O)R 1 , S(=O)2R 1 , OSO2R 1 , a straight-chain alkyl- Foreignfiling_text P24-134.doc - 4 - group with 1 to 20 C atoms or an alkenyl or alkynyl group with 2 to 20 C atoms or a branched or cyclic alkyl group with 3 to 20 C atoms, wherein the alkyl, alkenyl or alkynyl group may each be substituted with one or more R1 residues, wherein one or more non-adjacent CH2 groups 5 may be replaced by Si( R1 )2, C=O, NR1 , O, S or CONR1 , or an aromatic or heteroaromatic ring system with 5 to 40 aromatic ring atoms, which may be substituted with one of the several R1 residues; wherein two R residues may also form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system; R1 is the same or different in each occurrence: H, D, F, Cl, Br, I, N( R2 )2, CN, NO2, OR2 , SR2 , Si( R2 )3, B( OR2 )2, C(=O) R2 , P(=O)( R2 )2, S(=O) R2 , S(=O) 2R2 , OSO2R2 , a straight-chain alkyl group with 1 to 15-20 carbon atoms, or an alkenyl or alkynyl group with 2 to 20 carbon atoms, or a branched or cyclic alkyl group with 3 to 20 carbon atoms, wherein the alkyl, alkenyl, or alkynyl group may each be substituted with one or more R2 substituents, wherein one or more non-adjacent CH2 groups are replaced by Si( R2 )2. C=O, 20 NR 2 , O, S or CONR 2 may be replaced and wherein one or more H atoms in the alkyl, alkenyl or alkynyl group may be replaced by D, F, Cl, Br, I or CN, or an aromatic or heteroaromatic ring system with 5 to 40 aromatic ring atoms, each of which may be substituted by one or more R 2 groups 25; wherein two or more R 1 groups may form an aliphatic, aromatic or heteroaromatic ring system; R 2, in each occurrence, is either the same or different from H, D, F, CN or an 30 aliphatic, aromatic or heteroaromatic organic residue, in particular a hydrocarbon residue, with 1 to 20 C atoms, in which one or more H atoms may also be replaced by F. 35 Foreignfiling_text P24-134.doc - 5 - The unit (R')7Si8O12- in the compound according to the invention is a silsesquioxane with eight silicon atoms and has the following structure: 5 . 10 Here, the dashed bond describes the bond to the unit -Ar-ETU in formula (1) and R' has the meanings listed above. An aryl group according to this invention contains 6 to 40 C atoms; a 15 heteroaryl group according to this invention contains 2 to 40 C atoms and at least one heteroatom, provided 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., benzene, or a simple heteroaromatic cycle, for example, pyridine, pyrimidine, thiophene, etc., or a fused (fused) aryl or heteroaryl group, for example, naphthalene, anthracene, phenanthrene, quinoline, isoquinoline, etc. Aromatic compounds linked to each other by single bonds, such as biphenyl, are not referred to as aryl or heteroaryl groups, but rather as an aromatic ring system. An aromatic ring system within the meaning of this invention contains 6 to 60 carbon atoms, preferably 6 to 40 carbon atoms, in the ring system. A heteroaromatic ring system according to this invention contains 2 to 60 carbon atoms, preferably 2 to 40 carbon atoms, and at least one heteroatom in the ring system, provided that the sum of carbon atoms and heteroatoms is at least 5. The heteroatoms are preferably selected from nitrogen, oxygen, and/or sulfur. An aromatic or heteroaromatic ring system according to this invention is understood to be a system Foreignfiling_text P24-134.doc - 6 - which does not necessarily contain only aryl or heteroaryl groups, but in which several aryl or heteroaryl groups may also be linked by a non-aromatic unit, such as a C, N, or O atom. Likewise, systems in which two or more aryl or heteroaryl groups are directly linked to each other 5, such as biphenyl, terphenyl, bipyridine, or phenylpyridine, are to be understood as aromatic ring systems within the meaning of this invention. This also applies to systems in which two or more aryl groups are linked, for example, by a short alkyl group 10. Preferred aromatic or heteroaromatic ring systems are simple aryl or heteroaryl groups, as well as groups in which two or more aryl or heteroaryl groups are directly linked together, for example biphenyl or bipyridine, as well as fluorene or spirobifluorene. Within the scope of the present invention, the term alkyl group includes both linear and branched and/or cyclic alkyl groups, wherein cyclic alkyl groups can be monocyclic, bicyclic, tricyclic, or oligocyclic. The same applies to alkenyl and alkynyl groups. 20 Within the scope of the present invention, the following are preferably used as the group 25 above: methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl, neo-pentyl, cyclopentyl, n-hexyl, neo-hexyl, cycloheptyl, n-heptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, ethenyl, propenyl, butenyl, Pentenyl, cyclopentenyl, 30 hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl or octynyl. Among an alkoxy group OR 1 with 1 to 40 carbon atoms, preference is given to methoxy, trifluoromethoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy, n-pentoxy, s-pentoxy, 2-methyl-35 butoxy, n-hexoxy, cyclohexyloxy, n-heptoxy, cycloheptyloxy, n-octyloxy, Foreignfiling_text P24-134.doc - 7 - Cyclooctyloxy, 2-ethylhexyloxy, pentafluorethoxy and 2,2,2-trifluorethoxy understood. A thioalkyl group SR 1 with 1 to 40 carbon atoms includes, in particular, methylthio, ethylthio, n-propylthio, i-propylthio, n-butylthio, i-butylthio, s-butylthio, t-butylthio, n-pentylthio, s-pentylthio, n-hexylthio, Cyclohexylthio, n-heptylthio, cycloheptylthio, n-octylthio, cyclo-5octylthio, 2-ethylhexylthio, trifluoromethylthio, pentafluoroethylthio, 2,2,2-trifluoroethylthio, ethenylthio, propenylthio, butenylthio, pentenylthio, cyclopentenylthio, hexenylthio, cyclohexenylthio, heptenylthio, cycloheptenylthio, octenylthio, cyclooctenylthio, ethynylthio, propynylthio, Butynylthio, pentynylthio, hexynylthio, heptynylthio, or octynylthio are understood. In general, alkyl, alkenyl, alkynyl, alkoxy, or thioalkyl groups according to the present invention can be straight-chain, branched, or cyclic, wherein one or more non-adjacent CH2 groups can be replaced by the groups mentioned above; furthermore, one or more H atoms can also be replaced by D, F, Cl, Br, I, CN, or NO2, preferably by D, F, or CN. An aromatic or heteroaromatic ring system with 5–60 aromatic ring atoms, which may each be further substituted with the aforementioned R1 substituents, is understood to include, in particular, groups derived from benzene, naphthalene, anthracene, benzanthracene, phenanthrene, pyrene, chrysene, perylene, fluoranthene, naphthacene, pentacene, benzopyrene, biphenyl, biphenylene, terphenyl, triphenylene, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, cis- or trans-indenofluorene, cis- or trans-indenocarbazole, cis- or trans-indolocarbazole, truxene, isotruxene, spirotruxene, spiroisotruxene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, Isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenothiazine, phenoxazine, 30 pyrazole, indazole, imidazole, Benzimidazole, naphthimidazole, phenanthrimidazole, pyridimidazole, pyrazinimidazole, quinoxalinimidazole, oxazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, 1,2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, hexaazatriphenylene, benzopyridazine, pyrimidine, benzopyrimidine, quinazoline, quinoxaline, 1,5-diaza-35 anthracene, 2,7-diazapyrene, 2,3-diazapyrene, 1,6-diazapyrene, 1,8-diaza- Foreignfiling_text P24-134.doc - 8 - pyrene, 4,5-diazapyrene, 4,5,9,10-tetraazaperylene, pyrazine, phenazine, phenoxazine, phenothiazine, fluorubin, naphthyridine, azacarbazole, benzocarboline, phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,3,5-5 triazine, 1,2,4-triazine, 1,2,3-Triazine, tetrazole, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine, purine, pteridine, indolizine, and benzothiadiazole, or groups derived from combinations of these systems. The phrase "two or more residues can form a ring" in the context of this description means, among other things, that the two residues are linked to each other by a chemical bond with the formal elimination of two hydrogen atoms. This is illustrated by the following scheme: Ring formation = residues RR R H3 C C2H5 H2 C CH 2 CH 2 . Similarly, the formation of a fused aromatic ring is possible if two substituents R, each representing an alkenyl group, are linked to each other by a chemical bond with the formal elimination of two hydrogen atoms. 25 Furthermore, the above formulation should also be understood to mean that if one of the two residues represents hydrogen, the second residue binds to the position to which the hydrogen atom was bonded, forming a ring. This is illustrated by the following scheme: 30 Ring formation = of the residues RR RH CH CH 3 2 . 35 Foreignfiling_text P24-134.doc - 9 - The compounds according to the invention can also be partially or completely deuterated. According to the invention, the compounds have an electron transporting unit (ETU) 5 which is linked to the silsesquioxane (R')7Si8O12- via an aromatic or heteroaromatic linker Ar and which is selected from the group consisting of triazine, pyrimidine, quinoxaline, quinazoline, benzoquinazoline, benzoquinoxaline, benzimidazole, diazadibenzofuran, diazadibenzothiophene and diazacarbazole, wherein these groups can each be partially 10 or completely deuterated and/or substituted by one or more R groups. In a preferred embodiment of the invention, the unit ETU is selected from the structures of the following formulas (ETU-1) to (ETU-13), 15 RRR NR RR RNRNN NNNN NR RR 20 (ETU-1) (ETU-2) (ETU-3) (ETU-4) RRRRRRRRNRRNRRNNR 25 N N RR ( ETU-5) (ETU-6) (ETU-7) RRRRRRRR 30 RNRRRRRRRNN N RRRN N (ETU-10) (ETU-8) (ETU-9) 35 Foreignfiling_text P24-134.doc - 10 - 5 where R has the meanings mentioned above, E stands for O, S, or NR, and the dashed line indicates the bond to Ar. Preferably, a maximum of two of the explicitly drawn residues R represent a residue other than H or D. 10 Preferred structures ETU are the structures of the following formulas (ETU-1a) to (ETU-13a), 15 20 25 30 35 Foreignfiling_text P24-134.doc - 11 - where the symbols used have the meanings mentioned above and the structures may also be partially or completely deuterated. The explicitly drawn residues R preferably represent, in each instance, an aromatic or heteroaromatic ring system with 6 to 30 aromatic ring atoms, each of which may also be partially or completely deuterated and/or substituted with one or more residues R1 . If E stands for NR, then the residue R that bonds to the N atom preferably represents an aromatic or heteroaromatic ring system with 6 to 30 aromatic ring atoms, each of which may also be partially or completely deuterated and/or substituted with one or more residues R1 . In a preferred embodiment of the invention, R is selected in each occurrence, either identically or differently, from the group consisting of 15 H, D, F, CN, OR 1 , a straight-chain alkyl group with 1 to 10 C atoms or an alkenyl group with 2 to 10 C atoms or a branched or cyclic alkyl group with 3 to 10 C atoms, wherein the alkyl or alkenyl group may each be substituted with one or more R 1 residues, but preferably is unsubstituted, or an aromatic 20 or heteroaromatic ring system with 6 to 30 aromatic ring atoms, which may be substituted with one or more R 1 residues; in this respect, two adjacent R residues may also form an aliphatic, aromatic or heteroaromatic ring system together. Particularly preferably, R is selected, in each occurrence, either the same or different from the group consisting of H, D, a straight-chain alkyl group with 1 to 6 carbon atoms, in particular with 1, 2, 3 or 4 carbon atoms, a straight-chain alkenyl group with 2 to 4 carbon atoms, in particular with 2 carbon atoms, or a branched or cyclic alkyl group with 3 to 6 carbon atoms, wherein the alkyl or alkenyl group may be substituted with one or more R 1  groups, but is preferably unsubstituted, or an aromatic or heteroaromatic ring system with 6 to 24 aromatic ring atoms, which may be substituted with one or more R 1 groups. Most preferably, R is selected, in each occurrence, either the same or different from the group consisting of H, D, or an aromatic or heteroaromatic Foreignfiling_text P24-134.doc - 12 - tic ring system with 6 to 18 aromatic ring atoms, in particular with 6 to 13 aromatic ring atoms, each of which may be substituted with one or more R 1 residues. Suitable aromatic or heteroaromatic ring systems R are selected from phenyl, biphenyl, in particular ortho-, meta- or para-biphenyl, terphenyl, in particular ortho-, meta-, para- or branched terphenyl, quaterphenyl, in particular ortho-, meta-, para- or branched quaterphenyl, fluorene, which may be linked via the 1-, 2-, 3- or 4-position, spirobifluorene, which may be linked via the 1-, 2-, 3- or 4-position, naphthalene, which may be linked via the 1- or 2-position, indole, benzofuran, benzothiophene, carbazole, which may be linked via the 1-, 2-, 3- or 4-position, dibenzofuran, which may be linked via the 1-, 2-, 3- or 4-position, dibenzothiophene, which may be linked via the 1-, 2-, 3- or 4-position linked 15 may be indenocarbazole, indolocarbazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, quinazoline, quinoxaline, benzimidazole, phenanthrene, triphenylene or a combination of two or three of these groups, each of which may be partially or completely deuterated and/or substituted with one or more R 1 residues 20. Aromatic ring systems or carbazole are preferred. The aromatic or heteroaromatic groups R are preferably chosen from the groups of the following formulas R-1 to R-83, 25 30 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 1 R 1 R 1 R 1 35 R R -5 R-6 R-7 Foreignfiling_text P24-134.doc - 14 - 5 10 R 1 R 1 R 1 A 1 Ar 1 R 1 R 1 R 1 R 1 R 1 R 1 A 1 R 1 R 1 m N A 1 R 1 R 1 R 1 R 1 R 1 R 1 15 R 1 1 1 R 1 R 1 A R1 1 1 R 1 A R1 1 R1 R 1 R RR R-29 R-31 R-30 A r 1 1 1 1 1 1 1 m R R 1 1 1 R R RR 1 R R RR NA 1 A 1 R 1 R 1 R 1 R 1 R 1 A 1 1 A 1 R1 R1 1 A 1 20 R1 R1 R1 R R1 R1 R R 1 R -32R - 33R1R1 R 1 R-34 25 30 35 Foreignfiling_text P24-134.doc - 16 - 5 10 15 20 25 R 1 R 1 R 1 R 1 R 1 R 1 30 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R-69 R-70 R-71 R-72 35 Foreignfiling_text P24-134.doc - 17 - 5 10 15 20 where R 1 has the meanings mentioned above, the dashed bond represents the bond of the group to ETU, and furthermore: 25 Ar 1 is, in each occurrence, the same or different, a bivalent aromatic or heteroaromatic ring system with 6 to 18 aromatic ring atoms, each of which may be substituted with one or more R 1 residues; 30 A 1 is, in each occurrence, the same or different, C(R 1 )2, NR 1 , O or S; or, in formulas R-40, R-41 and R-42, is, in each occurrence, the same or different, a single bond, C(R 1 )2, NR 1 , O or S; n is 0 or 1, where n = 0 means that no group A 1 is bonded at this position and instead residues R 1 are bonded to the corresponding carbon atoms; Foreignfiling_text P24-134.doc - 18 - m is 0 or 1. If the above-mentioned groups R-1 to R-83 have multiple groups A 1 , then all combinations from the definition of 5 A 1 are possible. Preferred embodiments are then those in which one group A 1 stands for NR 1 and the other group A 1 for C(R 1 )2, or in which both groups A 1 stand for NR 1 , or in which both groups A 1 stand for O. In a particularly preferred embodiment of the invention, in groups R, which have multiple groups A 1 , at least 10 groups A 1 stand for C(R 1 )2 or for NR 1 . If A1 represents NR1 , the substituent R1 bonded to the nitrogen atom preferably represents an aromatic or heteroaromatic ring system with 5 to 24 aromatic ring atoms, which may also be substituted by one or more R2 groups. In a particularly preferred embodiment, this substituent R1 represents, in each instance, an aromatic or heteroaromatic ring system with 6 to 24 aromatic ring atoms, preferably with 6 to 12 aromatic ring atoms, which does not contain any fused aryl groups or heteroaryl groups in which two or more aromatic or heteroaromatic 6-ring groups are directly fused to one another, and which may also be substituted by one or more R2 groups. Particularly preferred are phenyl, biphenyl, terphenyl, and quaterphenyl with linkage patterns as listed above for R-1 25 to R-11, wherein these structures may be substituted by one or more R- 2 groups, but are preferably unsubstituted. Where A -1 represents C(R -1 )2, the substituents R- 1 bonded to this carbon atom preferably represent, either identically or differently in each occurrence, a linear alkyl group with 1 to 10 carbon atoms, or a branched or cyclic alkyl group with 3 to 10 carbon atoms, or an aromatic or heteroaromatic ring system with 5 to 24 aromatic ring atoms, which may also be substituted by one or more R- 2 groups. Most preferably, R -1 represents a Foreignfiling_text P24-134.doc - 19 - methyl group or for a phenyl group. The R1 residues can also form a ring system with each other, leading to a spiro system. Preferred embodiments for the Ar group are described below. In a preferred embodiment of the invention, Ar 5 is a bivalent aromatic or heteroaromatic ring system with 6 to 18 aromatic ring atoms, each of which may be partially or completely deuterated and/or substituted by one or more R1 residues. Particularly preferably, Ar represents an aromatic ring system with 6 to 12 aromatic ring atoms or a heteroaromatic ring system with 6 to 13 aromatic ring atoms, each of which may be partially or completely deuterated and/or substituted by one or more R1 residues, preferably non-aromatic R1 residues. 15 Preferred bivalent aromatic or heteroaromatic ring systems Ar are selected from phenylene, biphenyl, in particular ortho-, meta- or para-biphenyl, terphenyl, in particular ortho-, meta-, para- or branched terphenyl, fluorene, spirobifluorene, carbazole, dibenzofuran or dibenzothiophene, wherein these groups may each be partially or completely deuterated and/or substituted with one or more R1 groups, preferably non-aromatic R1 groups. Ar is particularly preferably phenylene or biphenyl, wherein these groups may each be partially or completely deuterated and/or substituted with one or more R1 groups, preferably non-aromatic R1 groups. Ar is most preferably phenylene or biphenyl, which may each also be partially or completely deuterated. Preferred groups Ar are therefore the groups of the following formulas 30 (Ar-1) to (Ar-12), 35 Foreignfiling_text P24-134.doc - 20 - R 1 R 1 R 1 R 1 R 1 R 1 * # * R 1 * R 1 R 1 R 1 R 1 # # R 1 (Ar-1) (Ar-2) (Ar-3) 5 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 * # * R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 # (Ar-4)(Ar-5) 10 R 1 R 1 R 1 R 1 R 1 R 1 R 1 R 1 * R 1 * R 1 * R 1 R 1 R 1 R 1 R 1 1 1 # R 1 RR (Ar-6) R 1 R 1 R 1 R 1 15 R 1 # R 1 # (Ar-7) (Ar-8) R 1 R 1 R 1 R 1 R 1 R 1 * R 1 * R 1 * R 1 R 1 R 1 R 1 20 R 1 R 1 R 1 # R 1 R 1 R 1 R 1 R 1 R 1 R 1 # R 1 R 1 # (Ar-9) (Ar-10) (Ar-11) 25 30 where the symbols used have the meanings mentioned above, the dashed bond marked with * represents the bond to silicon and the dashed bond marked with # represents the bond to ETU. Preferably, a maximum of two R 1 residues represent 35 residues other than H or D. Particularly preferably, a maximum of one R 1 residue represents Foreignfiling_text P24-134.doc - 21 - for a residue other than H or D, and particularly preferably all residues R 1, whether equal or different, represent H or D at every occurrence. Particularly preferably, Ar therefore represents a group according to one of the following formulas (Ar-1a) to (Ar-12a), 5 * # * * # # (Ar-1a) (Ar-2a) (Ar-3a) 10 * # * (Ar-4a) (Ar-5a) # * * * 15 # (Ar-6a) (Ar-7a) # # (Ar-8a) 20 * * * * # # (Ar-9a) # (Ar-10a) # (Ar-12a) (Ar-11a) 25 where the symbols used have the meanings mentioned above and the structures may be partially or completely deuterated. 30 Preferred embodiments of the substituents R' bonded to the silicon atoms of the silsesquioxane are described below. Preferably, R' is selected as the same or different from OR 1 in each instance, where R 1 in the group OR 1 represents a straight-chain alkyl group with 1 to 4 carbon atoms or a branched or cyclic alkyl group with 3 to 35 6 carbon atoms, wherein the alkyl group may also be partially or fully Foreignfiling_text P24-134.doc - 22 - can be permanently deuterated, or a straight-chain alkyl group with 1 to 6 carbon atoms, or a branched or cyclic alkyl group with 3 to 6 carbon atoms, wherein the alkyl group can be partially or completely deuterated. Particularly preferably, R' is the same or different in each occurrence for a straight-chain alkyl group with 1, 2, 3, 5 or 4 carbon atoms, in particular methyl, or a branched alkyl group with 3, 4 or 5 carbon atoms, in particular isopropyl, tert-butyl or neopentyl, wherein the alkyl group can be partially or completely deuterated. 10 In a further preferred embodiment of the invention, R 1 is selected, either the same or different at each occurrence, from the group consisting of H, D, F, CN, OR 2 , a straight-chain alkyl group with 1 to 10 C atoms or an alkenyl group with 2 to 10 C atoms or a branched or cyclic alkyl group with 3 to 10 C atoms, wherein the alkyl or alkenyl group may each be substituted with one or more R 2 residues and wherein one or more non-adjacent CH2 groups may be replaced by O, or an aromatic or heteroaromatic ring system with 6 to 30 aromatic ring atoms, each of which may be substituted by one or more R 2 residues; 20 wherein two or more R 1 residues may together form an aliphatic ring system. In a particularly preferred embodiment of the invention, R1 is selected, either the same or different in each occurrence, from the group consisting of H, a straight-chain alkyl group with 1 to 6 carbon atoms, in particular with 1, 2, 3 or 4 carbon atoms, or a branched or cyclic alkyl group with 3 to 6 carbon atoms, wherein the alkyl group may be substituted with one or more R2 groups, but preferably is unsubstituted, or an aromatic or heteroaromatic ring system with 6 to 24 aromatic ring atoms, each of which may be substituted by one or more R2 groups, but preferably is unsubstituted. In a further preferred embodiment of the invention , R2 is selected, either the same or different in each occurrence, from the group consisting of H, F, an alkyl group with 1 to 4 carbon atoms or an aryl group with 6 to 10 carbon atoms, which is coupled with a Foreignfiling_text P24-134.doc - 23 - The alkyl group can be substituted with 1 to 4 carbon atoms, but is preferably unsubstituted. In compounds according to the invention, which are processed by vacuum evaporation, the alkyl groups preferably have no more than 5 carbon atoms, particularly preferably no more than 4 carbon atoms, and most preferably no more than 1 carbon atom. For compounds processed from solution, compounds substituted with alkyl groups, in particular branched alkyl groups, with up to 10 carbon atoms, or substituted with oligoarylene groups, for example ortho-, meta-, para- or branched terphenyl or quaterphenyl groups, are also suitable. When the compounds according to the invention are used as a matrix material for a phosphorescent emitter or as a matrix material in hyperphosphorescent OLEDs or in a layer directly adjacent to a phosphorescent layer, it is further preferred if the compound does not contain any fused aryl or heteroaryl groups Ar or R in which more than two six-membered rings are directly fused to one another. Phenanthrene and triphenylene are exceptions to this, as they may be preferred despite the presence of fused aromatic six-membered rings due to their high triplet energy. The preferred embodiments mentioned above can be combined arbitrarily within the limitations defined in claim 1. In a particularly preferred embodiment of the invention, the above-mentioned preferences occur simultaneously. Examples of suitable compounds according to the embodiments listed above are those listed in Table 1 below. Foreignfiling_text P24-134.doc - 24 - 5 1 2 10 3 4 15 20 5 6 25 7 8 30 35 9 10 Foreignfiling_text P24-134.doc - 25 - 5 11 12 10 15 13 14 20 15 16 25 30 17 18 35 Foreignfiling_text P24-134.doc - 26 - 5 19 20 10 15 21 22 20 23 24 25 30 25 26 The compounds (5) according to the invention can be obtained according to the reaction sequence shown in Scheme 35 1. Starting from the Foreignfiling_text P24-134.doc - 27 - The halogenaryl-functionalized polyhedral octasilsesquioxane POSS (3) can be prepared by base-mediated reaction in step 1 with a halogenaryl-functionalized trichlorosilane (2) according to S. Morimoto et al., Bull. Chem. Soc. Jpn., 2018, 91, 1390 or with a halogenaryl-functionalized trialkoxysilane (2) according to I. Blanco et al., Journal of Thermal Analysis and Calorimetry (2012), 5 108(2), 807, using a so-called "corner capping reaction". The halogenaryl-functionalized POSS (3) can be converted to the boranylaryl-functionalized POSS (4) in a borylation reaction (step 2). The borylation of POSS (3) to POSS (4) can be carried out either by lithiation followed by reaction with a boric acid ester or by palladium-catalyzed reaction of POSS (3) with an alkyldiborane, preferably B₂Pin₂, in the presence of a base, preferably potassium acetate. In steps 3 and 4, respectively, POSS (3) and POSS (4) can be converted to the POSS (5) according to the invention by CC coupling reactions known to those skilled in the art, preferably the Suzuki coupling, with aryl or heteroarylboronic acids or halides or triflates known from the literature in the presence of a base, a palladium compound, a phosphine, and a solvent or solvent mixture. Scheme 1: 25 30 35 Foreignfiling_text P24-134.doc - 28 - For processing the compounds according to the invention from the liquid phase, for example by spin coating or by printing processes, formulations of the compounds according to the invention are required. These formulations can be, for example, solutions, dispersions 5 or emulsions. It may be preferred to use mixtures of two or more solvents for this purpose. A further object of the present invention is therefore a formulation containing at least one compound according to the invention and at least one further compound. The further compound can be, for example, a further matrix material 10 and/or a phosphorescent emitter and/or a fluorescent emitter and/or an emitter exhibiting TADF (thermally activated delayed fluorescence), and/or a solvent. A further object is the use of the compounds according to the invention 15 in an electronic device, in particular in an organic electroluminescence device. An electronic device within the meaning of the present invention is a device which contains at least one layer which contains at least one organic compound. The component can also contain inorganic materials 20 or layers that are entirely composed of inorganic materials. A further object of the invention is an electronic device, in particular an organic electroluminescent device 25, containing one or more compounds according to the invention. The electronic device is preferably selected from the group consisting of organic electroluminescent devices (OLEDs), organic integrated circuits (O-ICs), organic field-effect transistors 30 (O-FETs), organic thin-film transistors (O-TFTs), organic light-emitting transistors (O-LETs), organic solar cells (O-SCs), dye-sensitized organic solar cells (DSSCs), organic optical detectors, organic photoreceptors, organic field-quench devices (O-FQDs), light-emitting electrochemical cells (LECs), organic laser diodes (O-Lasers), and Foreignfiling_text P24-134.doc - 29 - “organic plasmon emitting devices”, preferably organic electroluminescent devices (OLEDs), particularly preferably phosphorescent or hyperphosphorescent OLEDs. The organic electroluminescent device comprises a cathode, anode 5, and at least one emitting layer. In addition to these layers, it may contain further layers, for example, one or more hole injection layers, hole transport layers, hole blocking layers, electron transport layers, electron injection layers, exciton blocking layers, electron blocking layers, and/or charge-generation layers. Interlayers, which may, for example, have an exciton-blocking function, may also be introduced between two emitting layers. It should be noted, however, that not every one of these layers is necessarily required. The organic electroluminescent device may contain one emitting layer, or it may contain several emitting layers. If several emission layers are present, these preferably exhibit several emission maxima between 380 nm and 750 nm, resulting in overall white emission. This means that 20 different emitting compounds, capable of fluorescence or phosphorescence, are used in the emitting layers. Systems with three emitting layers are particularly preferred, wherein the three layers exhibit blue, green, and orange or red emission. The organic electroluminescent device according to the invention can also be a tandem OLED, especially for white-emitting OLEDs. The compound according to the invention can be used in different layers, depending on the precise structure. In a preferred embodiment of the invention, the compound according to the invention can be used as an electron transport material in an electron transport layer and/or a hole-blocking layer of an organic electroluminescent device. Due to the low refractive index of the compounds according to the invention, they are particularly suitable for use in an electron transport layer, as they lead to improved light extraction there. Foreignfiling_text P24-134.doc - 30 - A hole-blocking layer is typically used as a pure layer of a material. An electron transport layer is typically used either as a pure layer of a material or as a mixture with another electron transport material, for example, as a mixture with triaryltriazine or LiQ (lithium quinolinate). An electron injection layer is typically a pure layer of the electron injection material, for example, LiQ or LiF, as a very thin layer, for example, with a layer thickness in the range of 1 to 5 nm, in direct contact with the cathode. 10 In a further embodiment of the invention, the compound according to the invention can be used in an emitting layer of an organic electroluminescent device as a matrix material for phosphorescent emitters, fluorescent emitters, or for emitters exhibiting TADF (thermally activated delayed fluorescence), particularly for phosphorescent emitters. The large shielding (R')7Si8O12 group largely or completely suppresses the formation of exciplexes between the host and emitter in phosphorescent OLEDs or between the host and phosphorescent sensitizer in hyperphosphorescent OLEDs, which is particularly important for blue and green emitting OLEDs. The organic electroluminescent device can contain one emitting layer or several emitting layers, with at least one emitting layer containing at least one compound according to the invention as a matrix material. Depending on the group ETU, the compounds according to the invention are suitable not only as matrix materials for green, yellow, orange, or red phosphorescent emitters, but also for blue phosphorescent emitters or for blue hyperphosphorescent emission layers. 30 When the compound according to the invention is used as a matrix material for a phosphorescent compound in an emitting layer, it is preferably used in combination with one or more phosphorescent materials (triplet emitters). Phosphorescence 35 within the meaning of this invention is the luminescence from an excited Foreignfiling_text P24-134.doc - 31 - state with higher spin multiplicity understood, 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, in particular all iridium, platinum, and copper complexes, are to be considered phosphorescent compounds. 5 The mixture of the compound according to the invention and the emitting compound contains between 99 and 1 vol%, preferably between 98 and 10 vol%, particularly preferably between 97 and 60 vol%, in particular between 95 and 80 vol% of the compound according to the invention 10 based on the total mixture of emitter and matrix material. Accordingly, the mixture contains between 1 and 99 vol%, preferably between 2 and 90 vol%, particularly preferably between 3 and 40 vol%, in particular between 5 and 20 vol% of the emitter based on the total mixture of emitter and matrix material. 15 Another preferred embodiment of the present invention is the use of the compound according to the invention as a matrix material for a phosphorescent emitter in combination with another matrix material. Suitable matrix materials which can be used in combination with the compounds according to the invention are aromatic ketones, aromatic phosphine oxides or aromatic sulfoxides or sulfones, e.g. according to WO 2004/013080, WO 2004/093207, WO 2006/005627 or WO 2010/006680, triarylamines, carbazole derivatives, etc. B. CBP (N,N-Biscarbazolylbiphenyl) or those in WO 2005/039246, US 25 2005/0069729, JP 2004/288381, EP 1205527, WO 2008/086851 or WO 2013/041176, indolocarbazole derivatives, e.g. according to WO 2007/063754 or WO 2008/056746, indenocarbazole derivatives, e.g. according to WO 2010/136109, WO 2011/000455, WO 2013/041176 or WO 2013/056776, azacarbazole derivatives, e.g. B. according to EP 1617710, EP 30 1617711, EP 1731584, JP 2005/347160, bipolar matrix materials, e.g. according to WO 2007/137725, silanes, e.g. according to WO 2005/111172, azaboroles or boron esters, e.g. according to WO 2006/117052, triazine derivatives, e.g. according to WO 2007/063754, WO 2008/056746, WO 2010/015306, WO 2011/057706, WO 2011/060859 or WO 2011/060877, pyrimidine derivatives, zinc complexes, e.g. B. according to EP 652273 or WO 2009/062578, Foreignfiling_text P24-134.doc - 32 - Diazasilol or tetraazasilol derivatives, e.g. according to WO 2010/054729, diazaphosphole derivatives, e.g. according to WO 2010/054730, bridged carbazole derivatives, e.g. according to WO 2011/042107, WO 2011/060867, WO 2011/088877 and WO 2012/143080, triphenylene derivatives, e.g. according to WO 2012/048781, or dibenzofuran derivatives, e.g. B. according to WO 5 2015/169412, WO 2016/015810, WO 2016/023608, WO 2017/148564 or WO 2017/148565. Likewise, another phosphorescent emitter, which emits at a shorter wavelength than the actual emitter, can be present as a co-host in the mixture, or a compound that does not participate in charge transport or does not participate to a significant extent, as described, for example, in WO 2010/108579. The compounds according to the invention are electron-deficient or electron-transporting compounds. Preferred co-matrix materials are therefore selected from the group of hole-transporting compounds, preferably carbazole, indenocarbazole, indolocarbazole or triarylamine derivatives. Another object of the invention is therefore a mixture containing at least one compound of formula (1) or at least 20 a corresponding preferred compound and at least one further compound selected from the group consisting of matrix materials, phosphorescent emitters, fluorescent emitters and/or emitters exhibiting TADF (thermally activated delayed fluorescence). Suitable matrix materials and emitters that can be used in this mixture according to the invention are described below. Particularly suitable hole-transporting matrix materials, which are advantageously combined with compounds of formula (1) as previously described or preferably described, in a mixed-matrix system, 30 can be selected from the compounds of formulas (HH-1), (HH-2), (HH-3), (HH-4), (HH-5), (HH-6), (HH-7) or (HH-8) described below. Another object of the invention is accordingly an organic 35 electronic device comprising an anode, a cathode and Foreignfiling_text P24-134.doc - 33 - 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 according to the invention as the first matrix material and at least one compound according to one of formulas (HH-1), (HH-2), (HH-3), (HH-4), (HH-5), (HH-6) or (HH-7) as the second matrix material 5, 10 Formula (HH-1) Ar 5 [R 6 ] t [R 6 ] N u 15 1 [R 6 ] t A 6 [R 6 ] s [R ] s N Ar 5 Formula (HH-2) 20 25 Formula (HH-3) 30 Formula (HH-4) 35 Foreignfiling_text P24-134.doc - 34 - 5 Formula (HH-5) 10 Formula (HH-6) Ar 5 NR 6 t R 6 s 15 NR 6 s R 6 s Formula (HH-7) where the following applies to the symbols and indices used: 20 A 1 is C(R 7 )2, NR 7 , O or S; L is a bond, O, S, C(R 7 )2 or NR 7 ; A is, independently of each occurrence, a group of formula (HH-4-1) or (HH-4-2), 25 30 Formula (HH-4-1) Formula (HH-4-2); X2 is, in each occurrence, the same or different from CH, CR 6 or N, where a maximum of 2 symbols can represent X2 N; * denotes the bonding site to formula (HH-4); U1 , U2, when present, form a bond, O, S, C( R7 )2 or NR7 ; 35 Foreignfiling_text P24-134.doc - 35 - R 6 is, in each occurrence, the same or different D, F, CN, a straight-chain alkyl group with 1 to 20 C atoms, or an alkenyl or alkynyl group with 2 to 20 C atoms, or a branched or cyclic alkyl group with 3 to 20 C atoms, wherein the alkyl, alkenyl or alkynyl group may each be substituted with one or more R 7 residues, and wherein one or more non-adjacent CH2 groups may be replaced by Si(R 7 )2, C=O, NR 7 , O, S or CONR 7 , or an aromatic or heteroaromatic ring system with 5 to 60 ring atoms, each of which may be substituted by one or more R 7 residues; Two residues 10 R 6 can also form an aromatic, heteroaromatic, aliphatic or heteroaliphatic ring system together; Ar5, whether the same or different, independently represents an aromatic or heteroaromatic ring system with 5 to 40 ring atoms, which may be substituted with one or more residues R 7 ; R 7 is the same or different in each occurrence D, F, Cl, Br, I, N(R 8 )2, CN, NO2, OR 8 , SR 8 , Si(R 8 )3, B(OR 8 )2, C(=O)R 8 , P(=O)(R 8 )2, S(=O)R 8 , S(=O)2R 8 , OSO2R 8 , a straight-chain alkyl group with 1 to 20 C atoms or an alkenyl or alkynyl group with 2 to 20 C atoms or a branched or cyclic alkyl group with 3 to 20 C atoms, wherein the alkyl, alkenyl or alkynyl group may each be substituted with one or more R 8 substituents, wherein one or more non-adjacent CH2 groups are replaced by Si(R 8 )2, C=O, NR 8 , O, S or CONR 8 may be replaced, or an aromatic 25 or heteroaromatic ring system with 5 to 40 ring atoms, each of which may be substituted by one or more residues R 8 , wherein R 8 does not mean H; in this respect, two or more residues R 7 may together form an aromatic, heteroaromatic, aliphatic or heteroaliphatic ring system, preferably the 30 residues R 7 do not form such a ring system; R 8 is, in each occurrence, the same or different H, D, F or an aliphatic, aromatic or heteroaromatic organic residue, in particular a hydrocarbon residue, with 1 to 20 C atoms, in which one or more H atoms may also be replaced by D or F 35; Foreignfiling_text P24-134.doc - 36 - c, c1, c2 each independently mean 0 or 1 for each occurrence, where the sum of the indices for each occurrence c+c1+c2 = 1; d, d1, d2 each independently mean 0 or 1 for each occurrence, where the sum of the indices for each occurrence d+d1+d2 = 1; q, q1, q2 each independently mean 0, 1, 2, 3 or 4 for each occurrence; s is equal to or different from 0, 1, 2, 3 or 4 for each occurrence; t is equal to or different from 0, 1, 2, or 3 for each occurrence; u is equal to or different from 0, 1 or 2 for each occurrence; u1, u2 each independently mean 0 or 1 for each occurrence, where the sum u1 + u2 = 1; and v is 0, 1, 2, or 3. 15 Preferred compounds of formula (HH-5) are compounds of formulas (HH-5-A) to (HH-5-E), 20 Formula (HH-5-A) 25 30 Formula (HH-5-B) 35 Foreignfiling_text P24-134.doc - 37 - 5 Formula (HH-5-C) 10 Formula (HH-5-D) 15 Formula (HH-5-E) where Ar5, R6 , s, and u have a previously stated or preferably stated meaning. 20 Preferred compounds of formula (HH-7) are the compounds of the following formula (HH-7-A), 25 30 Formula (HH-7-A) where the symbols used have the meanings given above. 35 In compounds of formulas (HH-1), (HH-2), (HH-3), (HH-5), (HH-5-A), (HH-5-B), (HH-5-C), (HH-5-D), (HH-5-E), (HH-6), (HH-7), or (HH-7-A), Foreignfiling_text P24-134.doc - 38 - s is preferably 0 or 1 if the residue R 6 is different from D, and particularly preferably 0. In compounds of formulas (HH-1), (HH-2), (HH-3), (HH-7) or (HH-7-A), t is preferably 0 or 1 if the residue R 6 is different from D, and 5 is particularly preferably 0. In compounds of formulas (HH-1), (HH-2), (HH-3), (HH-5), (HH-5-A), (HH-5-B), (HH-5-C), (HH-5-D) or (HH-5-E), u is preferably 0 or 1 if the residue R 6 is different from D, or particularly preferably 0. 10 The sum of the indices s, t and u in compounds of formulas (HH-1), (HH-2), (HH-3), (HH-5), (HH-5-A), In (HH-5-B), (HH-5-C), (HH-5-D), (HH-5-E), (HH-6), (HH-7), or (HH-7-A), the value is preferably at most 6, more preferably at most 4, and most preferably at most 2. This is especially true if R6 is different from D. 15 In compounds of formula (HH-4), c, c1, and c2 each independently mean 0 or 1 at each occurrence, where the sum of the indices at each occurrence means c + c1 + c2. Preferably, c2 means 1. 20 In compounds of formula (HH-4), L is preferably a single bond or C( R7 )2, where R7 has a previously mentioned meaning; most preferably, L is a single bond. In formula (HH-4-1), v is preferably 0 or 1 if the residue R6 is different from D. 25 In formula (HH-4-2), U1 or U2, if present, is preferably a single bond or C( R7 )2, where R7 has a previously mentioned meaning; U1 or U2, if present, is particularly preferably a single bond. In formula (HH-4-2), q, q1, q2 are preferably 0 or 1 if the residue R6 30 is different from D. In a preferred embodiment of the compounds of formulas (HH-1), (HH-2), (HH-3), (HH-4), (HH-5), (HH-5-A), (HH-5-B), (HH-5-C), (HH-5-D), (HH-5-E), (HH-6), (HH-7) or (HH-7-A), which according to the invention 35 are combined with compounds of formula (1) or the preferred embodiments, Foreignfiling_text P24-134.doc - 39 - forms can be combined, R 6 is the same or different at each occurrence selected from the group consisting of D, F, CN, a straight-chain alkyl group with 1 to 20 C atoms or a branched or cyclic alkyl group with 3 to 20 C atoms, wherein the alkyl group may each be substituted with one or more R 7 substituents, or 5 an aromatic or heteroaromatic ring system with 5 to 60 ring atoms, preferably with 5 to 40 ring atoms, each of which may each be substituted by one or more R 7 substituents. In a preferred embodiment of the compounds of formulas 10 (HH-1), (HH-2), (HH-3), (HH-4), (HH-5), (HH-5-A), (HH-5-B), (HH-5-C), (HH-5-D), (HH-5-E), (HH-6), (HH-7) or (HH-7-A), which can be combined according to the invention with compounds of formula (1) or preferred compounds of formula (1) as previously described, R 6 is the same or different in each occurrence selected from the group 15 consisting of D or an aromatic or heteroaromatic ring system with 6 to 30 ring atoms, which may be substituted with one or more substituents R 7 . Ar5 is preferably selected in compounds of formulas (HH-1), (HH-2), (HH-3), (HH-5), (HH-5-A), (HH-5-B), (HH-5-C), (HH-5-D), (HH-5-E), (HH-6), (HH-7) or (HH-7-A) from phenyl, biphenyl, in particular ortho-, meta- or para-biphenyl, terphenyl, in particular ortho-, meta-, para- or branched terphenyl, quaterphenyl, in particular ortho-, meta-, para- or branched quaterphenyl, fluorenyl, which may be linked via the 1-, 2-, 3- or 4-position, 9,9-dimethylfluorenyl, which may be linked via the 1-, 2-, 3- or 4-position, spirobifluorenyl, which may be linked via the 1-, 2-, 3- or 4-position, naphthyl, in particular 1- or 2-linked naphthyl, or residues derived from indole, benzofuran, benzothiophene, carbazole, which may be linked via the 1-, 2-, 3-, 30- or 4-position, dibenzofuran, which may be linked via the 1-, 2-, 3- or 4-position, dibenzothiophene, which may be linked via the 1-, 2-, 3- or 4-position, indenocarbazole, indolocarbazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, isoquinoline, quinazoline, quinoxaline, phenanthrene or triphenylene, which 35 Foreignfiling_text P24-134.doc - 40 - each may be substituted with one or more R 7 groups. Preferably, Ar5 is deuterated, but not further substituted. If A 1 in formula (HH-2) or (HH-3) or (HH-6) represents NR 7 , the substituent R 7 bonded to the nitrogen atom preferably represents 5 an aromatic or heteroaromatic ring system with 5 to 24 ring atoms, which may also be substituted by one or more R 8 groups. In a particularly preferred embodiment, this substituent R 7 represents, in each instance, an aromatic or heteroaromatic ring system with 6 to 24 ring atoms, 10 particularly with 6 to 18 ring atoms. Preferred embodiments for R 7 are phenyl, biphenyl, terphenyl, and quaterphenyl, which are preferably deuterated, as well as groups derived from triazine, pyrimidine, and quinazoline, which may be substituted by one or more groups R 8 , where R 8 does not denote H. 15 If A 1 in formula (HH-2), (HH-3), or (HH-6) represents C(R 7 )2, the substituents R 7 bonded to this carbon atom preferably represent, or differ from, a linear alkyl group with 1 to 10 carbon atoms, or a branched or cyclic alkyl group with 3 to 10 carbon atoms, or an aromatic or heteroaromatic ring system with 5 to 24 ring atoms, which may also be substituted by one or more groups R 8 , where R 8 does not denote H. R7 is particularly favored to represent a methyl group or a phenyl group. The R7 residues can also form a ring system with each other, resulting in a spiro system. Other suitable hole-transporting host materials, especially for use in combination with blue phosphorescent emitters, are the structures of the following formula (HH-8): 30 R N1 XNR M1 XMXNR M2 X m 35 RN2 n Formula (HH-8) Foreignfiling_text P24-134.doc - 41 - where the following applies to the symbols and indices used: M is Si or Ge, preferably Si; X is, in each occurrence, the same or different CR or N, provided that no more than two X per cycle stand for N; RM1 , RM2 are, in each occurrence, the same or different, a straight-chain alkyl group with 1 to 20 C atoms, or a branched or cyclic alkyl group with 3 to 20 C atoms, in which one or more H atoms may be replaced by D or F, or an aromatic or heteroaromatic ring system with 5 to 40 aromatic ring atoms, which may be substituted with one of the several R groups, wherein R has the meanings mentioned above; RM1 and RM2 may also together form an aliphatic, aromatic, or heteroaromatic ring system; R N1 and R N2 , whether identical or different, are aromatic or heteroaromatic ring systems with 5 to 40 aromatic ring atoms, which may be substituted with one of several substituents R20, where R has the meanings mentioned above; n is 1 or 2; and m25 is (2 − n). In a preferred embodiment of the compounds of formulas (HH-1), (HH-2), (HH-3), (HH-4), (HH-5), (HH-5-A), (HH-5-B), (HH-5-C), (HH-5-D), (HH-5-E), (HH-6), (HH-7), (HH-7-A), and (HH-8), these 30 compounds are partially or completely deuterated, particularly preferably completely deuterated. The preparation of the compounds of formulas (HH-1), (HH-2), (HH-3), (HH-4), (HH-5), (HH-5-A), (HH-5-B), (HH-5-C), (HH-5-D), (HH-5-E), (HH-356), (HH-7), (HH-7-A) and (HH-8) is generally known, and some of the compounds are commercially available. Foreignfiling_text P24-134.doc - 42 - Compounds of formula (HH-4) are disclosed, for example, in WO2021/180614, pages 110 to 119, in particular as examples on pages 120 to 127. Their preparation is disclosed in WO2021/180614 A1 on page 128 and in the synthesis examples on pages 214 to 218. 5 The preparation of the triarylamines of formula (HH-6) is known to those skilled in the art, and some of the compounds are commercially available. If the at least one other matrix material is a deuterated compound, it is possible that a mixture of deuterated compounds with the same basic chemical structure may be obtained, differing only in the degree of deuteration and/or the deuteration pattern. 15 In a preferred embodiment of the at least one further matrix material, it is a mixture of deuterated compounds of formulas (HH-1), (HH-2), (HH-3), (HH-4), (HH-5), (HH-5-A), (HH-5-B), (HH-5-C), (HH-5-D), (HH-5-E), (HH-6), (HH-7), (HH-7-A) or (HH-8), as previously described, wherein the average degree of deuteration of these 20 compounds is at least 50 mol% to 90 mol%, preferably 70 mol% to 100 mol%. Examples of suitable further matrix materials for combination with compounds of formula (1), as previously described or preferably described in 25, are the compounds described in WO 2019/229011 A1, Table 3, pages 137 to 203, which may also be partially or completely deuterated. Examples of suitable further matrix materials for combination with 30 compounds of formula (1) or preferred compounds of formula (1), as previously or preferably described, are the compounds described in WO 2021/180625 A1, Table 3, pages 131 to 137 and in Table 4, pages 137 to 139, which may also be partially or completely deuterated. 35 Foreignfiling_text P24-134.doc - 43 - Examples of suitable further matrix materials for combination with compounds of formula (1) or preferred compounds of formula (1), as previously or preferably described, are the compounds described in KR 20230034896 A, on pages 42 to 47, compounds [2-1] to [2-110], or on pages 49 to 51, compounds [3-1] to [3-26]. Examples of suitable further matrix materials for combination with compounds of formula (1) or preferred compounds of formula (1), as previously or preferably described, are the compounds described in KR 20230154750 A, on pages 39 to 49, compounds [B-1] to [B-243], or on pages 49 to 53, compounds [C-1] to [C-102], or on pages 54 to 57, compounds [D-1] to [D-120]. 15 Examples of suitable additional matrix materials for combination with compounds of formula (1) or preferred compounds of formula (1), as previously or preferably described, are the compounds described in US 2023/0172065 A, on pages 413 to 434. 20 Further examples of suitable host materials of formulas (HH-1), (HH-2), (HH-3), (HH-4), (HH-5), (HH-5-A), (HH-5-B), (HH-5-C), (HH-5-D), (HH-5-E), and (HH-6) for combination with compounds of formula (1) or preferred compounds of formula (1), as previously or preferably described, are the structures listed below in Table 2 and Table 3. Table 2: 30 35

 Foreignfiling_text P24-134.doc - 48 - 5 10 15 NN 20 NN n ⁿ 25 30 35 Foreignfiling_text P24-134.doc - 49 - NNN 5 N nn 10 NN n 15 20 25 30 35 Foreignfiling_text P24-134.doc - 50 - NN 5 n 10 15 20 25 30 NN 35 _n Foreignfiling_text P24-134.doc - 51 - NNN 5 n 10 15 NN 20 N n 25 30 35 Foreignfiling_text P24-134.doc - 52 - 5 10 15 ON 20 N n 25 30 35

30

35 



-09- Foreignfiling_text P24-134.doc - 61 - 5 10 15 20 25 In the table above, n represents the number of D atoms in the respective compound and is 0 or D1 to Dmax, preferably D1 to Dmax. If n = 0, this means that it is a non-deuterated compound. n = D1 means that in the respective compound, one H atom is replaced by one D atom. Dmax means the maximum number of D atoms possible in the respective compound. The maximum number Dmax can vary from compound to compound. Foreignfiling_text P24-134.doc - 62 - vary. Dmax can assume the following values depending on the compound: 20, 24, 26, 28, 30, 31, 32, 34, 35, 36, 37, 38 and 40. Particularly suitable compounds of formulas (HH-1), (HH-2), (HH-3), (HH-4), (HH-5), (HH-5-A), (HH-5-B), (HH-5-C), (HH-5-D), (HH-5-E) or (HH-6), 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 compounds of Table 3. 10 Table 3: 15 20 H1 H2 H3 25 30 H4 H5 H6 35 Foreignfiling_text P24-134.doc - 63 - 5 H7 H8 H9 10 15 20 H10 H11 H12 25 30 H13 H14 H15 35 Foreignfiling_text P24-134.doc - 64 - 5 H16 H17 H18 10 15 H19 H20 H21 20 25 30 H22 H23 H24 35 Foreignfiling_text P24-134.doc - 65 - 5 10 H25 H26 H27 15 20 H28 H29 H30 25 30 H31 H32 H33 35 Foreignfiling_text P24-134.doc - 66 - 5 H34 H35 H36 10 15 H37 H38 H39 20 25 H40 H41 H42 30 35 Foreignfiling_text P24-134.doc - 67 - 5 H43 H44 H45 10 15 H46 H47 H48 20 25 H49 H50 H51 Examples of host materials of formula (HH-7) or (HH-7-A), which are particularly suitable for use in combination with blue phosphorescent emitters, are the structures shown in the following Table 4: Table 4: 35 Foreignfiling_text P24-134.doc - 68 - 5 10 15 20 25 The aforementioned host materials of formula (1) and their preferably described embodiments can be combined in the device according to the invention as desired with the aforementioned matrix materials, the matrix materials of formulas (HH-1), (HH-2), (HH-3), (HH-4), (HH-5), (HH-5-A), (HH-5-B), (HH-5-C), (HH-5-D), (HH-5-E), (HH-6), (HH-7), (HH-7-30 A) or (HH-8) and their preferably described embodiments in Table 2, 3 or 4. The concentration of the host material of formula (1), as previously described or preferably described, in the mixture 35 according to the invention or in the light-emitting layer of the device according to the invention Foreignfiling_text P24-134.doc - 69 - is usually in the range of 5 wt.% to 90 wt.%, preferably in the range of 10 wt.% to 85 wt.%, more preferably in the range of 20 wt.% to 85 wt.%, even more preferably in the range of 30 wt.% to 80 wt.%, most preferably in the range of 20 wt.% to 60 wt.% and most preferably in the range of 30 wt.% to 550 wt.%, based on the entire mixture or based on the entire composition of the light-emitting layer. The concentration of the sum of all host materials of formulas (HH-1), (HH-2), (HH-3), (HH-4), (HH-5), (HH-5-A), (HH-5-B), (HH-5-C), (HH-5-D), (HH-5-E), (HH-6), (HH-7), (HH-7-A) or (HH-8), as previously described or preferably described, in the mixture according to the invention or in the light-emitting layer of the device according to the invention is typically in the range of 10 wt.% to 95 wt.%, preferably in the range of 15 wt.% to 90 wt.%, more preferably in the range of 15 wt.% to 80 wt.%, even more preferably in the range of 20 wt.% to 70 wt.%, most preferably in the range of 40 wt.% to 80 wt.% and most preferably in the range of 50 wt.% to 70 wt.%, based on the entire mixture or based on the entire composition of the light-emitting Layer. 20 The present invention also relates to a mixture which, in addition to the host materials of formula (1) mentioned above, hereinafter referred to as host material 1, and the host material of at least one of the formulas (HH-1), (HH-2), (HH-3), (HH-4), (HH-5), (HH-5-A), (HH-5-B), (HH-5-C), 25 (HH-5-D), (HH-5-E), (HH-6), (HH-7), (HH-7-A) and (HH-8), hereinafter referred to as host material 2, as previously described or preferably described, contains at least one phosphorescent emitter. The term phosphorescent emitters typically encompasses compounds in which light emission occurs through a spin-forbidden transition from an excited state with a 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, a transition from a triplet state is understood here. Foreignfiling_text P24-134.doc - 70 - Phosphorescent emitters (= triplet emitters) are particularly suitable compounds which, upon suitable excitation, emit light, preferably in the visible range, and which 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, especially a metal with this atomic number. Compounds containing copper, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, iridium, palladium, platinum, silver, gold, or europium are preferably used as phosphorescent emitters, especially compounds containing iridium or platinum. For the purposes of the present invention, all luminescent compounds containing the aforementioned metals are considered phosphorescent emitters. In general, all phosphorescent complexes are suitable, such as those used in phosphorescent OLEDs according to the prior art 15 and as are known to the skilled person in the field of organic electroluminescence devices. Examples can be found in applications WO 00/70655, WO 2001/41512, WO 2002/02714, WO 2002/15645, EP 1191613, EP 1191612, EP 1191614, WO 2005/033244, WO 2005/019373, US 2005/0258742, WO 2009/146770, WO 2010/015307, WO 2010/031485, WO 2010/054731, WO 2010/054728, WO 2010/086089, WO 2010/099852, WO 2010/102709, WO 2011/032626, WO 2011/066898, WO 2011/157339, WO 2012/007086, WO 2014/008982, WO 2014/023377, WO 2014/094961, WO 2014/094960, WO 2015/036074, WO 2015/104045, WO 25 2015/117718, WO 2016/015815, WO 2016/124304, WO 2017/032439, WO 2018/011186 and WO 2018/041769, WO 2019/020538, WO 2018/178001, WO 2019/115423 and WO 2019/158453. 30 Preferred phosphorescent emitters correspond to the following formula (I), 35 Foreignfiling_text P24-134.doc - 71 - 5 Formula (I) where the symbols and indices for this formula (I) have the following meanings: 10 n+m is 3, n is 1 or 2, m is 2 or 1, X is the same or different N or CR in each occurrence, R is the same or different H, D, F, CN or a branched or linear alkyl group with 1 to 10 C atoms or a partially or completely deuterated branched or linear alkyl group with 15 1 to 10 C atoms or a cycloalkyl group with 4 to 7 C atoms, which may be partially or completely substituted with deuterium or an aromatic or heteroaromatic ring system with 5 to 60 ring atoms, which may be partially or completely substituted with deuterium. 20 In emitters of formula (I), n is preferably 1 and m is preferably 2. In emitters of formula (I), one X is preferably selected from N and the other X denote CR, or all X represent CR, either the same or different, in each occurrence. 25 In emitters of formula (I), at least one R is preferably different from H. In emitters of formula (I), two R are preferably different from H and have one of the meanings previously given. 30 Platinum complexes of the following formula (II) are also preferred. 35 Foreignfiling_text P24-134.doc - 72 - 5 Formula (II) where R has the meaning given above and furthermore: 10 Y 1 , Y 2 , Y 3 , Y 4 , Y 5 , in each occurrence, stand for a group CR Y or N, either the same or different; or Y 1 -Y 2 and/or Y 3 -Y 4 or Y 4 -Y 5 can form a fused aryl or heteroaryl ring with 5 to 18 aromatic ring atoms, each of which can also be substituted by one or more R groups; E 50, in each occurrence, stands for C(R C0 )2, NR N0 , O or S, either the same or different; 20 Ar 50 , in each occurrence, is an aromatic or heteroaromatic ring system with 5 to 40 aromatic ring atoms, each of which can also be substituted by one or more R groups; 25 Ar 51 , Ar 52 , Ar 53 , whether the same or different, represent a fused aryl or heteroaryl ring with 5 to 18 aromatic ring atoms, each of which may also be substituted by one or more R groups; 30 R Y, in each occurrence the same or different, represents a group selected from H, D, F, Cl, Br, I, CHO, CN, C(=O)R, P(=O)(R)2, S(=O)R, S(=O)2Ar, N(R)2, NO2, Si(R)3, B(OR)2, OSO2R, a straight-chain alkyl, alkoxy or thioalkyl group with 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkyl group with 35 to 40 C atoms, each of which may be substituted by one or more R groups Foreignfiling_text P24-134.doc - 73 - can be substituted, wherein one or more non-adjacent CH2 groups can be replaced by RC=CR, C≡C, Si(R)2, Ge(R)2, Sn(R)2, C=O, C=S, C=Se, P(=O)(R), SO, SO2, O, S or CONR and wherein one or more H atoms can be replaced by D, F, Cl, Br, I, CN or NO2, an aromatic or 5 heteroaromatic ring system with 5 to 40 aromatic ring atoms, each of which can be substituted by one or more R groups, and an aryloxy group with 5 to 40 aromatic ring atoms, which can be substituted by one or more R groups, wherein two R Y groups together form an aliphatic, aromatic 10 or heteroaromatic ring system, which can be substituted by one or more R' residues can be substituted; R C0, in each occurrence the same or different, represents a residue selected from H, D, a straight-chain alkyl group with 1 to 40 C-15 atoms, which can be substituted by one or more residues R, an aryl or heteroaryl group with 6 to 18 aromatic ring atoms, each of which can be substituted by one or more residues R, wherein two residues R C together can form an aliphatic, aromatic or heteroaromatic ring system substituted by one or more residues R; R N0, in each occurrence, is the same or different for a residue selected from H, D, F, a straight-chain alkyl group with 1 to 40 C atoms or a branched or cyclic alkyl group with 3 to 25 C atoms, each of which is substituted by one or more residues R, wherein one or more H atoms may be replaced by D, F or CN, or an aromatic or heteroaromatic ring system with 5 to 40 aromatic ring atoms, each of which may be substituted by one or more residues R. 30 Preferably, Ar 50, in each occurrence, is the same or different for an aromatic or heteroaromatic ring system with 5 to 30, particularly preferably 6 to 24 and most preferably 6 to 18 aromatic ring atoms, each of which may also be substituted by one or more residues R. Foreignfiling_text P24-134.doc - 74 - Preferably Ar 51 , Ar 52 , Ar 53 represent, equally or differently, a condensed aryl or heteroaryl ring with 6 aromatic ring atoms, each of which may also be substituted by one or more R groups. 5 Preferably, R Y, in each occurrence, represents H, D, F, a straight-chain alkyl, alkoxy, or thioalkyl group with 1 to 40, preferably 1 to 20, and more preferably 1 to 10 C atoms, or a branched or cyclic alkyl, alkoxy, or thioalkyl group with 3 to 40, preferably 3 to 20, and more preferably 3 to 10 C atoms, each of which may be substituted by one or more R groups, wherein one or more non-adjacent CH2 groups may be replaced by RC=CR, C≡C, O, or S, and wherein one or more H atoms may be replaced by D or F, an aromatic or heteroaromatic ring system with 5 to 30, particularly preferably 5 to 18 aromatic ring atoms, each of which may be substituted by one or more R groups. Preferably, R C0 , in each occurrence, represents a residue selected from H, D, a straight-chain alkyl group with 1 to 20, preferably 1 to 6, and more preferably 1 to 3 carbon atoms, which may be substituted by one or more residues R, an aryl or heteroaryl group with 6 to 18, and preferably 6 to 12, aromatic ring atoms, each of which may be substituted by one or more residues R, wherein two residues RC0 together may form an aliphatic, aromatic, or heteroaromatic ring system substituted by one or more residues R. Preferably, R N0 , in each occurrence, represents a residue selected from an aromatic or heteroaromatic ring system with 5 to 40, particularly preferably 5 to 30, and even more preferably 5 to 18, aromatic ring atoms, each of which may be substituted by one or more residues R. Another object of the invention is therefore an organic 35 electroluminescent device, as previously described or previously- Foreignfiling_text P24-134.doc - 75 - described, characterized in that the light-emitting layer contains, in addition to the host material(s), at least one phosphorescent emitter corresponding to one of formulas (I) or (II). Preferred examples of phosphorescent emitters are described in WO 5 2019/007867 on pages 120 to 126 in Table 5 and on pages 127 to 129 in Table 6. The emitters are included in the description by reference. Particularly preferred examples of phosphorescent emitters are listed in the following Table 5. 10 Table 5: NO NO 15 Ir Ir OO 2 F 2 20 NN NNN Pt NN Ir Pt 3 25 CD 3 CD NN 3 Ir N N NN Ir Ir N 30 3 2 3 35 Foreignfiling_text P24-134.doc - 76 - 5 10 15 20 25 DD DD DDD D C D 3 CD3 D D NN Ir DDNN CD 3 O Ir 30 NDDOND 2 CD DDD 3 2 35 Foreignfiling_text P24-134.doc - 77 - 5 10 15 N Ir NN 20 ONC D 2 3 DDDNDN Ir 25 DNDD D 30 35 Foreignfiling_text P24-134.doc - 78 - 5 10 Examples of suitable blue phosphorescent platinum and iridium complexes are shown in Table 6 below: 15 Table 6: 20 25 30 35 Foreignfiling_text P24-134.doc - 79 - F F Pt N DN N N DDDDD 5 DDDD 2 417635-93-7 10 15 20 25 30 35 Foreignfiling_text P24-134.doc - 82 - ON Pt NNNNNDDDD D DD 5 DDD 10 15 20 25 30 35 Foreignfiling_text P24-134.doc - 83 - In a further preferred embodiment of the invention, the at least one light-emitting layer of the organic electroluminescent device can have three or four different matrix materials, preferably three different matrix materials. These corresponding mixed-matrix systems can consist of the matrix materials described for host material 1 and host material 2, but they can also include, for example, wide-band-gap materials, bipolar host materials, electron transport materials (ETMs), or hole transport materials (HTMs) as a third or fourth matrix material, in addition to host material 1 or host material 2. According to one embodiment of the present invention, the mixture contains no further components, i.e., functional materials, in addition to the components of host material 1 and host material 2 as previously or preferably described. These are material mixtures that are 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 deposition of the host materials for the light-emitting layer and which have a constant mixing ratio during deposition. This allows for the simple and rapid deposition of a layer with a uniform distribution of components, without the need for precise control of a multitude of material sources. According to an alternative embodiment of the present invention, the mixture contains, in addition to the components of host material 1 and host material 2 as previously or preferably described, a phosphorescent emitter as previously described. With a suitable mixing ratio during deposition, this mixture can also be used as the sole material source. Preferred are premix systems consisting of two matrix materials, namely a compound of formula (1) and a compound of one of the formulas (HH-1), (HH-2), (HH-3), (HH-4), (HH-5), (HH-5-A), (HH-5-B), (HH-355-C), (HH-5-D), (HH-5-E), (HH-6), (HH-7), (HH-7-A) or (HH-8). Foreignfiling_text P24-134.doc - 84 - Premix systems consisting of three matrix materials are still preferred, namely one combination of formulas (1) and two combinations of one of the formulas (HH-1), (HH-2), (HH-3), (HH-4), (HH-5), (HH-5-A), (HH-5-B), (HH-5-C), (HH-5-D), (HH-5-E), (HH-6), (HH-7), (HH-7-A) or (HH-8). 5 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.%, and most preferably between 97 and 80 vol.% of matrix material consisting of at least one compound according to the invention and at least one compound of one of the formulas (HH-1), (HH-2), (HH-3), (HH-4), (HH-5), (HH-5-A), (HH-5-B), (HH-5-C), (HH-5-D), (HH-5-E), (HH-6), (HH-7), (HH-7-A) or (HH-8) 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.%, and most preferably between 20.3 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.% specified above. Fluorescent emitters may also be contained in the light-emitting layer of the device according to the invention or in the mixture according to the invention. Preferred fluorescent emitting compounds are selected from the class of arylamines, wherein preferably at least one of the aromatic or heteroaromatic ring systems of the arylamine is a condensed ring system, particularly preferably with at least 14 ring atoms. Preferred examples include aromatic anthracene amines, aromatic anthracenediamines, aromatic pyrene amines, aromatic pyrenediamines, aromatic chrysene amines, or aromatic chrysenediamines. An aromatic anthracene Foreignfiling_text P24-134.doc - 85 - is understood to be a compound in which a diarylamine group is directly bonded to an anthracene group, preferably at the 9 position. An aromatic anthracene diamine is understood to be a compound in which two diarylamine groups are directly bonded to an anthracene group, preferably at the 9, 10 position. Aromatic pyrenamines, pyren-5 diamines, chrysenamines, and chrysendiamines are defined analogously, wherein the diarylamine groups on the pyrene are preferably bonded at the 1 position or at the 1, 6 position, respectively. Other preferred emitting compounds are indenofluorenamines or diamines, benzoindenofluorenamines or diamines, and dibenzoindenofluorenamines or diamines, 10 as well as indenofluorene derivatives with fused aryl groups. Pyrene arylamines are also preferred. Benzoindenofluorene amines, benzofluorene amines, extended benzoindenofluorenes, phenoxazines, and fluorene derivatives linked to furan or thiophene units are also preferred. Furthermore, the light-emitting device 15 or the mixture according to the invention may also contain materials exhibiting TADF (thermally activated delayed fluorescence). In a preferred embodiment of the invention, the fluorescent emitter is selected from structures of the following formula (F-1), 20 Ar 30 Y 31 Y32 Y 30 A r 31 Ar 32 25 Y 33 q formula (F-1) where R has the meanings mentioned above and for the other symbols and indices used: 30 Ar 30 , Ar 31 , Ar 32 is, whether the same or different, a substituted or unsubstituted aromatic or heteroaromatic ring system with 5 to 30 aromatic ring atoms; 35 Y 30 is B or N; Foreignfiling_text P24-134.doc - 86 - Y 31 , Y 32 , Y 33 is the same or different at each occurrence and stands for O, S, C(R 0 )2, C=O, C=S, C=NR 0 , C=C(R 0 )2, Si(R 0 )2, BR 0 , NR 0 , PR 0 , SO2, SeO2 or a chemical bond, with the proviso that if Y 30 stands for B, at least one of the groups Y 31 , Y 32 , Y 33 stands for 5 NR 0 , and if Y 30 stands for N, at least one of the groups Y 31 , Y 32 , Y 33 stands for BR 0 ; R 0 is the same or different in each occurrence, H, D, F, a straight-chain alkyl group with 1 to 20, preferably with 1 to 10 C atoms or 10 a branched or cyclic alkyl group with 3 to 20, preferably with 3 to 10 C atoms, each of which may be substituted with one or more substituents R, wherein one or more non-adjacent CH2 groups may be replaced by O or S and wherein one or more H atoms may be replaced by D or F, 15 or an aromatic or heteroaromatic ring system with 5 to 40, preferably with 5 to 30, particularly preferably with 6 to 18 aromatic ring atoms, each of which may be substituted with one or more substituents R; Two adjacent substituents R 0  can form an aliphatic or aromatic ring system, which may be substituted with one or more substituents R0; q is 0 or 1. Particularly preferred are compounds where: - q = 0; Y 30 = B; and Y 31 , Y 32 = NR 0 ; or - q = 0; Y 30 = B; and Y 31 , Y 32 = NR 0 ; or - q = 1; Y 30 = N; and Y 31 , Y 32 = BR 0 ; Y 33 = chemical bond. Examples of suitable fluorescent emitters are shown in the table below. Foreignfiling_text P24-134.doc - 91 - 5 10 BO O N 15 NN 20 25 30 35 Foreignfiling_text P24-134.doc - 92 - 5 10 The present invention also relates to an organic electroluminescent device as previously or preferably described, wherein the organic layer comprises a hole injection layer (HIL) and/or a hole transport layer (HTL), the hole-injecting material and hole-transporting material of which belong to the class of arylamines. 15 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 / hole-blocking layer / electron transport layer / electron injection layer / 20 cathode. This sequence of layers is a preferred sequence, but not all of the aforementioned layers need to be present and/or additional layers may be present. All materials 25 used as electron transport materials in the electron transport layer according to the prior art can be used as materials for the electron transport layer. Particularly suitable are aluminum complexes, for example Alq3, zirconium complexes, for example Zrq4, benzimidazole derivatives, triazine derivatives, pyrimidine derivatives, pyridine derivatives, pyrazine derivatives, quinoxaline derivatives, quinoline derivatives, oxadiazole derivatives, aromatic ketones, lactams, boranes, diazaphosphole derivatives, and phosphine oxide derivatives. In the further layers of the organic electroluminescence device according to the invention, all materials can be used as are commonly employed according to the prior art. The person skilled in the art can therefore, without inventive effort, use all materials suitable for organic electroluminescence. Foreignfiling_text P24-134.doc - 93 - Electroluminescent devices using known materials in combination with the compounds according to the invention. A further preferred option is an organic electroluminescent device characterized in that one or more layers are coated using a sublimation process. In this process, the materials are 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. A preferred option is also an organic electroluminescent device characterized in that one or more layers are coated using the OVPD (Organic Vapor Phase Deposition) process or with the aid of carrier gas sublimation. In this process, 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. 20 A further preferred organic electroluminescent device is characterized in that one or more layers are produced from solution, e.g., by spin coating, or by any printing process, e.g., screen printing, flexographic printing, offset printing, LITI (Light Induced Thermal Imaging, thermal transfer printing), inkjet printing, or 25 nozzle printing. Soluble compounds are required for this purpose, which can be obtained, for example, by suitable substitution. Hybrid processes are also possible, in which, for example, 30 or more layers of solution are applied and one or more further layers are vapor-deposited. When producing the device by means of vapor deposition, there are basically two possibilities for depositing the organic 35 layer according to the invention, preferably the light-emitting layer, onto any substrate. Foreignfiling_text P24-134.doc - 94 - substrate or the previous layer can be applied or evaporated. On the one hand, the materials used can each be placed in a separate material source and then evaporated from the different material sources ("co-evaporation"). On the other hand, the different materials can be premixed ("premixed", premix systems) and the mixture placed in a single material source from which it is then evaporated ("premix-evaporation"). This allows the evaporation of the light-emitting layer with a uniform distribution of the components to be achieved in a simple and fast manner, without the need for precise control of a large number of material sources. These methods are generally known to those skilled in the art and can be applied by them without inventive effort to electronic devices, in particular organic electroluminescent devices containing the compounds according to formula (1) according to the invention. All features of the present invention can be combined with one another in any way, unless certain features and/or steps are mutually exclusive. This applies in particular to preferred features of the present invention. Likewise, features of non-essential combinations can be used separately (and not in combination). The compounds and electronic devices according to the invention, in particular the organic electroluminescent devices, are characterized by one or more of the following surprising advantages over the prior art: 1. The materials according to the invention have a low refractive index. OLEDs containing these compounds as electron transport material in an electron transport layer and/or hole-blocking layer thereby exhibit improved light extraction, which leads to improved external quantum efficiency (EQE) of the OLED. Foreignfiling_text P24-134.doc - 95 - 2. The use of the compounds according to the invention as a matrix material for phosphorescent emitters or hyperphosphorescent emission layers leads to OLEDs with improved color purity by suppressing the formation of exciplexes (LUMO of the compound according to the invention and HOMO of the phosphorescent emitter or sensitizer). This also prevents a loss of efficiency. 3. OLEDs containing the compounds according to the invention as a matrix material for phosphorescent emitters or hyperphosphorescent emission layers result in long lifetimes, high efficiencies, and low operating voltages. The invention is further explained by the following examples without being intended to limit it. The person skilled in the art can implement the invention in its entire disclosed scope from the descriptions and produce further electronic devices according to the invention without inventive effort. Examples: Unless otherwise specified, the following syntheses are carried out under a protective gas atmosphere in dried solvents. The solvents and reagents can be obtained, for example, from Sigma-Aldrich or ABCR. The information in square brackets and the 25 numbers given for individual compounds refer to the CAS numbers of the compounds known from the literature. For compounds that can have several isomeric, enantiomeric, diastereomeric, or tautomeric forms, one form is shown as a representative example. 30 A: Synthons known from the literature LS*: 1) 1,3,5,7,9,11,14-Heptakis(alkyl/aryl)tricyclo[7.3.3.1 5,11 ]heptasiloxane- 3,7,14-triol 35 Foreignfiling_text P24-134.doc - 96 - 5 Rest R` CAS Synthon 326621-23-2 LS*1 10 Methyl 326621-07-2 LS*2 Ethyl 1046051-91-5 LS*3 15 n-Propyl 2800920-41-4 LS*4 iso-Propyl CH 3 20 CH 3 307531-92-6 LS*5 2-Methyl-propyl 183387-28-2 LS*6 Cyclopentyl 25 47904-22-3 LS*7 Cyclohexyl 444315-26-8 LS*8 30 Phenyl 2) Aryl-trialkoxy-silane 35 Foreignfiling_text P24-134.doc - 97 - NI Br OO Si S OO O i O 5 18036-94-7 81095-62-7 18954-74-0 18052-81-8 LS101 LS102 LS100 LS103 Alternatively, the trimethoxysilanes or trichlorosilanes known from the literature 10 can be used. B: Preparation of the synthons S: Example S1a: 15 20 Preparation by “corner capping reaction” according to I. Blanco et al., Journal of Thermal Analysis and Calorimetry (2012), 108(2), 807. Starting material: 4.97 g (10.0 mmol) LS*1 and 3.32 g (10.4 mmol) LS100. Yield: 5.85 g (8.6 mmol); 86 %; Purity: 98% n.l.H NMR. 25 The symbol “LS” in the symbolic representations of the following synthons S and examples B refers to the respective literature-known synthons LS*, which reacted with the aryl-triethoxysilanes via a condensation reaction and elimination of three equivalents of ethanol. Accordingly, the symbol “LS” in the symbolic representation 30 has three fewer hydrogen atoms, namely those of the three OH groups, than the LS* in the literature-known synthon. The following compounds can be represented analogously: Example: Reactants Product 35 Foreignfiling_text P24-134.doc - 98 - LS*2 S2a LS100 5 LS*3 S3a LS100 LS*4 S4a LS100 10 LS*5 S5a LS100 15 LS*6 S6a LS100 O LS*7 O S7a Si 20 LS100 LS7 Br O LS*8 S8a LS100 25 LS*1 S1b LS101 30 LS*2 S2b LS101 LS*3 S3b LS101 35 Foreignfiling_text P24-134.doc - 99 - LS*4 S4b LS101 5 LS*5 S5b LS101 LS*6 S6b LS101 10 LS*7 S7b LS101 15 LS*8 S8b LS101 LS*1 20 S1c LS102 LS*2 S2c LS102 25 LS*3 S3c LS102 30 LS*4 S4c LS104 35 Foreignfiling_text P24-134.doc - 100 - LS*5 S5c LS102 5 LS*6 S6c LS102 10 LS*7 S7c LS102 LS*8 15 S8c LS102 LS*1 S1d 20 LS103 Example S101a: 25 30 A well stirred mixture of 6.78 g (10.0 mmol) S1a, 5.08 g (20.0 mmol) Bis(pinacolato)diborane [73183-34-3], 2.95 g (30.0 mmol) Potassium acetate, anhydrous [127-08-2], 30 g glass beads (3 mm diameter), 222 mg (0.3 mmol) Bis(tricyclohexylphosphino)palladium(II) chloride [29934-17-6] and 100 ml of dioxane are stirred for 18 h at 100 °C. The mixture is then filtered while still warm through a Celite bed pre-flourished with dioxane. Foreignfiling_text P24-134.doc - 101 - The filtrate is concentrated under vacuum, the residue is dissolved in 200 ml of DCM, the organic phase is washed twice with 50 ml of water and once with 50 ml of saturated saline solution, and dried over magnesium sulfate. The filtrate is filtered through a silica gel bed pre-flourished with DCM, concentrated to dryness, and the oil is crystallized by adding 30 ml of tetrahydro-5-furan (THF) and 30 ml of acetonitrile. The filtrate is filtered and dried under vacuum. Yield: 5.92 g (8.2 mmol); 82%; Purity: approx. 98% by 1H-NMR. The following connections can be represented analogously: 10 Example: Reactant Product S102a S2a 15 S103a S3a S104a S4a 20 S105a S5a 25 S106a S6a S107a S7a 30 S108a S8a 35 Foreignfiling_text P24-134.doc - 102 - S101b S1b 5 S102b S2b 10 S103b S3b S104b S4b 15 S105b S5b 20 S106b S6b 25 S107b S7b 30 S108b S8b 35 Foreignfiling_text P24-134.doc - 103 - LS 1 S101c S1c 5 L S 2 S102c S2c 10 S103c S3c 15 L S 4 O OO Si S104c S4c O BO 20 S105c S5c 25 LS 6 O OO Si S106c S6c O BO 30 35 Foreignfiling_text P24-134.doc - 104 - LS 7 O OO Si S107c S7c O BO 5 L S 8 S108c S8c 10 S101d S1d 15 Example B1: 20 25 A well stirred mixture of 7.25 g (10.0 mmol) S101a, 2.68 g (10.0 mmol) 2-chloro-4,6-diphenyl-1,3,5-triazine [3842-55-5], tripotassium phosphate monohydrate [27176-10-9], 231 mg (0.2 mmol) tetrakis-triphenyl-30 phosphinopalladium(0), 30 g glass beads (3 mm diameter) and 120 ml DMSO is stirred for 24 h at 100 °C. After complete conversion, allow to cool, pour the reaction mixture into 200 ml of a water/methanol mixture (1:1 vv), stir briefly, filter off the precipitated solid, wash it three times with 50 ml of a water/methanol mixture 35 (1:1 vv) and five times with 30 ml of methanol, and dry under vacuum. Foreignfiling_text P24-134.doc - 105 - The solid is taken up in 300 ml of dichloromethane (DCM), filtered through a silica gel bed pre-flourished with DCM, and the filtrate is concentrated under vacuum at 40 °C with stirring, with the distilled-off DCM being substituted with methanol. The crystallized solid is filtered off, washed three times with 30 ml of methanol each time, and dried under vacuum. Further purification is carried out by repeated hot extraction crystallization (common organic solvents or combinations thereof, preferably acetonitrile-DCM, 1:3 to 3:1 vv) or chromatography and fractional sublimation or annealing under high vacuum. Yield: 5.49 g (6.6 mmol); 66%. Purity: 99.9% n. HPLC. 10 Alternatively, analogous to MF Roll, ACS Nano, 2008, 2, 2, 320, silver(I) oxide in THF can be used as a base. The following compounds can be prepared analogously. 15 Example: Starting material Product S101a Cl NNN B2 N 20 1268244-56-9 S101b Cl 25 NNN B3 N 1268244-56-9 30 S101c Cl NNN B4 N 35 1268244-56-9 Foreignfiling_text P24-134.doc - 106 - S102a Cl NNN B5 N 5 2 361416-42-2 S101a Cl NNN 10 B6 1472062-94-4 S101b 15 Cl NNN B7 20 1472062-94-4 S101c Cl NNN 25 B8 1472062-94-4 S102b 30 Cl NN B9 N N 35 Foreignfiling_text P24-134.doc - 107 - 2260688-83-1 S106a Cl NNN B10 5 O 2 142681-84-1 S104c Cl 10 NNNN B11 15 2260688-93-3 S101a Cl NN 20 B12 N 1689576-03-1 S101b Cl 25 NN N N B13 O 30 2260688-95-5 B14 S102c 35 Foreignfiling_text P24-134.doc - 108 - Cl NNNO 5 1472729-25-1 S101b Cl NNN 10 B15 182918-13-4 S101b 15 Cl NN N N B16 20 2260688-92-2 S101c Cl N B17 N N 25 N 2447065-52- S101b Cl 30 NNN B18 NN C 2570228-27-0 35 Foreignfiling_text P24-134.doc - 109 - S101b Cl N N NN B19 5 2567920-24-3 S107b Cl NN B20 N 10 O 1883265-32-4 S104a Cl 15 NN B21 N 3842-55-5 20 S107a SN B22 N Cl N 25 1476735-48-4 S108c Cl NNN 30 B23 1621467-35-3 35 Foreignfiling_text P24-134.doc - 110 - S101b N Cl N B24 NN 5 2172944-00-0 S101b DDD Cl 10 DN B25 NNDNDDD 2574571-56-3 15 S101c D D Cl NNDNND B26 DDDD 20 DD 1300115-09-6 S101b Cl NN B27 N 25 N 2173555-83-2 S101b O 30 B28 NN Cl N 35 2226747-67-5 Foreignfiling_text P24-134.doc - 111 - S108b Cl NF N B29 N 5 2098852-73-2 S101a Cl NN 10 B30 N N N 877615-05-9 S101b Cl 15 NN B31 N N N 877615-05-9 20 S101c Cl NN B32 N N N 25 8 77615-05-9 S101a Cl N B33 N N 30 N 1476785-42-8 35 Foreignfiling_text P24-134.doc - 112 - S101b Cl N NC N B34 N 5 2054155-13-2 S101b Cl NNN 10 B35 N 2348384-34-7 S101b 15 O Cl B36 NNN 20 2305720-32-3 S101b N Cl N N 25 B37 Si 1788911-46-5 30 S101c Cl NNN B38 O 35 Foreignfiling_text P24-134.doc - 113 - 1883265-36-8 S101c Cl N B39 N 5 N 1835683-69-6 S101b Cl N 10 NN B40 O 15 2305348-66-5 S101b Cl NNNO B41 20 O 2437221-69-5 S101c 25 B42 30 1788911-46-5 35 Foreignfiling_text P24-134.doc - 114 - S101b B43 5 1788911-46-5 S103a 10 B100 2915-16-4 S107a 15 B101 20 2286234-09-9 S103b 25 B102 2305895-68-3 30 S108a B103 35 1528738-48-8 Foreignfiling_text P24-134.doc - 115 - S108b B104 5 1421599-30-5 S106b 10 B105 1 592541-57-5 S101a 15 B106 20 2041800-09-1 S105b 25 B200 1628819-30-6 30 B201 S101b 35 Foreignfiling_text P24-134.doc - 116 - 5 1628819-30-6 S104b 10 B202 1398394-27-8 15 S101b B203 20 1973473-88-9 S103c B300 25 1801325-93-8 S105c 30 B301 35 1821152-54-8 Foreignfiling_text P24-134.doc - 117 - S101a B302 5 2363033-70-7 S101b B303 10 1821152-34-4 S101c 15 B304 1 821152-68-4 20 Example B400: 25 30 A mixture of 6.78 g (10.0 mmol) S1a, 4.79 g (11.0 mmol) 4,6-Diphenyl- 2-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]-1,3,5-triazine 35 [1313018-07-3], 2.76 g (12.0 mmol) tripotassium phosphate monohydrate Foreignfiling_text P24-134.doc - 118 - [27176-10-9], 231 mg (0.2 mmol) Tetrakis-triphenylphosphinopalladium(0), 30 g glass beads (3 mm diameter) and 120 ml DMSO are stirred for 24 h at 100 °C. After complete conversion, the mixture is allowed to cool, poured into 200 ml of a water/methanol mixture (1:1 vv), stirred briefly, filtered off the precipitated solid, washed five times with 50 ml of a water/methanol mixture (1:1 vv) each time and five times with 30 ml of methanol each time, and dried under vacuum. The solid is dissolved in 300 ml of dichloromethane (DCM), filtered through a silica gel bed pre-flourished with DCM, and the filtrate is concentrated under vacuum at 40 °C with stirring, replacing the distilled-off DCM with methanol. The crystallized solid is filtered off, washed three times with 30 ml of methanol each time, and dried under vacuum. Further purification is carried out by repeated hot extraction crystallization (using common organic solvents or combinations thereof, preferably acetonitrile-DCM, 1:3 to 3:1 vv) or by chromatography and fractional sublimation or annealing under high vacuum. Yield: 5.87 g (6.5 mmol); 65%; Purity: approx. 99.9% by HPLC. Alternatively, analogous to MF Roll, ACS Nano, 2008, 2, 2, 320, silver(I) oxide in THF can be used as a base. The following compounds can be prepared analogously: Example: Starting materials Product S1a HO OH B 25 B401 NNNN 30 2378846-09-2 N 402 S1b 35 Foreignfiling_text P24-134.doc - 119 - HO OH BNNNN 5 2378846-09-2 S1c HO OH B 10 B403 NNNN 15 2378846-09-2 S1b HO OH B 20 B404 NNNC N 2259756-08-4 S6b 25 HO OH B B405 NNN 30 B52382780-04-5 35 Foreignfiling_text P24-134.doc - 120 - S6b HO OH B B406 NN 5 N 2308565-18-4 S1b OH B 10 OH B407 NNN 15 1612243-82-9 S2a OOB 20 B408 NNNO O 25 1835206-79-5 S3c HOB OH N 30 B409 NN 35 1987895-22-6 Foreignfiling_text P24-134.doc - 121 - S6a HOB OH NBN 5 410 N 2348302-22-5 10 S1b HO OH B B4 NN 15 11 NO 2378846-11-6 20 S1b HOB OH B412 NN 25 N 1821675-76-6 S2b 30 HO OH B B413 NNN 35 Foreignfiling_text P24-134.doc - 122 - 2408940-94-1 S1b OOB 5 B414 DNNDDDND DD DDD 10 2588144-81-2 S2b OB O 15 N B415 NNN 20 2305366-95-2 S1c OOB 25 B416 NNN 30 1312412-10-4 35 Foreignfiling_text P24-134.doc - 123 - S7a HO OH B B417 NN 5 NO 2378846-11-6 10 S1b HOO B OH B418 NNN 15 2396739-37-8 S1c 20 OOB B419 NNN 25 C N 2226916-97-6 LS7b HO OH B 30 B420 NNNN 35 2378846-09-2 Foreignfiling_text P24-134.doc - 124 - LS1a B421 5 1820037-43-1 LS1b 10 B422 15 1820037-43-1 LS1c 20 B423 25 1820037-43-1 LS1c OOB 30 B424 DNNDDDND DD D35DD Foreignfiling_text P24-134.doc - 125 - 2588144-81-2 LS1b OOBO 5 B425 NNN 2265924-57-8 10 LS8b OB O N 15 B426 NNN 20 2305366-95-2 LS1b HOB OH 25 N B427 NNO 30 B4282305626-41-7 35 Foreignfiling_text P24-134.doc - 126 - LS1b OB O N 5 N B428 NO 10 2287210-68-6 LS8b OBOO 15 NN B429 N 20 2417057-68-0 LS3a OH B OH N B430 N 25 N 1612243-82-9 30 B 431 LS1c 35 Foreignfiling_text P24-134.doc - 127 - HOB OH NNN 5 O 2259346-74-0 10 LS8c O 15 O B432 BONNN 20 2375521-29-0 LS7c OOB 25 O B433 NNN 30 2441038-37-3 B 434 LS1b 35 Foreignfiling_text P24-134.doc - 128 - OBOONNN 5 2265924-61-4 LS1b NC OH B OH 10 B435 NNN 2140928-48-7 15 LS1a OBO B436 NN 20 NN 1971914-46-1 LS1b 25 OBO B437 NN 30 NN 1971914-46-1 35 Foreignfiling_text P24-134.doc - 129 - LS1c OBO B438 5 NNNN 1971914-46-1 10 S8a B500 15 1260393-76-7 S4b 20 B501 25 1689538-49-5 S4c 30 B502 2263909-91-5 35 Foreignfiling_text P24-134.doc - 130 - LS1b B503 5 2376611-44-6 10 S5b B504 15 1835206-54-6 LS1b 20 B505 2092371-64-5 25 LS1b B600 30 2245332-73-2 35 Foreignfiling_text P24-134.doc - 131 - LS1b B601 5 1821395-31-6 S1b 10 B700 15 2403814-83-3 LS1b 20 B701 2660012-61-1 25 LS1b 30 B800 2822550-66-1 35 Foreignfiling_text P24-134.doc - 132 - Example: Production of OLEDs The production of OLEDs according to the invention, as well as OLEDs according to the prior art, is carried out according to a general method according to WO 2004/058911, which is adapted to the conditions described here (layer thickness variation, materials used). 5 The following examples present the results of various OLEDs. Cleaned glass plates (cleaned in a Miele laboratory dishwasher, using Merck Extran cleaner), coated with structured ITO (indium tin oxide) of 50 nm thickness, are pretreated for 25 minutes with UV-Ozone 10 (UV-Ozone generator PR-100, UVP). These coated glass plates form the substrates onto which the OLEDs are applied. a) Blue Fluorescent OLED Devices – BF: 15 The compounds E according to the invention can be used in the hole-blocking layer (HBL) and/or the electron transport layer (ETL). All materials are thermally evaporated in a vacuum chamber. The emission layer (EML) always consists of at least one matrix material (host material) SMB (see Table 1) and an emitting dopant D, which is added to the matrix material(s) by co-evaporation in a specific volume fraction. A specification such as SMB:D (95%:5%) means that the material SMB is present in a volume fraction of 95% and the dopant D in a volume fraction of 5% in the layer. Similarly, the electron transport layer can also consist of a mixture of two materials, see Table 1. The materials used to produce the OLEDs are shown in Table 5. The OLEDs are characterized according to standard procedures. For this purpose, the 30 electroluminescence spectra, the current efficiency (measured in cd/A), the power efficiency (measured in lm/W), and the external quantum efficiency (EQE, measured in percent) are determined as a function of luminance, calculated from current-voltage-luminance characteristics (IUL characteristics) assuming a Lambertian emission characteristic. The 35 Foreignfiling_text P24-134.doc - 133 - The EQE in (%) and the voltage in (V) are specified at a luminance of 1000 cd/ m² . The OLEDs have the following layer structure: - Substrate 5 - Hole injection layer (HIL) made of HTM1 doped with 5% NDP-9 (commercially available from Novaled), 20 nm - Hole transport layer (HTL), made of HTM1, 180 nm - Electron blocking layer (EBL), see Table 1 - Emission layer (EML), see Table 1 10 - Hole blocking layer (HBL), see Table 1 - Electron transport layer (ETL), see Table 1 - Electron injection layer (EIL) made of ETM2, 1 nm - Cathode made of aluminum, 100 nm 15 Table 1: Structure of Blue Fluorescent OLED Devices Example EBL EML HBL ETL Thickness Thickness Thickness SMB1:D1 B1 EBM1 BF1 (95%:5%) --- 30 nm 10 nm 20 20 nm EBM1 SMB1:D1 B7 BF2 (95%:5%) 10 nm --- 30 nm 20 nm SMB2:D1 B26 EBM1 BF3 (95%:5%) --- 30 nm 25 10 nm 20 nm SMB3:D1 B414 EBM1 BF4 (95%:5%) --- 30 nm 10 nm 20 nm SMB3:D1 ETM1:ETM2 EBM1 (95%: B10 30 BF5 5%) (50%:50%) 10 nm 20 nm 5 nm 30 nm Table 2: Results Blue Fluorescent OLED Devices 35 Foreignfiling_text P24-134.doc - 134 - B sp. EQE (%) Voltage (V) B F1 9.1 4.3 BF2 8.5 4.2 BF3 9.3 4.5 5 BF4 8.8 4.4 BF5 8.7 4.6 b) Phosphorescent OLED components: 10 The compounds E according to the invention can be used, in particular, in the hole-blocking layer (HBL), the electron transport layer (ETL) and/or in the emission layer (EML) as an electron-conducting matrix material (host material) (hTMM or eTMM). For this purpose, all materials are thermally vapor-deposited in a vacuum chamber. The emission layer always consists of at least one or more matrix materials M and a phosphorescent dopant Ir, which is added to the matrix material(s) by co-evaporation in a specific volume fraction. A specification such as M1:M2:Ir (55%:35%:10%) means that material M1 is present in the layer at a volume fraction of 55%, M2 at a volume fraction of 35%, and Ir at a volume fraction of 10%. Similarly, the electron transport layer can also consist of a mixture of two materials. The exact structure of the OLEDs can be found in Table 3. The materials used to manufacture the OLEDs are shown in Table 5. The OLEDs are characterized according to standard procedures. For this purpose, the electroluminescence spectra, the current efficiency (measured in cd/A), the power efficiency (measured in lm/W), and the external quantum efficiency (EQE, measured in percent) are determined as a function of luminance, calculated from current-voltage-luminance characteristics (IUL characteristics) assuming a Lambertian emission characteristic. The EQE (%) and voltage (V) values are given at a luminance of 1000 cd/m². 35 Foreignfiling_text P24-134.doc - 135 - The OLEDs have the following layer structure: - Substrate - Hole injection layer (HIL) made of HTM1 doped with 5% NDP-9 (commercially available from Novaled), 20 nm - Hole transport layer (HTL) made of HTM1, 180 nm for blue, 50 nm for green, yellow, and red - Electron blocking layer (EBL), see Table 3 - Emission layer (EML), see Table 3 - Hole blocking layer (HBL), see Table 3 - Electron transport layer (ETL), see Table 3 - Electron injection layer (EIL) made of ETM2, 1 nm - Cathode made of aluminum, 100 nm Table 3: Structure of phosphorescent OLED components EML EBL HBL ETL 15 Example Thickness Thickness Thickness Blue B30:M4:IrB1 EBM2 HBM2 ETM1:ETM2 BP1 20 (40% (50%:50%) 20 nm :60%:5%) 5 nm 25 nm 30 nm B31:M4:IrB1 ETM1:ETM2 EBM2 HBM2 BP2 20 nm (40%:60%:5%) 5 nm (50%:50%) 25 nm 30 nm B31:M4:IrB1 ETM1:ETM2 EBM2 B31 25 BP3 20 nm (40%:60%:5%) 5 nm (50%:50%) 25 nm 30 nm Green M1:M2:IrG1 EBM1 HBM1 GP1 (30 B14 30 20 nm %:60%:10%) 5 nm 40 nm 30 nm EBM1 M1:M2:IrG1 HBM1 GP2 (30%:60%:10%) B20 20nm 5nm 40nm 30nm M1:M2:IrG1 ETM1:ETM2 EBM1 B430 GP3 20 (30%:60%:10%) (50%:50%) 35nm 5nm 40nm 30nm Foreignfiling_text P24-134.doc - 136 - Yellow M1:M2:IrG2 GP50 EBM1 (30%:60%:10%) HBM1 B12 20 nm 5 nm 40 nm 30 nm 5 M1:M2:IrG2 EBM1 HBM1 GP50 (30%:60%:10%) B13 20 nm 40 nm 5 nm 30 nm Red EBM1 B100:IrR1 HBM1 ETM1:ETM2 10 RP1 (92%:8%) (50%:50%) 20 nm 5 nm 35 nm 30 nm B201:IrR1 ETM1:ETM2 EBM1 HBM1 RP2 20 nm (90%:10%) 5 nm (50%:50%) 35 nm 30 nm EBM1 B303:IrR1 HBM1 ETM1:ETM2 15 RP3 (90%:10%) (50%:50%) 20 nm 5 nm 35 nm 30 nm B600:IrR1 B31 EBM1 B7 RP4 20 nm (90%:10%) 5 nm (50%:50%) 35 nm 30 nm 20 Table 4: Results Phosphorescent OLED Devices 25 30 35 Foreignfiling_text P24-134.doc - 137 - Blue Example EQE (%) Voltage (V) BP1 22.0 4.3 BP2 22.5 4.4 5 BP2 22.6 4.2 Green GP1 24.1 3.5 10 GP2 23.8 3.4 GP3 24.4 3.6 Yellow GP50 32.3 3.3 15 GP51 33.0 3.2 Red RP1 16.7 3.5 RP2 16.4 3.3 20 RP3 16.6 3.5 RP4 17.4 3.4 Table 5: Structural formulas of the materials used 25 NN 30 HTM1 136463-07-5 EBM1 1450933-44-4 35 Foreignfiling_text P24-134.doc - 138 - 5 EBM2 1206465-62-4 M1 1822310-86-0 10 NNNNN 15 M2 M3 = HBM2 1643479-47-31201800-83-0 20 M4 25 342638-54-4 HBM1 1955543-57-3 N Li 30 O ETM2 25387-93-3 ETM1 35 1819335-36-8 Foreignfiling_text P24-134.doc - 139 - 5 SMB1 1087346-88-0 SMB2 667940-34-3 Fluorescent Blue 10 ON SMB3 D1 15 1627916-48-6 1182175-27-4 Phosphorescent Blue Phosphorescent Green NN 20 NN Ir Ir N 3 N IrB1 IrG1 25 1541114-98-0 2245866-06-0 Phosphorescent deep red N Ir 30 Phosphorescent yellow 3 IrR1 35 1562420-79-4 Foreignfiling_text P24-134.doc - 140 - NN Ir 5 N 10 IrG2 2245945-28-0 15 20 25 30 35

Claims

Foreignfiling_text P24-134.doc - 141 - Claims 1. Compound according to formula (1), (R')7Si8O12-Ar-ETU Formula (1) 5 wherein the symbols used are defined as follows: ETU is an electron-transporting unit selected from the group consisting of triazine, pyrimidine, quinoxaline, 10 quinazoline, benzoquinazoline, benzoquinoxaline, benzimidazole, diazadibenzofuran, diazadibenzothiophene and diazacarbazole, wherein these groups may each be partially or completely deuterated and/or substituted by one or more R groups; 15 Ar is a bivalent aromatic or heteroaromatic ring system with 5 to 30 aromatic ring atoms, each of which may be partially or completely deuterated and/or substituted by ^one or more R groups; 20 R' is the same or different in each occurrence F, OR ¹ , a straight-chain alkyl group with 1 to 20 C atoms or a branched or cyclic alkyl group with 3 to 20 C atoms, wherein the alkyl group may in each case be partially or completely deuterated 25 and/or substituted with one or more R ¹ substituents, wherein one or more non-adjacent CH2 groups may be replaced by Si(R ¹ )2, C=O, NR ¹ , O, S or CONR ¹ , or an aromatic ring system with 6 to 12 aromatic ring atoms, which may in each case be partially or completely deuterated 30 and/or substituted with one of the several R ¹ substituents; R is the same or different in each occurrence H, D, F, N(R ¹ )2, CN, NO2, OR ¹ , SR ¹ , COOR ¹ , C(=O)N(R ¹ )2, Si(R ¹ )3, B(OR ¹ )2, 35 C(=O)R ¹ , P(=O)(R ¹ )2, S(=O)R ¹ , S(=O)2R ¹ , OSO2R ¹ , an even- Foreignfiling_text P24-134.doc - 142 - chain alkyl group with 1 to 20 C atoms or an alkenyl or alkynyl group with 2 to 20 C atoms or a branched or cyclic alkyl group with 3 to 20 C atoms, wherein the alkyl, alkenyl or alkynyl group may each be substituted with one or more ^R1 residues, wherein one or more non-adjacent CH2 groups may be replaced by Si( ^R1 )2, C=O, ^NR1 , O, S or ^CONR1 , or an aromatic or heteroaromatic ring system with 5 to 40 aromatic ring atoms, which may be substituted with one of the several ^R1 residues; wherein two R residues may also form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system; ^R1 is the same or different in each occurrence: H, D, F, Cl, Br, I, N( ^R2 )2, CN, NO2, ^OR2 , ^SR2 , Si( ^R2 )3, B( ^OR2 )2, C(=O) ^R2 , P(=O)( ^R2 )2, S(=O) ^R2 , S(=O) ^2R2 , ^OSO2R2 , a straight-chain alkyl group with 1 to 20 carbon atoms, or an alkenyl or alkynyl group with 2 to 20 carbon atoms, or a branched or cyclic alkyl group with 3 to 20 carbon atoms, wherein the alkyl, alkenyl, or alkynyl group may each be substituted with one or more ^R2 substituents, wherein one or more non-adjacent CH2 groups are replaced by Si(R2)20. ² )2, C=O, ^NR2 , O, S or ^CONR2 may be replaced and wherein one or more H atoms in the alkyl, alkenyl or alkynyl group may be replaced by D, F, Cl, Br, I or CN, or an aromatic or heteroaromatic 25 ring system with 5 to 40 aromatic ring atoms, each of which may be substituted by one or more ^R2 residues; wherein two or more ^R1 residues may form an aliphatic, aromatic or heteroaromatic ring system; 30 ^R2 is, in each occurrence, the same or different H, D, F, CN or an aliphatic, aromatic or heteroaromatic organic residue, in particular a hydrocarbon residue, with 1 to 20 C atoms, in which one or more H atoms may also be replaced by F35. Foreignfiling_text P24-134.doc - 143 - 2. Compound according to claim 1, characterized in that the group ETU is selected from the structures of formulas (ETU-1) to (ETU-13), 5 10 15 RRRRRRRRRNRRRRRRRN 20 _NN RRRN _N (ETU-10) (ETU-8) (ETU-9) RRRREERNNRNR 25 RNNNRRRRRRR (ETU-11) (ETU-12) (ETU-13) wherein R has the meanings mentioned in claim 1, E stands for O, 30 S or NR and the dashed bond indicates the bond to Ar. 3. Compound according to claim 1 or 2, characterized in that the group ETU is selected from the structures of formulas (ETU- 35 1a) to (ETU-13a), Foreignfiling_text P24-134.doc - 144 - 5 10 NRRRN 15 _{NN NN} (ETU-10a) (ETU-8a) (ETU-9a) REENN 20 NNNNRR ( 11a) (ET ETU-13a) (ETU- U-12a) wherein the symbols used have the 25 meanings mentioned in claims 1 and 2 and the structures may also be partially or completely deuterated. 4. Compound according to claim 3, characterized in that the R groups in structures (ETU-1a) to (ETU-13a) represent an aromatic or heteroaromatic ring system with 6 to 30 aromatic ring atoms, each of which may also be partially or completely deuterated and/or substituted with one or more ^R groups, and that, where E represents NR, the R group bonded to the N atom represents an aromatic or heteroaromatic ring system with 6 to 30 aromatic ring atoms, each of which Foreignfiling_text P24-134.doc - 145 - may also be partially or completely deuterated and/or substituted with one or more ^R1 groups. 5. Compound according to one or more of claims 1 to 4, characterized in that R is selected in each instance as the same or as different from the group consisting of H, D, F, CN, ^OR1 , a straight-chain alkyl group with 1 to 10 carbon atoms or an alkenyl group with 2 to 10 carbon atoms or a branched or cyclic alkyl group with 3 to 10 carbon atoms, wherein the alkyl or alkenyl group may each be substituted with one or more ^R1 groups, but preferably is unsubstituted, or an aromatic or heteroaromatic ring system with 6 to 30 aromatic ring atoms, which may be substituted with one or more ^R1 groups; Two adjacent R groups can also form an aliphatic, aromatic, or heteroaromatic ring system. 6. Compound according to one or more of claims 1 to 5, characterized in that the group Ar is selected from the group consisting of phenylene, biphenyl, terphenyl, fluorene, spirobifluorene, carbazole, dibenzofuran, or dibenzothiophene, wherein these groups may each be partially or completely deuterated and/or substituted with one or more ^R groups. 7. Compound according to one or more of claims 1 to 6, 25, characterized in that Ar is selected from the groups of formulas (Ar-1) to (Ar-12), R ¹ R ¹ R ¹ R ¹ R ¹ R ¹ 30 _{* #} * R ¹ * R ¹ R ¹ R ¹ R ¹ # # R ¹ (Ar-1) (Ar-2) ^(Ar-3) 35 Foreignfiling_text P24-134.doc - 146 - 5 10 15 20 25 wherein the symbols used have the meanings specified in claim 1, the dashed bond marked with * represents the bond to silicon and the dashed bond marked with # represents the bond to ETU. 30 8. Compound according to one or more of claims 1 to 7, characterized in that Ar is selected from the groups of formulas (Ar-1a) to (Ar-12a), 35 Foreignfiling_text P24-134.doc - 147 - * _# * * # # (Ar-1a) (Ar-2a) (Ar-3a) * _# * 5 (Ar-4a) (Ar-5a) # * * * 10 # (Ar-6a) (Ar-7a) # _{# (Ar-8a)} * * * * 15 # # (Ar-9a) _{# (Ar-10a)} # (Ar-12a) (Ar-11a) 20 wherein the symbols used have the meanings mentioned in claim 7 and the structures may be partially or completely deuterated. 9. Compound according to one or more of claims 1 to 8, 25 characterized in that R' is selected from OR ¹ , either the same or different at each occurrence, wherein R ¹ in the group OR ¹ represents a straight-chain alkyl group with 1 to 4 carbon atoms or a branched or cyclic alkyl group with 3 to 6 carbon atoms, wherein the alkyl group may also be partially or completely deuterated, 30 or a straight-chain alkyl group with 1 to 6 carbon atoms or a branched or cyclic alkyl group with 3 to 6 carbon atoms, wherein the alkyl group may also be partially or completely deuterated. 35 Foreignfiling_text P24-134.doc - 148 - 10. Compound according to one or more of claims 1 to 9, characterized in that R' represents, in each instance, a straight-chain alkyl group with 1, 2, 3, or 4 carbon atoms or a branched alkyl group with 3, 4, or 5 carbon atoms, wherein the alkyl group may be partially or completely deuterated. 11. Use of a compound according to one or more of claims 1 to 10 in an electronic device. 12. Electronic device comprising one or more compounds according to one or more of claims 1 to 10. 13. Electronic device according to claim 12, wherein it is an organic electroluminescent device, characterized in that the compound according to one or more of claims 1 to 10 is used as an electron transport material in an electron transport layer and/or a hole-blocking layer. 14. Electronic device according to claim 12 or 13, wherein it is an organic electroluminescent device, characterized in that the compound according to one or more of claims 1 to 10 is used in an emitting layer as a matrix material 25 for phosphorescent emitters, fluorescent emitters, or emitters exhibiting TADF (thermally activated delayed fluorescence). 15. Electronic device according to claim 14, characterized in that the compound according to one or more of claims 1 to 10 is used in combination with a further matrix material selected from carbazole, indenocarbazole, indolocarbazole, or triarylamine derivatives. 35