Nitrogen-containing hetreocycles for organic electroluminescent devices

Abstract

The present invention relates to nitrogen-containing heterocycles that are suitable for use in electronic devices, and to electronic devices, in particular organic electroluminescent devices, containing these heterocycles.

Description

[0001] Nitrogen-containing heterocycles for organic electroluminescent devices

[0002] The present invention relates to nitrogen-containing heterocycles for use in electronic devices, in particular in organic electroluminescent devices, as well as to electronic devices, in particular organic electroluminescent devices, containing these materials.

[0003] In organic electroluminescent devices, phosphorescent organometallic complexes are often used as emitting materials. For quantum mechanical reasons, up to four times the energy and power efficiency is possible when using organometallic compounds as phosphorescence emitters. In general, there is still room for improvement in electroluminescent devices, especially in electroluminescent devices that exhibit triplet emission (phosphorescence). The properties of phosphorescent electroluminescent devices are not only determined by the triplet emitters used. The other materials used, such as matrix materials, are also of particular importance. Improvements to these materials can therefore also lead to significant improvements in the properties of the electroluminescent devices.

[0004] In addition to an emission layer, many electroluminescent devices comprise additional 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 charge generation layers. These layers have a significant impact on the performance of electroluminescent devices.

[0005] Among other things, the electroluminescent devices described above are described in document US 2023 / 0301182 A1. In general, these materials, for example for use as matrix materials, still require improvement, particularly with regard to lifetime, but also with regard to the efficiency and operating voltage of the device.

[0006] The object of the present invention is therefore to provide compounds which are suitable for use in an organic electronic device, in particular in an organic electroluminescent device, and which, when used in this device, lead to good device properties, as well as to provide the corresponding electronic device.

[0007] In particular, the object of the present invention is to provide compounds that result in a long lifetime, good efficiency, and low operating voltage. Electron-injection materials, electron-transport materials, and hole-blocking materials contribute in particular to these properties. Furthermore, the properties of the matrix materials, also referred to herein as host materials, also have a significant influence on the lifetime and efficiency of the organic electroluminescent device.

[0008] Furthermore, it is the object of the present invention to provide compounds which are characterized by a low refractive index (RI).

[0009] A further object of the present invention can be seen in providing compounds suitable for use in phosphorescent or fluorescent electroluminescent devices, in particular as matrix materials. In particular, it is an object of the present invention to provide matrix materials suitable for green or blue phosphorescent electroluminescent devices and, optionally, also for red or yellow phosphorescent electroluminescent devices. Furthermore, the compounds, particularly when used as host material, electron injection material, electron transport material, or hole-blocking material in organic electroluminescent devices, should lead to devices exhibiting excellent color purity.

[0010] Another task can be seen in providing electronic devices with excellent performance as cost-effectively as possible and in consistent quality

[0011] Furthermore, the electronic devices should be able to be used or adapted for a variety of purposes. In particular, the performance of the electronic devices should be maintained over a wide temperature range.

[0012] Surprisingly, it has been found that certain compounds, described in more detail below, solve this problem, are well suited for use in electroluminescent devices, and lead to organic electroluminescent devices that exhibit very good properties, particularly with regard to lifetime, color purity, efficiency, operating voltage, and refractive index. These compounds, as well as electronic devices, in particular organic electroluminescent devices, containing such compounds, are therefore the subject of the present invention.

[0013] The present invention relates to a compound according to formula (I), where the group Q is selected from structures of the formula (Q-1 ),

[0014] where the dashed bond represents the bond to the group L or, in the case of q=0, to the dibenzofuran skeleton according to formula (I), s is 1, 2 or 3, preferably 1, where in the case of q=0 the index s is 1, and the following applies to the other symbols:

[0015] X is the same or different at each occurrence N or CR C , preferably N, where at least one of the groups X is N, preferably both of the groups X are N;

[0016] X a is the same or different at each occurrence N, CR a or, in the event that at this point this group binds to another group, C, preferably CR a or C, where at most two of the groups X a per ring represent N, preferably at most one of the groups X a per ring represents N and particularly preferably all groups X a for CR a or C;

[0017] X bis the same or different at each occurrence N, CR b or, in the event that at this point this group binds to another group, C, preferably CR b or C, where at most two of the groups X b per ring represent N, preferably at most one of the groups X b per ring represents N and particularly preferably all groups X b for CR b or C;

[0018] L is, at each occurrence, identically or differently, a bivalent, trivalent or tetravalent aromatic or heteroaromatic ring system having 6 to 40 aromatic ring atoms, each of which is substituted by one or more radicals R d may be substituted other than H; q is 0 or 1, where q = 0 means that the group L is not present and that the group Q is directly bonded to the corresponding atom, for example a carbon atom, of the dibenzofuran basic structure according to formula (I);

[0019] R is, identically or differently at each occurrence, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 10 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 10 C atoms, each of which is substituted by one or more radicals R 2 may be substituted by other than H, preferably a straight-chain alkyl group having 1 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms, each substituted by one or more radicals R 2 may be substituted by other than H, whereby two or more, preferably adjacent, substituents R may form a ring with each other;

[0020] R a , R b is, at each occurrence, the same or different: H, D, OH, F, CI, Br, I, CN, NO2, N(Ar)2, N(R C )2, C(=O)N(Ar)2, C(=O)N(R c )2, C(Ar)3, C(R C )3, Si(Ar)3, Si(R c )3, Ge(Ar)3, Ge(R c )3, B(Ar)2, B(R C )2, C(=O)Ar, C(=O)R C, P(=O)(Ar)2, P(=O)( R C )2, P(Ar)2, P(R C )2, S(=O)Ar, S(=O)R C , S(=O)2Ar, S(=O)2R C , OSO2Ar, OSO2R C , a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms or an alkenyl or alkynyl group having 2 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 C atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl or alkynyl group is each substituted with one or more radicals R c may be substituted by other than H, where one or more non-adjacent CH2 groups are substituted by R c C=CR c , C=C, Si(R c )2, C=O, C=S, C=Se, C=NR C , -C(=O)O-, -C(=O)NR C -, NR C , P(=O)(R C ), -O-, -S-, SO or SO2, or an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, each of which is substituted by one or more radicals R cmay be substituted by other than H, or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R c can be substituted, two radicals R a , R b also with each other or a residue R a , R b with another group, in particular a residue R c form a ring;

[0021] Ar is, at each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which is substituted by one or more radicals R c may be substituted by other than H, preferably Ar represents, identically or differently at each occurrence, an aryl or heteroaryl group having 6 to 20 aromatic ring atoms which may be substituted by one or more radicals R c may be substituted other than H, where the group Ar, in the case that X is CR C is, with the remainder R c the group X can form a ring;

[0022] R c , R d is, at each occurrence, the same or different: H, D, OH, F, CI, Br, I, CN, NO2, N(Ar')2, N(R 1 )2, C(=O)N(Ar')2, C(=O)N(R 1 )2, C(Ar')3, C(R 1 )3, Si(Ar')3, Si(R 1 )3, Ge(Ar')3, Ge(R 1 )3, B(Ar')2, B(R 1 )2, C(=O)Ar', C(=O)R 1 , P(=O)(Ar')2, P(=O)(R 1 )2, P(Ar')2, P(R 1 )2, S(=O)Ar', S(=O)R 1 , S(=O)2Ar', S(=O)2R 1 , OSO2Ar', OSO2R 1 , a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms or an alkenyl or alkynyl group having 2 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 C atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl or alkynyl group is each substituted by one or more radicals R 1 may be substituted by other than H, where one or more non-adjacent CH2 groups are substituted by R 1 C=CR 1, C=C, Si(R 1 )2, C=O, C=S, C=Se, C=NR 1 , -C(=O)O-, -C(=O)NR 1 - NR 1 , P(=O)(R 1 ), -O-, -S-, SO or SO2, or an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, each of which is substituted by one or more radicals R 1 may be substituted by other than H, or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R 1 may be substituted by other than H, two residues may be selected from the groups R c , R d also with each other or a residue R c or R d with another group, in particular a residue R a or R b form a ring; Ar' is at each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which with one or more radicals R 1may be substituted by other than H, whereby two radicals Ar' which are bonded to the same C-atom, Si-atom, N-atom, P-atom or B-atom may also be connected by a single bond or a bridge selected from B(R 1 ), C(R 1 )2, Si(R 1 )2, C=O, C=NR 1 , C=C(R 1 )2, 0, S, S=O, SO2, N(R 1 ), P(R 1 ) and P(=O)R 1 , be bridged together;

[0023] R 1 is, at each occurrence, the same or different: H, D, F, CI, Br, I, CN, NO2, N(Ar”)2, N(R 2 )2, C(=O)Ar”, C(=O)R 2 , P(=O)(Ar”)2, P(Ar”)2, B(Ar”)2, B(R 2 )2, C(Ar”)3, C(R 2 )3, Si(Ar”)3, Si(R 2 )3, Ge(Ar”)3, Ge(R 2 )3, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 40 C atoms or an alkenyl group having 2 to 40 C atoms, each of which is substituted by one or more radicals R2 may be substituted by other than H, where one or more non-adjacent CH2 groups are substituted by -R 2 C=CR 2 -, -C=C-, Si(R 2 )2, C=O, C=S, C=Se, C=NR 2 , -C(=O)O-, -C(=O)NR 2 -, NR 2 , P(=O)(R 2 ), -O-, -S-, SO or SO2 and where one or more H atoms can be replaced by D, F, CI, Br, I, CN or NO2, or an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, each substituted by one or more radicals R 2 may be substituted, or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R 2 may be substituted, or an aralkyl or heteroaralkyl group having 5 to 60 aromatic ring atoms which may be substituted with one or more radicals R 2may be substituted by other than H, or a combination of these systems; two or more, preferably adjacent, radicals R 1 form a ring with each other, whereby one or more radicals R 1 form a ring with another part of the compound;

[0024] Ar” is at each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, which is substituted by one or more radicals R 2 may be substituted, whereby two radicals Ar” which bind to the same C-atom, Si-atom, N-atom, P-atom or B-atom may also be linked by a single bond or a bridge selected from B(R 2 ), C(R 2 )2, Si(R 2 )2, C=O, C=NR 2 , C=C(R 2 )2, 0, S, S=O, SO2, N(R 2 ), P(R 2 ) and P(=O)R 2 , be bridged together;

[0025] R 2is selected, identically or differently at each occurrence, from the group consisting of H, D, F, CN, an aliphatic hydrocarbon radical having 1 to 20 C atoms or an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, in which one or more H atoms may be replaced by D, F, CI, Br, I or CN and which may be substituted by one or more alkyl groups each having 1 to 4 carbon atoms, where two or more, preferably adjacent, substituents R 2 form a ring with each other.

[0026] An aryl group within the meaning of this invention contains 6 to 40 C atoms; a heteroaryl group within the meaning of this invention contains 3 to 40 C atoms and at least one heteroatom, with the proviso that the sum of C atoms and heteroatoms is at least 5. The heteroatoms are preferably selected from N, O and / or S. An aryl group or heteroaryl group is understood to be either a simple aromatic cycle, i.e. benzene, or a simple heteroaromatic cycle, for example pyridine, pyrimidine, thiophene, etc., or a condensed (fused) aryl or heteroaryl group, for example naphthalene, anthracene, phenanthrene, quinoline, isoquinoline, etc. Aromatics linked to one another by a single bond, such as biphenyl, are not referred to as aryl or heteroaryl groups, but as an aromatic ring system.

[0027] An aromatic ring system within the meaning of this invention contains 6 to 60, preferably 6 to 40, carbon atoms in the ring system. An aromatic ring system within the meaning of this invention does not contain a heteroaryl group. A heteroaromatic ring system within the meaning of this invention contains 3 to 60 carbon atoms, preferably 3 to 40 carbon atoms, and at least one heteroaryl group, with the proviso that the sum of carbon atoms and heteroatoms is at least 5. The heteroatoms are preferably selected from N, O and / or S. An aromatic or heteroaromatic ring system within the meaning of this invention is to be understood as a system which does not necessarily contain only aryl or heteroaryl groups, but in which several aryl or heteroaryl groups can also be connected by a non-aromatic unit, such as a C, N or O atom. This also includes systems in which two or more aryl or heteroaryl groups are directly linked to one another, such as:Biphenyl, terphenyl, bipyridine, or phenylpyridine. For example, systems such as fluorene, 9,9'-spirobifluorene, 9,9-diarylfluorene, triarylamine, diaryl ether, stilbene, etc. are also to be understood as aromatic ring systems within the meaning of this invention, as are systems in which two or more aryl groups are linked, for example, by a linear or cyclic alkyl group or by a silyl group. 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 to one another, for example biphenyl, terphenyl, quaterphenyl, or bipyridine, as well as fluorene or spirobifluorene.

[0028] In the context of the present invention, an aliphatic hydrocarbon radical or an alkyl group or an alkenyl or alkynyl group which may contain 1 to 20 C atoms and in which individual H atoms or CH2 groups may be substituted by the above-mentioned groups, preferably the radicals methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl, neo-pentyl, cyclopentyl, n-hexyl, neo-hexyl, cyclohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, ethenyl, propenyl, butenyl, pentenyl, Cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, pentinyl, hexynyl, heptynyl or octynyl.Unter einer Alkoxygruppe mit 1 bis 40 C-Atomen werden bevor- zugt Methoxy, Trifluormethoxy, Ethoxy, n-Propoxy, i-Propoxy, n-Butoxy, i-Butoxy, s-Butoxy, t-Butoxy, n-Pentoxy, s-Pentoxy, 2-Methylbutoxy, n- Hexoxy, Cyclohexyloxy, n-Heptoxy, Cycloheptyloxy, n-Octyloxy, Cyclo- octyloxy, 2-Ethylhexyloxy, Pentafluorethoxy und 2,2,2-Trifluorethoxy ver- standen. Unter einer Thioalkylgruppe mit 1 bis 40 C-Atomen werden ins- besondere Methylthio, Ethylthio, n-Propylthio, i-Propylthio, n-Butylthio,.

[0029] 1-Butylthio, s-Butylthio, t-Butylthio, n-Pentylthio, s-Pentylthio, n-Hexylthio, Cyclohexylthio, n-Heptylthio, Cycloheptylthio, n-Octylthio, Cyclooctylthio,

[0030] 2-Ethylhexylthio, trifluoromethylthio, pentafluoroethylthio, 2,2,2-trifluoroethylthio, ethenylthio, propenylthio, butenylthio, pentenylthio, cyclopentenylthio, hexenylthio, cyclohexenylthio, heptenylthio, cycloheptenylthio, octenylthio, cyclooctenylthio, ethynylthio, propynylthio, butynylthio, pentynylthio, hexynylthio, heptynylthio, or octynylthio. In general, alkyl, alkoxy, or thioalkyl groups according to the present invention can be straight-chain, branched, or cyclic, where one or more non-adjacent CH2 groups can be replaced by the above-mentioned groups; Furthermore, one or more H atoms can be replaced by D, F, Cl, Br, I, CN or NO2, preferably F, Cl or CN, more preferably F or CN, particularly preferably CN.

[0031] An aromatic or heteroaromatic ring system with 5 - 60 or 5 to 40 aromatic ring atoms, which may also be substituted with the above-mentioned radicals and which may be linked to the aromatic or heteroaromatic ring via any position, is understood to mean, 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, iso- benzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, pyridine, quinoline, iso-quinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-chinolin, Phenothiazin, Phenoxazin, Pyrazol, Indazol, Imidazol, Benzimidazol, Naphthimidazol, Phenanthrimidazol, Pyridimidazol, Pyrazin- imidazol, Chinoxalinimidazol, Oxazol, Benzoxazol, Naphthoxazol, Anthroxazol, Phenanthroxazol, Isoxazol, 1 ,2-Thiazol, 1 ,3-Thiazol, Benzo- thiazol, Pyridazin, Hexaazatriphenylen, Benzopyridazin, Pyrimidin, Benz- pyrimidin, Chinoxalin, 1 ,5-Diazaanthracen, 2,7-Diazapyren, 2,3-Diaza- pyren, 1 ,6-Diazapyren, 1 ,8-Diazapyren, 4,5-Diazapyren, 4,5,9, 10-Tetra- azaperylen, Pyrazin, Phenazin, Phenoxazin, Phenothiazin, Fluorubin, Naphthyridin, Azacarbazol, Benzocarbolin, Phenanthrolin, 1 ,2,3-Triazol, 1 ,2,4-Triazol, Benzotriazol, 1 ,2,3-Oxadiazol, 1 ,2,4-Oxadiazol, 1 ,2,5-Oxa- diazol, 1 ,3,4-Oxadiazol, 1 ,2,3-Thiadiazol, 1 ,2,4-Thiadiazol, 1 ,2,5-Thiadi- azol, 1 ,3,4-Thiadiazol, 1 ,3,5-Triazin, 1 ,2,4-Triazin, 1 ,2,3-Triazin, Tetrazol, 1 ,2,4,5-Tetrazin, 1 ,2,3,4-Tetrazin, 1 ,2,3,5-Tetrazin, Purin, Pteridin, Indolizin und Benzothiadiazol oder Gruppen,which are derived from combinations of these systems.,

[0032] For the purposes of this description, the phrase "two or more residues can form a ring" is understood to mean, among other things, that the two residues are linked by a chemical bond with the formal elimination of two hydrogen atoms. This is illustrated by the following scheme.

[0033] 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:

[0034] In a preferred embodiment, it can be provided that the compound corresponds to the following formula (Ha), (Hb), (Hc) or (lld),

[0035] where the symbols R, Q, L, q, s, R a , R b and R c have the meanings given above, in particular for formula (I) and j is 2 or 3, i is 1 or 2 and k is 0 or 1, where the sum of both j is 5, the sum of both i is 3 and the sum of j and k is 3.

[0036] In formula (Ha) the sum of both indices j is 5, so that the group - (L)q-(Q)s at the point connected with the groups R a or with the group R b ring of the dibenzofuran skeleton. The same statement applies to formula (Hd), where the sum of both i is 3.

[0037] Similarly, the sum of j and k in formulas (Hb) and (Hc) is 3, so the group -(L) q -(Q) S at which the groups R a or with the group R b ring of the dibenzofuran skeleton.

[0038] In a further preferred embodiment, it can be provided that the group Q in formula (L) q -(Q) s is selected from structures of formulas (Q-2) to (Q-16), where the dashed bond represents the bond to the group L or, in case q= 0, to the dibenzofuran skeleton according to formula (I) and the symbols R c and Ar have the meanings given above, in particular for formula (I) and the following applies to the other symbols:

[0039] X c is the same or different at each occurrence N or CR C , preferably CR C , where at most two of the groups X c per ring represent N, preferably at most one of the groups X c per ring represents N and particularly preferably all groups X c for CR C or C; and

[0040] Y c is chosen from C(R C )2, Si(R c )2, Ge(R c )2, NR C, 0 or S, preferably NR C or 0, more preferably 0.

[0041] Structures of formula (Q-2), (Q-3) and (Q-11) are preferred and structures of formula (Q-2) are particularly preferred.

[0042] Furthermore, it can be provided that at least one radical Ar, preferably both radicals Ar in formulas (Q-1) to (Q-16) is / are selected from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthalene, indole, benzofuran, benzothiophene, carbazole, benzimidazolobenzimidazole, dibenzofuran, dibenzothiophene, indenocarbazole, indolocarbazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, isoquinoline, quinazoline, quinoxaline, phenanthrene or triphenylene, which are each substituted with one or more radicals R c may be substituted by other than H, preferably phenyl, biphenyl, fluorene, dibenzofuran, carbazole, triphenylene, indolocarbazole, particularly preferably phenyl, biphenyl, dibenzofuran.

[0043] In a particularly preferred embodiment, the compound according to the invention corresponds to one of the following formulas (III-1) to (III-27)

[0044]

[0045] where the symbols R, Q, L, q, s, R a , R b and R c have the meanings given above, in particular for formula (I), and j is 2 or 3, where Q is preferably selected from a structure according to one of the formulas (Q-2) to (Q-16), preferably one of the formulas (Q-2), (Q-3) and (Q-11), and particularly preferably the formula (Q-2). Structures of the formulas (III-2), (III-3), (III-8), (III-13), (III-14), (III-26) and (III-27) are preferred. Under the representation ' 2, drawn in a ring, it is to be understood that at each of the two free positions on the ring a residue R b is bound, where the residues R b can be the same or different each time they occur.

[0046] For similar representations, such as corresponding definitions apply, where the remainder R d is bound to the corresponding ring and there are four free positions to which the residues are bound, which may be the same or different at each occurrence.

[0047] Preferably, it can be provided that the radical L is selected on each occurrence, identically or differently, from divalent, trivalent or tetravalent phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthalene, indole, benzofuran, benzothiophene, carbazole, benzimidazolobenzimidazole, dibenzofuran, dibenzothiophene, indenocarbazole, indolocarbazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, isoquinoline, quinazoline, quinoxaline, phenanthrene or triphenylene, which are each substituted with one or more radicals R d may be substituted by other than H.

[0048] In a particularly preferred embodiment, it can be provided that in formula (I), (Ha), (Hb), (Hc), (Hd) or (HI-1) to (HI-27) the group Q corresponds to the formula (Q-2), the index s is 1 and the index q is 0, wherein at least one of the radicals Ar, preferably both of the radicals Ar in formula is / are selected from phenyl, biphenyl, dibenzofuran, which are each substituted with one or more radicals R c may be substituted by other than H.

[0049] Furthermore, it can preferably be provided that in formula (I), (Ha), (Hb), (Hc), (Hd) or (HI-1) to (HI-27) the group Q corresponds to the formula (Q-3), (Q-11), (Q-12) or (Q-13), the index s is 1 and the index q is 0, wherein at least one of the radicals Ar, preferably both of the radicals Ar in formula is / are selected from phenyl, biphenyl, dibenzofuran, which are each substituted with one or more radicals R c may be substituted by other than H.

[0050] Furthermore, it can be provided that in formula (I), (Ha), (Hb), (Hc), (Hd) or (HI-1) to (HI-27) the group Q corresponds to the formula (Q-7), (Q-14), (Q-15) or (Q-16), the index s is 1 and the index q is 0, wherein at least one of the radicals Ar, preferably both of the radicals Ar in formula is / are selected from phenyl, biphenyl, dibenzofuran, which are each substituted with one or more radicals R c may be substituted by other than H.

[0051] In a further particularly preferred embodiment, it can be provided that in formula (I), (Ha), (Hb), (Hc), (Hd) or (HI-1) to (HI-27) the group Q corresponds to the formula (Q-2), the index s is 1 and the index q is 1, wherein the group L is selected from divalent phenyl, biphenyl, dibenzofuran, carbazole, which are each substituted with one or more radicals R dmay be substituted by other than H, wherein at least one of the radicals Ar, preferably both of the radicals Ar in formula is / are selected from phenyl, biphenyl, dibenzofuran, each of which is substituted by one or more radicals R c may be substituted by other than H.

[0052] Furthermore, it can preferably be provided that in formula (I), (Ha), (Hb), (Hc), (Hd) or (HI-1) to (HI-27) the group Q corresponds to the formula (Q-3), (Q-11), (Q-12) or (Q-13), the index s is 1 and the index q is 1, wherein the group L is selected from divalent phenyl, biphenyl, dibenzofuran, carbazole, which are each substituted with one or more radicals R d may be substituted by other than H, wherein at least one of the radicals Ar, preferably both of the radicals Ar in formula is / are selected from phenyl, biphenyl, dibenzofuran, each of which is substituted by one or more radicals R c may be substituted by other than H.

[0053] Furthermore, it can be provided that in formula (I), (Ha), (Hb), (Hc), (Hd) or (HI-1) to (HI-27) the group Q corresponds to the formula (Q-7), (Q-14), (Q-15) or (Q-16), the index s is 1 and the index q is 1, wherein the group L is selected from divalent phenyl, biphenyl, dibenzofuran, carbazole, which are each substituted with one or more radicals R d may be substituted by other than H, wherein at least one of the radicals Ar, preferably both of the radicals Ar in formula is / are selected from phenyl, biphenyl, dibenzofuran, which are each substituted by one or more radicals R c may be substituted by other than H.

[0054] In addition, it may be provided that the group -(L) q - in formula -(L)q-(Q)s a structure of the formula -(L d )0-, so that the group of the formula -(L) q -(Q) S is selected from structures of the formula -(L d)0-(Q)s, where the index o is 0, 1 , 2, 3, 4 or 5, where o = 0 means that the group L d is not present and that the group Q is directly bonded to the corresponding atom, for example a carbon atom, of the dibenzofuran skeleton according to formula (I), where o is preferably 0, 1 or 2 and particularly preferably 0 or 1 and the radical L d is chosen from structures of the formulas (L d -1 ) to (L d -13)

[0055] where the dashed bonds represent the attachment points and the other symbols are:

[0056] X d is the same or different at each occurrence N, CR d or, in the event that at this point this group binds to another group, C, preferably CR d or C, where a maximum of three of the groups X d per ring represent N, preferably at most two of the groups X dper ring represent N and particularly preferably all groups X d for CR d or C, where R d has the meaning given above, in particular for formula (I);

[0057] Y d is chosen from C(R d )2, NR d , 0 or S, preferably NR d or 0, particularly preferably NR d ; where the structure of the formula -(L d )0- for the index s =1 in formula -( L d )o-(Q)s is bivalent, for s=2 trivalent and for s=3 tetravalent.

[0058] Here, structures of the formulas (L d -1 ), (L d -2), (L d -4) and (L d -6) and structures of the formulas (L d -1 ) and (L d -2) is particularly preferred.

[0059] In a preferred embodiment, group L d selected from structures of the formulas (L d -14) to (L d -33) where the dashed bonds represent the attachment points, the symbol R d has the meaning given above, in particular for formula (I), the symbol X d which were previously used, especially for formulas (L d -1 ) to (L d -13) and for the other symbols: i is 1 or 2; and j is 0, 1 or 2.

[0060] Here, structures of the formulas (L d -14), (L d -16), (L d -17), (L d -19), (L d -20) and (L d -24) and structures of the formulas (L d -14), (L d -16) and (L d -17) is particularly preferred.

[0061] In a particularly preferred embodiment, it can be provided that in formula (I), (Ha), (Hb), (Hc), (Hd) or (III-1) to (III-27) the group Q corresponds to the formula (Q-2), the index s is 1 and the index o is 1, where the group L d is selected from structures of the formula (Ld -1 ), (L d -4), (L d -5), (L d -6), (L d -14), (L d -15), (L d -16), (L d -20), (L d -21 ), wherein at least one of the radicals Ar, preferably both of the radicals Ar in formula is / are selected from phenyl, biphenyl, dibenzofuran, each of which is substituted with one or more radicals R c may be substituted by other than H.

[0062] Furthermore, it can preferably be provided that in formula (I), (Ha), (Hb), (Hc), (Hd) or (HI-1) to (HI-27) the group Q corresponds to the formula (Q-3), (Q-11), (Q-12) or (Q-13), the index s is 1 and the index o is 1, where the group L d is selected from structures of the formula (L d -1 ), (L d -4), (L d -5), (L d -6), (L d -14), (L d -15), (L d -16), (L d -20), (L d-21 ), wherein at least one of the radicals Ar, preferably both of the radicals Ar in formula is / are selected from phenyl, biphenyl, dibenzofuran, each of which is substituted with one or more radicals R c may be substituted by other than H.

[0063] Furthermore, it can be provided that in formula (I), (Ha), (Hb), (Hc), (Hd) or (HI-1) to (HI-27) the group Q corresponds to the formula (Q-7), (Q-14), (Q-15) or (Q-16), the index s is 1 and the index o is 1, where the group L d is selected from structures of the formula (L d -1 ), (L d -4), (L d -5), (L d -6), (L d -14), (L d -15), (L d -16), (L d -20), (L d -21 ), wherein at least one of the radicals Ar, preferably both of the radicals Ar in formula is / are selected from phenyl, biphenyl, dibenzofuran, each of which is substituted with one or more radicals R c may be substituted by other than H.

[0064] In a preferred embodiment, the inventive

[0065] Compound of one of the following formulas (IV-1) to (IV-4) where the symbols R, X, X a , X b and Ar have the meanings given above, in particular for formula (I), the symbols X d and Y d which were previously used, especially for formulas (L d -1 ) to (L d -13). Structures of the formulas (IV-1) and (IV-2) are preferred.

[0066] Furthermore, in particular in formulas (IV-1 ) to (IV-4) it can be provided that at most two groups X a , X b , X d per ring for N, preferably all groups X a , X b , X d for groups CR a , CR b , CR d preferably at least one, particularly preferably at least two of the groups X a , X b , X dper ring are selected from CH and CD.

[0067] Furthermore, in particular in formulas (IV-1) to (IV-4) it can be provided that not more than four, preferably not more than two groups X a , X b , X d represent N, especially preferably all groups X a , X b , X d for groups CR a , CR b , CR d where preferably at most 4, particularly preferably at most 3 and especially preferably at most 2 of the groups CR a , CR b , CR d , for the X a , X b , X d is not equal to group CH or CD.

[0068] In a particularly preferred embodiment, the compound according to the invention corresponds to one of the following formulas (V-1) to

[0069] (V-37) where the symbols R, R a , R b , R c, R d and Ar have the meanings given above, in particular for formula (I), the symbol Y d which were previously used, especially for formulas (L d -1 ) to (L d -13) and for the other symbols the following applies: n is 2 or 3.

[0070] Furthermore, in particular in formulas (V-1) to (V-37) it can be provided that at most five, preferably at most four, particularly preferably at most three of the radicals R a , R b , R c , R d are not equal to H or D.

[0071] Structures of the formulas (V-1), (V-2), (V-4), (V-9), (V-10), (V-13), (V-14), (V-17), (V-18), (V-33), (V-34) and (V-37) are preferred and structures of the formulas (V-1), (V-2), (V-4), (V-33) and (V-37) are particularly preferred.

[0072] Furthermore, it can be provided that at least one of the radicals R a or R b a group of the formula -(L) q -(Q) Swhere L and Q have the meanings given above, in particular for formula (I), where Q is preferably selected from structures of the formulas (Q-2) to (Q-16), and q is 0 or 1 and s is 1, 2 or 3, preferably 1 or 2, where preferably exactly one of the radicals R a or R b a group of the formula -(L) q -(Q) S Compounds with exactly one group of the formula -(L) q -(Q) S are compared to compounds with two or three groups of the formula -(L) q -(Q) S preferred, the latter compounds being characterized in that one of the radicals R a or R b a group of the formula -(L) q -(Q) S corresponds.

[0073] Furthermore, it can be provided that at least one of the radicals R a or R b a group of the formula -(L d)0-(Q)s, Q has the meaning set out above, in particular for formula (I) and is preferably selected from structures of the formulas (Q-2) to (Q-16), and the index o is 0, 1, 2, 3, 4 or 5, preferably 0, 1 or 2 and particularly preferably 0 or 1, the index s is 1, 2 or 3, preferably 1 or 2, and the radical L d is chosen from structures of the formulas (L d -1 ) to (L d -33), these structures being set out above, wherein preferably exactly one of the radicals R a or R b a group of the formula -(L d )o-(Q)s. Compounds with exactly one group of the formula -(L d )o-(Q)s are more sensitive to compounds with two or three groups of the formula -(L d )0-(Q)s are preferred, the latter compounds being characterized in that one of the radicals R a or R b a group of the formula -(L d )0-(Q)s.

[0074] Preferably, it can be provided that at least one of the radicals R a or R b a group of the formula C(R)3, where R has the meaning given above, in particular for formula (I), where preferably exactly one or exactly two of the radicals R a or R b corresponds to a group of the formula C(R)3. Compounds with exactly three groups of the formula C(R)3 are preferred over compounds with exactly two groups of the formula C(R)3. These preferred compounds are characterized in that at least one of the radicals R a or R b a group of the formula C(R)3.

[0075] Preferably, it can be provided that at least one of the radicals R a or R brepresents an aromatic or heteroaromatic ring system having 6 to 18 aromatic ring atoms, preferably selected from phenyl, biphenyl, terphenyl, fluorene, spirobifluorene, dibenzofuran, particularly preferably phenyl, each of which is substituted with one or more radicals R c may be substituted, particularly preferably is unsubstituted, apart from D. Here, the aromatic or heteroaromatic ring system with 6 to 18 aromatic ring atoms is particularly preferably selected from the structures (Ar-1) to (Ar-3) and (Ar-13) to Ar-16 described later). Compounds in which exactly one or two of the radicals R a or R b represent an aromatic or heteroaromatic ring system with 6 to 18 aromatic ring atoms are preferred.

[0076] In one embodiment, it may be provided that the group Q does not comprise a carbazole group, preferably no hole transport group.

[0077] In one embodiment, the group L may not comprise a carbazole group, preferably a hole-transport group. Compounds in which the groups L and / or Q do not comprise a hole-transport group are particularly suitable as electron injection materials, electron transport materials, or hole-blocking materials used in a corresponding layer, which layer generally does not contain an emitting compound.

[0078] In a further embodiment, it can be provided that the group Q comprises a hole transport group, preferably a carbazole group.

[0079] In a further embodiment, it can be provided that the group L comprises a hole transport group, preferably a carbazole group.

[0080] Compounds in which the groups L and / or Q comprise an electron transport group are particularly suitable as host materials used in combination with an emitting compound.

[0081] Hole-transport groups are widely known in the scientific community. These include, in particular, carbazole groups and groups with similar properties.

[0082] In a preferred embodiment, it can be provided that the radical R a , R b , R c , R d does not comprise an aromatic or heteroaromatic ring system having three linearly condensed aromatic 6 rings, wherein preferably none of the radicals R a , R b , R c , R d an aromatic or heteroaromatic ring system having three linearly condensed aromatic 6-membered rings.

[0083] Particularly preferably, it can be provided that the residue R a , R b , Rc , R d does not comprise an aromatic or heteroaromatic ring system which has three fused aromatic 6 rings, wherein preferably none of the radicals R a , R b , R c , R d an aromatic or heteroaromatic ring system which has three fused aromatic 6-membered rings.

[0084] Furthermore, it can be provided that the compound does not comprise an aromatic or heteroaromatic ring system which has three aromatic 6 rings fused to one another.

[0085] In a preferred development of the present invention, it can be provided that at least two, preferably adjacent, radicals R a , R b , R c , R d with the other groups to which the two residues R a , R b , R c , R dbind, form a condensed ring. In a preferred embodiment, it can be provided that ring structures are formed which are described in the document WO 2022 / 079068 A1 , filed on 13.10.2021 with the European Patent Office under the application number PCT / EP2021 / 078240, wherein for disclosure purposes the description of the condensed ring structures set out in these documents, which are formed by the ring elements of the formulas (RA-1) to (RA-12), (RA-1 a) to (RA-4f) and / or (RB) on pages 37 to 40 of the document

[0086] WO 2022 / 079068 A1 are incorporated into the present application by reference thereto. The ring structures described above and further described in WO 2022 / 079068 A1, which preferably comprise the ring elements of the formulas (RA-1) to (RA-12) and (RA-1a) to (RA-4f), lead in particular to compounds according to the invention which have a surprisingly low refractive index.

[0087] Furthermore, it can be provided that the substituents R a , R b , R c , R d and R 1 according to the above formulas with the ring atoms of the ring system to which the substituents R a , R b , R c , R d and R 1 bind, do not form a fused aromatic or heteroaromatic ring system. This excludes the formation of a fused aromatic or heteroaromatic ring system with possible substituents R 1 and R 2 which are attached to the substituents R a , R b , R c , R d and R 1 may be bound.

[0088] If the compound according to the invention is reacted with aromatic or heteroaromatic groups R a , R b , R c , R d , R 1 or R 2is substituted, it is preferred if these do not contain any aryl or heteroaryl groups with more than two directly fused aromatic six-membered rings. Particularly preferably, the substituents do not contain any aryl or heteroaryl groups with directly fused six-membered rings. This preference is due to the low triplet energy of such structures. Condensed aryl groups with more than two directly fused aromatic six-membered rings that are nevertheless also suitable according to the invention are phenanthrene and triphenylene, since these also have a high triplet level.

[0089] Preferably, the group -(L) q -(Q) S or the group Q with the dibenzofuran group, to which the group -(L) q -(Q) Saccording to formula (I) or the preferred embodiments of this formula, form a continuous conjugation. Continuous conjugation of the aromatic or heteroaromatic systems is formed as soon as direct bonds are formed between adjacent aromatic or heteroaromatic rings. A further linkage between the aforementioned conjugated groups, for example, via an S, N, or O atom or a carbonyl group, does not harm the conjugation.

[0090] When two residues, which can be selected in particular from R, R a , R b , R c , R d , R 1 and / or R 2 , together form a ring, this ring can be mono- or polycyclic, aliphatic, heteroaliphatic and in the case of the radicals R a , R b , R c , R d , R 1 and / or R 2, aromatic or heteroaromatic. The residues that form a ring can be adjacent, ie these residues are attached to the same carbon atom or to carbon atoms that are directly bonded to each other, or they can be further apart. Furthermore, the radicals with the substituents R c , R d , R 1 and / or R 2 provided ring systems can also be connected to each other via a bond, so that a ring closure can be achieved.

[0091] Furthermore, it can be provided that at least one radical R a , R b , R c , R dis selected, identically or differently on each occurrence, from the group consisting of an aromatic or heteroaromatic ring system selected from the groups of the following formulas Ar-1 to Ar-76, and / or the group Ar' is selected, identically or differently on each occurrence, from the groups of the following formulas Ar-1 to Ar-76,

[0092] where R 1 has the meanings given above, the dashed bond represents the bond to the corresponding group and furthermore:

[0093] Ar 1 is at each occurrence, identically or differently, a bivalent aromatic or heteroaromatic ring system having 6 to 18 aromatic ring atoms, each of which is substituted by one or more radicals R 1 can be substituted; A is the same or different at each occurrence C(R 1 )2, NR 1, 0 or S; p is 0 or 1 , where p = 0 means that the group Ar 1 is not present and that the corresponding aromatic or heteroaromatic group is directly bonded to the corresponding residue; q is 0 or 1, where q = 0 means that no group A is bonded to this position and that the corresponding carbon atoms are bonded instead to residues R 1 are bound.

[0094] The previously presented structures of the formulas (Ar-1) to (Ar-76) represent preferred embodiments of the radicals R a or R b as defined, for example, in structures of formula (I), where in this case the substituents R 1 in formulas (Ar-1 ) to (Ar-76) by R c are to be replaced, where R c has the meaning set out above, in particular for formula (I).

[0095] Furthermore, the previously presented structures of the formulas (Ar-1) to (Ar-76) represent preferred embodiments of the radicals Ar, as defined, for example, in structures of the formula (I), wherein in this case the substituents R 1 in formulas (Ar-1 ) to (Ar-76) by R c are to be replaced, where R c has the meaning set out above, in particular for formula (I).

[0096] Structures of the formulas (Ar-1), (Ar-2), (Ar-3), (Ar-12), (Ar-13), (Ar-14), (Ar-15), (Ar-16), (Ar-40), (Ar-41), (Ar-42), (Ar-43), (Ar-44), (Ar-45), (Ar-46), (Ar-69), (Ar-70), (Ar-76) are preferred and structures of the formulas (Ar-1), (Ar-2), (Ar-3), (Ar-12), (Ar-13), (Ar-14), (Ar-15), (Ar-16) are particularly preferred.

[0097] If the above-mentioned groups for structures of the formulas (Ar-1) to (Ar-76) have several groups A, all combinations from the definition of A are possible. Preferred embodiments are then those in which a group A represents NR 1 and the other group A for C(R 1 )2 or in which both groups A for NR 1 or in which both groups A stands for 0. If A stands for NR 1 the substituent R 1 which is bonded to the nitrogen atom, preferably represents an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, which can also be substituted by one or more radicals R 2 In a particularly preferred embodiment, this substituent R 1identical or different on each occurrence for an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, in particular having 6 to 18 aromatic ring atoms, which has no condensed aryl groups and which has no condensed heteroaryl groups in which two or more aromatic or heteroaromatic 6-ring groups are directly fused to one another, and which in each case also by one or more radicals R 2 may be substituted. Phenyl, biphenyl, terphenyl and quaterphenyl are preferred. Triazine, pyrimidine and quinazoline are also preferred, as listed above for Ar-47 to Ar-50, Ar-57 and Ar-58, where these structures are substituted by R 1 by one or more residues R 2 can be substituted.

[0098] If A for C(R 1 )2, the substituents R 1which are bonded to this carbon atom, preferably identically or differently on each occurrence, represent a linear alkyl group having 1 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms or an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, which can also be substituted by one or more radicals R 2 R is particularly preferably 1 represents a methyl group or a phenyl group. The radicals R 1 also form a ring system with each other, which leads to a spiro system.

[0099] Preferred substituents R a , R b , R c and R d described.

[0100] In a preferred embodiment of the invention, R a , R b identically or differently at each occurrence selected from the group consisting of H, D, F, CN, NO2, Si(R c )s, B(ORC )2, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, wherein the alkyl group is in each case substituted with one or more radicals R 1 may be substituted, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, preferably having 5 to 40 aromatic ring atoms, each substituted by one or more radicals R c can be substituted.

[0101] In a preferred embodiment of the invention, R c , R d identically or differently at each occurrence selected from the group consisting of H, D, F, CN, NO2, Si(R 1 )s, B(OR 1 )2, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, wherein the alkyl group is in each case substituted with one or more radicals R 1may be substituted, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, preferably having 5 to 40 aromatic ring atoms, each substituted by one or more radicals R 1 can be substituted.

[0102] In a further preferred embodiment of the invention, substituent R a , R b , R c , R d identically or differently on each occurrence selected from the group consisting of H, D, F, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where the alkyl group is in each case substituted with one or more radicals R 1 may be substituted, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, preferably having 5 to 40 aromatic ring atoms, each substituted by one or more radicals R c or R 1 can be substituted by something other than H.

[0103] Furthermore, it can be provided that at least one radical R a , R b , R c , R d preferably a substituent R a , R b , R c , R d is selected, identically or differently at each occurrence, from the group consisting of H, D, an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, which is reacted with one or more radicals R 1 Particularly preferred is at least one substituent R c , R d is selected, identically or differently on each occurrence, from the group consisting of an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, which is substituted with one or more radicals R c or R 1 can be substituted by something other than H.

[0104] Particularly preferred is the radical R a , R b , R c , R didentically or differently on each occurrence selected from the group consisting of H, D or an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, preferably having 6 to 18 aromatic ring atoms, particularly preferably having 6 to 13 aromatic ring atoms, each of which is substituted with one or more radicals R c or R 1 can be substituted by something other than H.

[0105] Furthermore, it can be provided that at least one radical R a , R b , R c , R d represents an aromatic or heteroaromatic ring system with 5 to 13 aromatic ring atoms, which is substituted by one or more radicals R c or R 1 can be substituted by something other than H.

[0106] Preferably, it can be provided that at least one radical, preferably a substituent R a , R b , R c , R dis selected, identically or differently on each occurrence, from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthalene, indole, benzofuran, benzothiophene, carbazole, dibenzofuran, dibenzothiophene, indenocarbazole, indolocarbazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, isoquinoline, quinazoline, quinoxaline, phenanthrene or triphenylene, which are each substituted with one or more radicals R c or R 1 may be substituted by a group other than H. The term substituent means in particular that R a , R b , R c , R d are not equal to H. Furthermore, the substituents R a , R b , R c , R d be the same or different if two or more substituents are present which are selected from the aromatic or heteroaromatic group mentioned.

[0107] Furthermore, it can be provided that the groups R bonded to a C atom are the same.

[0108] Furthermore, it can be provided that the R groups bonded to different C atoms are the same. Furthermore, it can be provided that the R groups bonded to different C atoms are different.

[0109] Preferably, the groups R bonded to a C atom can be selected from straight-chain alkyl groups having 1 to 10 C atoms or branched or cyclic alkyl groups having 3 to 10 C atoms, each of which is bonded to one or more radicals R 2 may be substituted, preferably deuterated, whereby two or more substituents R may form a ring with each other.

[0110] Preferably, the group R stands for methyl, ethyl, propyl, or three groups R which bond to the same C atom form a bi- or tricycloalkyl radical having 9 or 10, preferably 9, carbon atoms, wherein the group R preferably stands for methyl, wherein these groups may be deuterated.

[0111] Preferred aromatic or heteroaromatic ring systems for which the substituents R a , R b , R c , R d or R 1, Ar or Ar' 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, in particular 1- or -linked naphthalene, 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, Indenocarbazole, indolocarbazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, isoquinoline, quinazoline, quinoxaline, anthracene, pyrene, perylene, chrysene, phenanthrene or triphenylene, each of which is substituted with one or more radicals Rc , R 1 or R 2 may be substituted. The structures Ar-1 to Ar-76 listed above are particularly preferred, with structures of the formulas (Ar-1), (Ar-2), (Ar-3), (Ar-12), (Ar-13), (Ar-14), (Ar-15), (Ar-16), (Ar-69), (Ar-70), (Ar-76) being preferred and structures of the formulas (Ar-1), (Ar-2), (Ar-3), (Ar-12), (Ar-13), (Ar-14), (Ar-15), (Ar-16) being particularly preferred. With regard to the structures Ar-1 to Ar-76, it should be noted that these can be substituted with a substituent R 1 In the case of the ring systems Ar and the residues R a , R b these substituents R 1 by R c to be replaced, in case of the remainders R 1 by R 2 .

[0112] In a further preferred embodiment of the invention, R 1identically or differently on each occurrence selected from the group consisting of H, D, F, CN, a straight-chain alkyl group having 1 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms, where the alkyl group is in each case substituted with one or more radicals R 2 may be substituted, or an aromatic or heteroaromatic ring system with 6 to 24 aromatic ring atoms, each substituted by one or more radicals R 2 may be substituted. In a particularly preferred embodiment of the invention, R 1 identically or differently on each occurrence selected from the group consisting of H, a straight-chain alkyl group having 1 to 6 C atoms, in particular having 1, 2, 3 or 4 C atoms, or a branched or cyclic alkyl group having 3 to 6 C atoms, where the alkyl group is substituted with one or more radicals R 2may be substituted, but is preferably unsubstituted, or an aromatic or heteroaromatic ring system having 6 to 13 aromatic ring atoms, each substituted by one or more radicals R 2 can be substituted, but is preferably unsubstituted.

[0113] In a further preferred embodiment of the invention, R 2 identical or different on each occurrence H, an alkyl group having 1 to 4 C atoms or an aryl group having 6 to 10 C atoms, which may be substituted by an alkyl group having 1 to 4 C atoms, but is preferably unsubstituted.

[0114] In compounds according to the invention that are processed by vacuum evaporation, the alkyl groups preferably have no more than five carbon atoms, particularly preferably no more than 4 carbon atoms, and most preferably no more than 1 carbon atom. Also suitable for compounds that are processed from solution are compounds that are substituted by alkyl groups, particularly branched alkyl groups, with up to 10 carbon atoms, or that are substituted by oligoarylene groups, for example ortho-, meta-, para-, or branched terphenyl or quaterphenyl groups.

[0115] In a preferred embodiment, the compounds are at least 50%, in particular at least 80%, particularly preferably fully (100%) deuterated. This means that in such a compound, the corresponding proportion of the hydrogen atoms contained in the undeuterated compound have been exchanged for D. The undeuterated compound is the corresponding compound in which the deuterium has been exchanged for hydrogen and therefore contains no D. In a fully deuterated compound, all H atoms are exchanged for D.

[0116] According to a preferred embodiment, part of the compound is completely undeuterated, and another part is largely or completely deuterated. According to a preferred embodiment, the Q group or the Q group and the L group may be largely or completely deuterated, and the other parts of the compound of formula (I) are completely undeuterated. According to an alternative preferred embodiment of the invention, the Q group or the Q group and the L group are completely undeuterated, and the remainder of the compound of formula (I) is largely or completely deuterated.

[0117] When the compounds of formula (I) or the preferred embodiments are used as matrix material for a phosphorescent emitter or in a layer directly adjacent to a phosphorescent layer, it is further preferred if the compound does not contain any condensed aryl or heteroaryl groups in which more than two six-membered rings are directly condensed to one another. Exceptions to this are phenanthrene and triphenylene, which may be preferred due to their high triplet energy despite the presence of condensed aromatic six-membered rings.

[0118] Preferably, compounds according to the invention have a

[0119] Molecular weight of less than or equal to 5000 g / mol, preferably less than or equal to 4000 g / mol, particularly preferably less than or equal to 3000 g / mol, especially preferably less than or equal to 2000 g / mol, more especially preferably less than or equal to 1200 g / mol and very particularly preferably less than or equal to 900 g / mol.

[0120] Furthermore, preferred compounds according to the invention are characterized by their sublimability. These compounds generally have a molecular weight of less than approximately 1200 g / mol.

[0121] Preferably, the compound may not comprise any alkoxy, thioalkoxy or hydroxy groups.

[0122] Furthermore, it can be provided that the compound according to formula (I) or a preferred embodiment of this compound is not in direct contact with a metal atom, preferably does not represent a ligand for a metal complex.

[0123] The above-mentioned preferred embodiments can be combined with each other as desired within the limitations defined in claim 1. In a particularly preferred embodiment of the invention, the above-mentioned advantages occur simultaneously.

[0124] Examples of preferred compounds according to the embodiments listed above are the compounds listed in the following table.

[0125]

[0126] The basic structure of the compounds of the invention can be prepared according to the methods outlined in the following schemes. The individual synthesis steps, such as coupling reactions leading to C–C and / or C–N bond formations, are known in principle to those skilled in the art. These include, among others, reactions according to BUCHWALD, SUZUKI, YAMAMOTO, STILLE, HECK, NEGISHI, SONOGASHIRA, and HIYAMA.

[0127] Further information on the synthesis of the compounds according to the invention can be found in the synthesis examples.

[0128] The following schemes describe the preparation of the compounds of the invention using explicit dibenzofuran compounds. This use is to be understood as an example, so that further compounds of the invention can be obtained via similar synthetic routes starting from other basic structures.

[0129] The compounds (3) according to the invention with L being an aromatic or heteroaromatic ring system can be prepared starting from the triflate- or halogen-functionalized 4,X-di-tert-alkyl-substituted dibenzofurans (1) known from the literature by CC coupling methods known to the person skilled in the art, preferably the Suzuki coupling, with boronic acids or esters (2) known from the literature, in the presence of a base, a palladium compound, a phosphine and a solvent or solvent mixture, see Scheme 1.

[0130] The compounds (6) according to the invention with direct attachment of the heterocycle (5) to the dibenzofuran can be prepared starting from the functionalized 4,X-di-tert-alkyl-substituted dibenzofuran boronic acids or esters (4) known from the literature by CC coupling methods known to the person skilled in the art, preferably the Suzuki coupling, in the presence of a base, a palladium compound, a phosphine and a solvent or solvent mixture, see Scheme 2.

[0131] Scheme 2: Schemes (1 ) and (2) are to be understood as examples, so that other groups RG are also suitable, as shown in the examples.

[0132] The meaning of the symbols used in the scheme presented above corresponds essentially to that defined for formula (I), although for reasons of clarity, numbering and a complete representation of all symbols have been omitted.

[0133] A further object of the present invention is therefore a process for preparing a compound according to the invention, wherein a dibenzofuran compound is synthesized and at least one nitrogen-containing heteroaromatic radical is introduced, preferably by means of a nucleophilic aromatic substitution reaction or a coupling reaction.

[0134] By these processes, optionally followed by purification, such as recrystallization or sublimation, the compounds according to the invention can be obtained in high purity, preferably more than 99% (determined by 1 H-NMR and / or HPLC).

[0135] The compounds of the invention can also be mixed with a polymer. It is also possible to covalently incorporate these compounds into a polymer. This is particularly possible with compounds substituted by reactive leaving groups, such as bromine, iodine, chlorine, boronic acid, or boronic acid esters, or by reactive, polymerizable groups, such as olefins or oxetanes. These can be used as monomers to produce corresponding oligomers, dendrimers, or polymers. The oligomerization or polymerization preferably takes place via the halogen functionality or the boronic acid functionality, or via the polymerizable group, respectively. It is also possible to crosslink the polymers via such groups. The compounds and polymers of the invention can be used as crosslinked or uncrosslinked layers.The invention therefore further provides oligomers, polymers or dendrimers comprising one or more of the above-listed structures of the formula (I) and preferred embodiments of this formula or compounds according to the invention, wherein one or more bonds of the compounds according to the invention or of the structures of the formula (I) and preferred embodiments of this formula to the polymer, oligomer or dendrimer are present. Depending on the linkage of the structures of the formula (I) and preferred embodiments of this formula or of the compounds, these therefore form a side chain of the oligomer or polymer or are linked in the main chain. The polymers, oligomers or dendrimers can be conjugated, partially conjugated or non-conjugated. The oligomers or polymers can be linear, branched or dendritic.The same preferences as described above apply to the repeating units of the compounds according to the invention in oligomers, dendrimers and polymers.

[0136] To prepare the oligomers or polymers, the monomers according to the invention are homopolymerized or copolymerized with other monomers. Copolymers are preferred, wherein the units according to formula (I) or the preferred embodiments described above and below are present in amounts of 0.01 to 99.9 mol%, preferably 5 to 90 mol%, particularly preferably 20 to 80 mol%. Suitable and preferred comonomers which form the polymer backbone are selected from fluorenes (e.g. according to EP 842208 or WO 2000 / 022026), spirobifluorenes (e.g. according to EP 707020, EP 894107 or WO 2006 / 061181), para-phenylenes (e.g. according to WO 92 / 18552), carbazoles (e.g. according to WO 2004 / 070772 or WO 2004 / 113468), thiophenes (e.g. according to EP 1028136), dihydrophenanthrenes (e.g. according to WO 2005 / 014689), cis- and trans-indenofluorenes (e.g. according to WO 2004 / 041901 or WO 2004 / 113412), ketones (e.g. according to WO 2005 / 040302), phenanthrenes (e.g.according to WO 2005 / 104264 or WO 2007 / 017066) or several of these units. The polymers, oligomers and dendrimers can contain further units, for example hole transport units, in particular those based on triarylamines, and / or electron transport units. Of particular interest are also compounds according to the invention which are characterized by a high glass transition temperature. In this context, particular preference is given to compounds according to the invention comprising structures according to the formula (I) or the preferred embodiments set out above and below which have a glass transition temperature of at least 70 °C, more preferably of at least 110 °C, most preferably of at least 125 °C and especially preferably of at least 150 °C, determined according to DIN 51005 (version 2005-08).

[0137] For processing the compounds of the invention from the liquid phase, for example by spin coating or printing processes, formulations of the compounds of the invention are required. These formulations can be, for example, solutions, dispersions, or emulsions. It may be preferred to use mixtures of two or more solvents for this purpose. Suitable and preferred solvents are, for example, toluene, anisole, o-, m- or p-xylene, methyl benzoate, mesitylene, tetralin, veratrole, THF, methyl-THF, THP, chlorobenzene, dioxane, phenoxytoluene, in particular 3-phenoxytoluene, (-)-fenchone, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, 1-methylnaphthalene, 2-methylbenzothiazole, 2-phenoxyethanol, 2-pyrrolidinone, 3-methylanisole, 4-methylanisole, 3,4-dimethylanisole, 3,5-dimethylanisole, acetophenone, a-terpineol, benzothiazole, butylbenzoate, cumene, cyclohexanol, cyclohexanone, Cyclohexylbenzene, decalin, dodecylbenzene, ethyl benzoate, indane, NMP,p-Cymene, phenetole, 1,4-diisopropylbenzene, dibenzyl ether, diethylene glycol butylmethyl ether, triethylene glycol butylmethyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, tripropylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 2-isopropylnaphthalene, pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene, 1,1-bis(3,4-dimethylphenyl)ethane, 2-methylbiphenyl, 3-methylbiphenyl, 1-methylnaphthalene, 1-ethylnaphthalene, ethyl octanoate, diethyl sebacate, octyloctanoate, heptylbenzene, menthyl isovalerate, cyclohexylhexanoate or mixtures of these solvents. The present invention therefore further provides a formulation or composition comprising at least one compound according to the invention and at least one further compound. The further compound can be, for example, a solvent,in particular, one of the above-mentioned solvents or a mixture of these solvents. If the further compound comprises a solvent, this mixture is referred to herein as a formulation. However, the further compound can also be at least one further organic or inorganic compound that is also used in the electronic device, for example an emitting compound and / or a further matrix material. Preferably, it can be provided that at least one further compound is selected from the group consisting of fluorescent emitters, phosphorescent emitters, emitters that exhibit TADF, host materials, electron-transport materials, electron-injection materials, hole-conductor materials, hole-injection materials, electron-blocking materials, and hole-blocking materials, preferably host materials.

[0138] The present invention further relates to the use of a compound according to the invention in an electronic device, in particular in an organic electroluminescent device. Preferably, the compounds according to the invention can be used in an electronic device as a host material, electron transport material, electron injection material, or hole blocking material.

[0139] The present invention further relates to an electronic device comprising at least one compound according to the invention. An electronic device within the meaning of the present invention is a device which contains at least one layer containing at least one organic compound. The component can also contain inorganic materials or layers composed entirely of inorganic materials. Particularly preferred is an electronic device selected from the group consisting of organic electroluminescent devices (OLEDs, sOLEDs, PLEDs, LECs, etc.), preferably organic light-emitting diodes (OLEDs), organic light-emitting diodes based on small molecules (sOLEDs), organic light-emitting diodes based on polymers (PLEDs), light-emitting electrochemical cells (LECs), organic laser diodes (O-lasers), organic plasmon emitting devices (DMKoller et al., Nature Photonics 2008, 1- 4); organic integrated circuits (O-ICs), organic field-effect transistors (O-FETs), organic thin-film transistors (O-TFTs), organic light-emitting transistors (O-LETs), organic solar cells (O-SCs), organic optical detectors, organic photoreceptors, organic field-quench devices (O-FQDs) and organic electrical sensors, preferably organic electroluminescent devices (OLEDs, sOLEDs, PLEDs, LECs, etc.), particularly preferably organic light-emitting diodes (OLEDs), organic light-emitting diodes based on small molecules (sOLEDs), organic light-emitting diodes based on polymers (PLEDs), in particular phosphorescent OLEDs.

[0140] The organic electroluminescent device contains a cathode, an anode, 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, for example, have an exciton-blocking function, may also be inserted between two emitting layers. It should be noted, however, that not all of these layers are necessarily present. The organic electroluminescent device may contain one emitting layer or it may contain multiple emitting layers.If multiple emission layers are present, they preferably have a total of multiple emission maxima between 380 nm and 750 nm, resulting in overall white emission. This means that different emitting compounds that can fluoresce or phosphoresce are used in the emitting layers. Systems with three emitting layers are particularly preferred, with the three layers exhibiting blue, green, and orange or red emission. The organic electroluminescent device according to the invention can also be a tandem electroluminescent device, particularly for white-emitting OLEDs.

[0141] The compound according to the invention can be used in different layers, depending on the precise structure. The compound according to the invention is preferably used as a host material, electron-transport material, electron-injection material, or hole-blocking material in an organic electroluminescent device. Preference is given to an organic electroluminescent device comprising a compound according to formula (I) or the preferred embodiments described above in an emitting layer as a matrix material for phosphorescent emitters or for emitters that exhibit TADF (thermally activated delayed fluorescence), in particular for phosphorescent emitters. Furthermore, preference is given to an organic electroluminescent device in which a compound according to the invention is contained in an electron-injection layer, in an electron-transport layer, and / or in a hole-blocking layer.The compound according to the invention is particularly preferably used as a matrix material for phosphorescent emitters, in particular for red, orange, blue, green or yellow, preferably for blue or green phosphorescent emitters, in an emitting layer.

[0142] Preferably, it can be provided that the organic electroluminescent device comprises at least one emission layer and at least one electron transport layer and the electron transport layer contains the compound according to the present invention.

[0143] If 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, within the meaning of this invention, is understood to mean luminescence from an excited state with higher spin multiplicity, i.e., a spin state > 1, in particular from an excited triplet state. For the purposes of this application, all luminescent complexes with transition metals or lanthanides, in particular all indium, platinum, and copper complexes, are to be considered phosphorescent compounds.

[0144] 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, 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.

[0145] In one embodiment of the invention, the compound according to the invention is used as the sole matrix material (“single host”) for emitters, preferably phosphorescent emitters.

[0146] A further 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 that 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, e.g., B. CBP (N,N-biscarbazolylbiphenyl) or those in WO 2005 / 039246, US 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 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 boronate 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, zinc complexes, e.g. according to EP 652273 or WO 2009 / 062578, diazasilole or tetraazasilole derivatives, e.g. according to WO 2010 / 054729, diazaphosphole derivatives, e.g. B. 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, dibenzofuran derivatives, e.g. according to WO 2015 / 169412, WO 2016 / 015810, WO 2016 / 023608, WO 2017 / 148564 or WO 2017 / 148565 or biscarbazoles, e.g. according to JP 3139321 B2.

[0147] Likewise, another phosphorescent emitter, which emits at a shorter wavelength than the actual emitter, can be present in the mixture as a co-host. Particularly good results are achieved when a red-phosphorescent emitter is used as the emitter and a yellow-phosphorescent emitter is used as the co-host in combination with the compound according to the invention.

[0148] Furthermore, a compound can be used as co-host which does not participate, or does not participate to a significant extent, in charge transport, as described, for example, in WO 2010 / 108579. In particular, compounds which have a large band gap and themselves do not participate, or at least do not participate to a significant extent, in the charge transport of the emitting layer are suitable as co-matrix material in combination with the compound according to the invention. Such materials are preferably pure hydrocarbons. Examples of such materials can be found, for example, in WO 2009 / 124627 or WO 2010 / 006680. In this context, it should be noted that compounds according to the invention without special functional groups, for example hole transport groups and / or electron transport groups, have advantageous properties.Particularly suitable phosphorescent compounds (= triplet emitters) are compounds that emit light upon suitable excitation, preferably in the visible range, and also contain at least one atom with an atomic number greater than 20, preferably greater than 38 and less than 84, particularly preferably greater than 56 and less than 80, in particular a metal with this atomic number. Compounds containing copper, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, iridium, palladium, platinum, silver, gold, or europium are preferably used as phosphorescent emitters, in particular compounds containing iridium or platinum.

[0149] Examples of the emitters described above can be found in the applications WO 00 / 70655, WO 2001 / 41512, WO 2002 / 02714, WO 2002 / 15645, EP 1191613, EP 1191612, EP 1191614, WO 05 / 033244, WO 05 / 019373, US 2005 / 0258742, WO 2009 / 146770, WO 2010 / 015307, WO 2010 / 031485, WO 2010 / 054731, WO 2010 / 054728, WO 2010 / 086089, WO 2010 / 099852, WO 2010 / 102709, WO 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 2015 / 117718, WO 2016 / 015815, WO 2016 / 124304, WO 2017 / 032439 and WO 2018 / 011186. In general, all phosphorescent complexes as used according to the prior art for phosphorescent electroluminescent devices and as known to the person skilled in the art in the field of organic electroluminescence are suitable, and the person skilled in the art can use further phosphorescent complexes without inventive step.

[0150] Examples of phosphorescent dopants are listed in the following table.

[0151]

[0152] The compounds of the invention are also particularly suitable as matrix materials for phosphorescent emitters in organic electroluminescent devices, as described, for example, in WO 98 / 24271, US 2011 / 0248247, and US 2012 / 0223633. In these multi-color display components, an additional blue emission layer is vapor-deposited over the entire surface of all pixels, even those with a color other than blue.

[0153] In a further embodiment of the invention, the organic electroluminescent device according to the invention does not contain a separate hole injection layer and / or hole transport layer and / or hole blocking layer and / or electron transport layer, i.e. the emitting layer directly adjoins the hole injection layer or the anode, and / or the emitting layer directly adjoins the electron transport layer or the electron injection layer or the cathode, as described, for example, in WO 2005 / 053051. Furthermore, it is possible to use a metal complex that is the same as or similar to the metal complex in the emitting layer as a hole transport or hole injection material directly adjacent to the emitting layer, as described, for example, in WO 2009 / 030981.

[0154] In the further layers of the organic electroluminescent device according to the invention, all materials commonly used in the prior art can be used. Therefore, the skilled person can, without inventive step, use all materials known for organic electroluminescent devices in combination with the compounds according to formula (I) according to the invention or the preferred embodiments described above.

[0155] Also preferred is an organic electroluminescent device, characterized in that one or more layers are coated using a sublimation process. The materials are sublimated 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 that the initial pressure is even lower, for example less than 10' 7 mbar.

[0156] Also preferred is an organic electroluminescent device, characterized in that one or more layers are coated using the OVPD (Organic Vapor Phase Deposition) process or by means of carrier gas sublimation. The materials are sublimated at a pressure between 10' 5mbar and 1 bar. A special case of this process is the OVJP (Organic Vapor Jet Printing) process, in which the materials are applied directly through a nozzle and thus structured. Also preferred is an organic electroluminescent device, characterized in that one or more layers are produced from solution, for example by spin coating, or using any printing process, such as screen printing, flexographic printing, offset printing, LITI (Light Induced Thermal Imaging, thermal transfer printing), inkjet printing, or nozzle printing. Soluble compounds are required for this, which can be obtained, for example, by suitable substitution.

[0157] Formulations for applying a compound according to formula (I) or the preferred embodiments thereof described above are novel. The present invention therefore further provides formulations comprising at least one solvent and a compound according to formula (I) or the preferred embodiments thereof described above.

[0158] Furthermore, hybrid processes are possible, in which, for example, one or more layers are applied from solution and one or more further layers are vapor-deposited.

[0159] These processes are generally known to the person skilled in the art and can be applied by him without inventive step to organic electroluminescent devices containing the compounds according to the invention.

[0160] The compounds of the invention and the organic electroluminescent devices of the invention are distinguished from the prior art in particular by a low refractive index (RI). Furthermore, these compounds and the organic electroluminescent devices obtainable therefrom exhibit an improved lifetime. The other electronic properties of the electroluminescent devices, such as efficiency or operating voltage, remain at least equally good. In a further variant, the compounds of the invention and the organic electroluminescent devices of the invention are distinguished from the prior art in particular by improved efficiency and / or operating voltage and a longer lifetime.

[0161] The electronic devices according to the invention, in particular organic electroluminescent devices, are characterized by one or more of the following surprising advantages over the prior art:

[0162] 1. Electronic devices, in particular organic electroluminescent devices containing compounds of formula (I) or the preferred embodiments described above and below, in particular as matrix material or as electron-conducting materials, exhibit excellent efficiency. Compounds of the invention according to formula (I) or the preferred embodiments described above and below achieve a low operating voltage when used in electronic devices.

[0163] 2. Electronic devices, in particular organic electroluminescent devices containing compounds according to formula (I) or the preferred embodiments described above and below, in particular as matrix material or as electron-conducting materials, exhibit a very long lifetime. These compounds, in particular, result in low roll-off, i.e., a low drop in the power efficiency of the device at high luminance levels.

[0164] 3. The compounds according to the invention according to formula (I) or the preferred embodiments described above and below show a very high stability and lifetime.

[0165] 4. Electronic devices, in particular organic electroluminescent devices containing compounds according to formula (I) or the preferred embodiments described above and below, in particular as matrix material or as electron-conducting materials, have a very low refractive indices.

[0166] 5. Using compounds according to formula (I) or the preferred embodiments described above and below, the formation of optical loss channels can be avoided in electronic devices, particularly organic electroluminescent devices. As a result, these devices are characterized by high PL and thus high EL efficiency of emitters and excellent energy transfer from the matrices to dopants.

[0167] 6. Compounds according to formula (I) or the preferred embodiments described above and below have excellent glass film formation.

[0168] 7. Compounds according to formula (I) or the preferred embodiments described above and below form very good films from solutions.

[0169] These advantages mentioned above are not accompanied by an excessive deterioration of the other electronic properties.

[0170] It should be noted that variations of the embodiments described in the present invention fall within the scope of this invention. Any feature disclosed in the present invention may, unless explicitly excluded, be replaced by alternative features serving the same, equivalent, or similar purpose. Thus, unless otherwise stated, any feature disclosed in the present invention is to be considered an example of a generic series or an equivalent or similar feature.

[0171] All features of the present invention may be combined with each other in any way, unless certain features and / or steps are mutually exclusive. This applies in particular to preferred features of the present invention. Likewise, features of non-essential combinations may be used separately (and not in combination).

[0172] It should further be noted that many of the features, and in particular those of the preferred embodiments of the present invention, are inventive in their own right and should not be considered merely part of the embodiments of the present invention. Independent protection may be sought for these features in addition to or alternatively to any presently claimed invention.

[0173] The teaching of technical action disclosed in the present invention can be abstracted and combined with other examples.

[0174] The invention is further illustrated by the following examples, without intending to limit it. From these descriptions, one skilled in the art can practice the invention within the entire disclosed scope and, without inventive step, prepare further compounds according to the invention and use them in electronic devices or apply the method according to the invention.

[0175] Examples:

[0176] Unless otherwise stated, the following syntheses were carried out under a protective gas atmosphere in dried solvents. The solvents and reagents can be purchased from Sigma-Aldrich or ABCR, for example. The respective information in square brackets or the numbers given for individual compounds refer to the CAS numbers of the known compounds. For compounds that can exhibit multiple isomeric, enantiomeric, diastereomeric, or tautomeric forms, one form is shown as a representative example.

[0177] A: Synthons known from literature S:

[0178] B: Representation of the synthons S:

[0179] Example S1 :

[0180] Procedure analogous to M. Tashiro et al., J. Org. Chem., 1982, 47 (23), 4426, compound 28. Preparation: 36.7 g (100 mmol) LS1, 19.0 ml (200 mmol) BBrs. Yield: 26.2 g (75 mmol) 75%; Purity: 97% n. 1 H-NMR.

[0181] 2) S1 :

[0182] Procedure analogous to S. Hu et al., J. Mol. Struct., 2023, 1286, 135565, compound 1o. Batch: 35.3 g (100 mmol) S1a. Recrystallization of the crude product from acetonitrile. Yield: 37.3 g (77 mmol) 77%; Purity: 98% n. 1 H-NMR.

[0183] The following connections can be represented analogously.

[0184] A well-stirred mixture of 48.5 g (100 mmol) S1, 50.8 g (200 mmol) bis(pinacolato)diborane [73183-34-3], 29.5 g (300 mmol) potassium acetate, anhydrous [127-08-2], 200 g glass beads (3 mm diameter), 3.7 g (5 mmol) bis(tncyclohexylphosphino)palladium(II) chloride [29934-17-6] and 1500 ml dioxane is stirred for 18 h at 100 °C. The mixture is filtered while still warm through a bed of Celite pre-slurried with dioxane, the filtrate is concentrated in vacuo, the residue is taken up in 500 ml of dichloromethane (DCM), the organic phase is washed twice with 300 ml of water and once with 200 ml of saturated sodium chloride solution, and dried over magnesium sulfate. The mixture is filtered with suction through a bed of silica gel pre-slurried with DCM, the filtrate is concentrated to dryness, the oil is crystallized by adding 50 ml of acetonitrile and 100 ml of ethanol, filtered with suction, dried, and chromatographed (Torrent column chromatography machine from Semrau). Yield: 37.3 g (80 mmol) 80%; Purity: approximately 97% pure. 1 H-NMR.

[0185] The following connections can be represented analogously.

[0186]

[0187] A well-stirred mixture of 48.5 g (100 mmol) S1, 47.9 g (110 mmol) 4,6-diphenyl-2-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]-1,3,5-triazine [1313018-07-3], 46.1 g (200 mmol) tripotassium phosphate monohydrate, 1.16 g (1 mmol) tetrakis-triphenylphosphinopalladium(O), 500 ml dimethyl sulfoxide (DMSO) and 100 g glass beads (3 mm diameter) is stirred for 16 h at 80 °C. After complete conversion, the mixture is allowed to cool, decanted from the glass beads, and the DMSO is largely removed under vacuum. The residue is treated with 300 ml of methanol and 300 ml of water, the crude product is filtered off, washed twice with 200 ml of water and twice with 200 ml of methanol, and dried under vacuum. The crude product is taken up in 500 ml of DCM, filtered through a bed of Celite pre-slurried with DCM, the filtrate is concentrated to dryness, the residue is stirred hot with 200 ml of methanol, the crude product is filtered off, washed twice with 50 ml of methanol each time, and dried under vacuum.Further purification is achieved 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: 44.4 g (69 mmol) 69%; Purity: approximately 99.9% by HPLC. Alternatively, or when chlorides are used, the Suzuki coupling can be carried out in the system toluene / dioxane / water (4:1:5 vvv) with 1 mmol palladium(II) acetate and 2 mmol S-Phos or X-Phos.

[0188]

[0189] A mixture of 46.3 g (100 mmol) of S100, 26.8 g (100 mmol) of 2-chloro-4,6-diphenyl-1,3,5-triazine [3842-55-5], 42.5 g (200 mmol) of tripotassium phosphate, 860 mg (2 mmol) of S-Phos, 225 mg (1 mmol) of palladium(II) acetate, 400 ml of toluene, 100 ml of dioxane, and 300 ml of water is heated under reflux for 16 h. After cooling, the organic phase is separated, washed twice with 200 ml of water each time, once with 200 ml of saturated sodium chloride solution, and dried over magnesium sulfate. The drying agent is filtered off through a bed of Celite pre-slurried with toluene, the filtrate is concentrated to dryness, the residue is stirred with 200 ml of hot methanol, filtered, and dried in vacuo. 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: 41.6 g (73 mmol), 73%. Purity: 99.9% by HPLC.

[0190]

[0191] Example: Production of OLEDs

[0192] The production of OLEDs according to the invention as well as OLEDs according to the prior art is carried out according to a general process according to WO 2004 / 058911 , which is adapted to the conditions described here (layer thickness variation, materials used).

[0193] The following examples present the results of various OLEDs. Cleaned glass plates (cleaned in a Miele laboratory dishwasher, using Merck Extran cleaner) coated with 50 nm thick structured ITO (indium tin oxide) are pretreated with UV ozone for 25 minutes (UV ozone generator PR-100, UVP). These coated glass plates form the substrates onto which the OLEDs are applied. a) Blue Fluorescence OLED Devices - BF:

[0194] The compounds B according to the invention can be used in the hole-blocking layer (HBL) and the electron-transport layer (ETL). All materials are thermally vapor-deposited 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 (dopant, emitter) D, which is admixed to the matrix material(s) by co-evaporation in a specific volume fraction. A specification such as SMB:D (97%:3%) means that the SMB material is present in the layer in a volume fraction of 97% and the dopant D in a volume fraction of 3%. Analogously, 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 or refer to the previously presented synthesis examples.

[0195] The OLEDs are characterized as standard. For this purpose, the electroluminescence spectra, current efficiency (measured in cd / A), power efficiency (measured in λ / W), and external quantum efficiency (EQE, measured in percent) are determined as a function of luminance, calculated from current-voltage-luminance (IUL) curves assuming a Lambertian radiation pattern. The EQE (%) and voltage (V) are expressed at a luminance of 1000 cd / m². 2

[0196] The OLEDs have the following layer structure:

[0197] Substrat

[0198] Hole injection layer (HIL) made of HTM1 doped with 5% NDP-9 (commercially available from Novaled), 20 nm

[0199] Hole transport layer (HTL), made of HTM1, 180 nm

[0200] Electron blocking layer (EBL), see Table 1

[0201] Emission layer (EML), see Table 1 Hole blocking layer (HBL), see Table 1

[0202] Electron transport layer (ETL), see Table 1

[0203] Electron injection layer (EIL) made of ETM2, 1 nm

[0204] Cathode made of aluminum, 100 nm

[0205] Table 1 : Structure of blue fluorescent OLED device

[0206] Table 2: Results of blue fluorescent OLED devices b) Phosphorescent OLED components:

[0207] The compounds B according to the invention can be used in the hole-blocking layer (HBL), the electron-transport layer (ETL), and in the emission layer (EML) as electron-conducting matrix material (host material) (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 admixed 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 the material M1 is present in the layer in a volume fraction of 55%, M2 in a volume fraction of 35%, and Ir in a volume fraction of 10%. Analogously, 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 fabricate the OLEDs are shown in Table 5 or refer to the synthesis examples presented previously.

[0208] The OLEDs are characterized as standard. For this purpose, the electroluminescence spectra, current efficiency (measured in cd / A), power efficiency (measured in λ / W), and external quantum efficiency (EQE, measured in percent) are determined as a function of luminance, calculated from current-voltage-luminance (IUL) curves assuming a Lambertian radiation pattern. The EQE (%) and voltage (V) are expressed at a luminance of 1000 cd / m². 2

[0209] The OLEDs have the following layer structure:

[0210] Substrat

[0211] Hole injection layer (HIL) made of HTM1 doped with 5% NDP-9 (commercially available from Novaled), 20 nm

[0212] 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

[0213] Emission layer (EML), see Table 3

[0214] Hole blocking layer (HBL), see Table 3

[0215] Electron transport layer (ETL), see Table 3

[0216] Electron injection layer (EIL) made of ETM2, 1 nm

[0217] Cathode made of aluminum, 100 nm

[0218] Table 3: Structure of phosphorescent OLED components

[0219] Table 4: Results of phosphorescent OLED devices

[0220] Table 5: Structural formulas of the materials used

Claims

Patent claims 1. Compound according to formula (I), Formula (I) where the group Q is selected from structures of the formula (Q-1 ), Formula (Q-1 ) where the dashed bond represents the bond to the group L or, in case q= 0, to the dibenzofuran skeleton according to formula (I), s 1 , 2 or 3, where in case q=0 the index s is 1, and for the other symbols: X is the same or different at each occurrence N or CR C , where at least one of the groups X is N; X a is the same or different at each occurrence N, CR a or, in the event that at this point this group binds to another group, C, where at most two of the groups X a per ring represents N; X b is the same or different at each occurrence N, CR b or, in the event that at this point this group is transferred to another group, C, where at most two of the groups X b per ring represents N; L is, at each occurrence, identically or differently, a bivalent, trivalent or tetravalent aromatic or heteroaromatic ring system having 6 to 40 aromatic ring atoms, each of which is substituted by one or more radicals R d may be substituted other than H; q is 0 or 1, where q = 0 means that the group L is not present and that the group Q is directly bonded to the corresponding atom, for example a carbon atom, of the dibenzofuran basic structure according to formula (I); R is, identically or differently at each occurrence, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 10 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 10 C atoms, each of which is substituted by one or more radicals R 2 may be substituted by other than H, each of which may be substituted by one or more radicals R 2may be substituted other than H, where two or more substituents R may form a ring; R a , R b is, at each occurrence, the same or different: H, D, OH, F, CI, Br, I, CN, NO2, N(Ar)2, N(R C )2, C(=O)N(Ar)2, C(=O)N(R c )2, C(Ar)3, C(R C )3, Si(Ar)3, Si(R c )3, Ge(Ar)3, Ge(R c )3, B(Ar)2, B(R C )2, C(=O)Ar, C(=O)R C , P(=O)(Ar)2, P(=O)( R c )2, P(Ar)2, P(R C )2, S(=O)Ar, S(=O)R C , S(=O)2Ar, S(=O)2R C , OSO2Ar, OSO2R C , a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms or an alkenyl or alkynyl group having 2 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 C atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl or alkynyl group is each substituted by one or more radicals R cmay be substituted by other than H, where one or more non-adjacent CH2 groups are substituted by R c C=CR c , C^C, Si(R c )2, C=O, C=S, C=Se, C=NR C , -C(=O)O-, -C(=O)NR C -, NR C , P(=O)(R C ), -O-, -S-, SO or SO2, or an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, each of which is substituted by one or more radicals R c may be substituted by other than H, or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R c can be substituted, two radicals R a , R b also with each other or a residue R a , R b with another group, in particular a residue R c form a ring; Ar is, at each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, which is substituted by one or more radicals R c may be substituted other than H, where the group Ar, in the case that X is CR C is, with the remainder R c the group X can form a ring; R c , R d is, at each occurrence, the same or different: H, D, OH, F, CI, Br, I, CN, NO2, N(Ar')2, N(R 1 )2, C(=O)N(Ar')2, C(=O)N(R 1 )2, C(Ar')3, C(R 1 )3, Si(Ar')3, Si(R 1 )3, Ge(Ar')3, Ge(R 1 )3, B(Ar')2, B(R 1 )2, C(=O)Ar', C(=O)R 1 , P(=O)(Ar')2, P(=O)(R 1 )2, P(Ar')2, P(R 1 )2, S(=O)Ar', S(=O)R 1 , S(=O)2Ar', S(=O)2R 1 , OSO2Ar', OSO2R 1, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms or an alkenyl or alkynyl group having 2 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 C atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl or alkynyl group is each substituted with one or more radicals R 1 may be substituted by other than H, where one or more non-adjacent CH2 groups are substituted by R 1 C=CR 1 , C=C, Si(R 1 )2, C=O, C=S, C=Se, C=NR 1 , -C(=O)O-, -C(=O)NR 1 -, NR 1 , P(=O)(R 1 ), -O-, -S-, SO or SO2, or an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, each of which is substituted by one or more radicals R 1 may be substituted by other than H, or a Aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which are substituted by one or more radicals R 1may be substituted by other than H, two residues may be selected from the groups R c , R d also with each other or a residue R c or R d with another group, in particular a residue R a or R b form a ring; Ar' is at each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, which is substituted with one or more radicals R 1 may be substituted by other than H, whereby two radicals Ar' which are bonded to the same C-atom, Si-atom, N-atom, P-atom or B-atom may also be bonded by a single bond or a bridge selected from B(R 1 ), C(R 1 )2, Si(R 1 )2, C=O, C=NR 1 , C=C(R 1 )2, O, S, S=O, SO2, N(R 1 ), P(R 1 ) and P(=O)R 1 , be bridged together; R 1is, at each occurrence, the same or different: H, D, F, CI, Br, I, CN, NO2, N(Ar”)2, N(R 2 )2, C(=O)Ar”, C(=O)R 2 , P(=O)(Ar”)2, P(Ar”)2, B(Ar”)2, B(R 2 )2, C(Ar”)3, C(R 2 )3, Si(Ar”)3, Si(R 2 )3, Ge(Ar”)3, Ge(R 2 )3, a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 C atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 40 C atoms or an alkenyl group having 2 to 40 C atoms, each of which is substituted by one or more radicals R 2 may be substituted by other than H, where one or more non-adjacent CH2 groups are substituted by -R 2 C=CR 2 -, -C=C-, Si(R 2 )2, C=O, C=S, C=Se, C=NR 2 , -C(=O)O-, -C(=O)NR 2 -, NR 2 , P(=O)(R 2), -O-, -S-, SO or SO2 and where one or more H atoms can be replaced by D, F, CI, Br, I, CN or NO2, or an aromatic or heteroaromatic ring system with 5 to 60 aromatic ring atoms, each of which is substituted by one or more radicals R 2 may be substituted, or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms, which may be substituted by one or more radicals R 2 can be substituted, or an aralkyl or heteroaralkyl group having 5 to 60 aromatic ring atoms which may be substituted by one or more radicals R 2 may be substituted by other than H, or a combination of these systems; two or more radicals R 1 form a ring with each other, whereby one or more radicals R 1 form a ring with another part of the compound; Ar” is at each occurrence, identically or differently, an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, which is substituted by one or more radicals R 2 may be substituted, whereby two radicals Ar” which bind to the same C-atom, Si-atom, N-atom, P-atom or B-atom can also be linked by a single bond or a bridge selected from B(R 2 ), C(R 2 )2, Si(R 2 )2, C=O, C=NR 2 , C=C(R 2 )2, O, S, S=O, SO2, N(R 2 ), P(R 2 ) and P(=O)R 2 , be bridged together; R 2is selected, identically or differently at each occurrence, from the group consisting of H, D, F, CN, an aliphatic hydrocarbon radical having 1 to 20 C atoms or an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, in which one or more H atoms may be replaced by D, F, CI, Br, I or CN and which may be substituted by one or more alkyl groups each having 1 to 4 carbon atoms, where two or more substituents R 2 form a ring with each other.

2. A compound according to claim 1, characterized in that the compound corresponds to the following formula (Ha), (Hb), (Hc) or (Hd), where the symbols R, Q, L, q, s, R a , R b and R c have the meanings given in claim 1 and j is 2 or 3, i is 1 or 2 and k is 0 or 1, the sum of both being 5, the sum of both i being 3 and the sum of j and k being 3.

3. A compound according to claim 1 or 2, characterized in that the group Q in formula (L) q -(Q) s is selected from structures of formulas (Q-2) to (Q-16), Formula (Q-14) Formula (Q-15) Formula (Q-16) where the dashed bond represents the bond to the group L or, in case q= 0, to the dibenzofuran skeleton according to formula (I) and the symbols R c and Ar have the meanings given in claim 1 and the following applies to the other symbols: X c is the same or different at each occurrence N or CR C , where at most two of the groups X c per ring represents N; Y c is chosen from C(R C )2, Si(R c )2, Ge(R c )2, NR C , 0 or S.

4. Compound according to one or more of claims 1 to 3, characterized in that at least one radical Ar in formulas (Q-1) to (Q-16) is selected from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthalene, indole, benzofuran, benzothiophene, carbazole, benzimidazolobenzimidazole, dibenzofuran, dibenzothiophene, indenocarbazole, indolocarbazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, isoquinoline, quinazoline, quinoxaline, phenanthrene or triphenylene, which are each substituted with one or more radicals R c may be substituted by other than H.

5. A compound according to one or more of claims 1 to 4, characterized in that the compound corresponds to at least one of the following formulas (III-1) to (III-27) where the symbols R, Q, L, q, s, R a , R b and R chave the meanings given in claim 1 and j is 2 or 3.

6. Compound according to one or more of claims 1 to 5, characterized in that the radical L is selected on each occurrence, identically or differently, from divalent, trivalent or tetravalent phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthalene, indole, benzofuran, benzothiophene, carbazole, benzimidazolobenzimidazole, dibenzofuran, dibenzothiophene, indenocarbazole, indolocarbazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, isoquinoline, quinazoline, quinoxaline, phenanthrene or triphenylene, which are each substituted with one or more radicals R d may be substituted by other than H.

7. Compound according to one or more of claims 1 to 6, characterized in that in formula (I), (IIa), (IIIb), (IIIc), (IIId) or (III-1) to (III-27) the group Q corresponds to the formula (Q-2), the index s is 1 and the index q is 0, wherein at least one of the radicals Ar in formula is selected from phenyl, biphenyl, dibenzofuran, which are each substituted with one or more radicals R c may be substituted other than H; or that in formula (I), (IIa), (IIb), (IIc), (IId) or (III-1) to (III-27) the group Q corresponds to the formula (Q-3), (Q-11), (Q-12) or (Q-13), the index s is 1 and the index q is 0, where at least one of the radicals Ar in formula is selected from phenyl, biphenyl, dibenzofuran, which are each substituted with one or more radicals R cmay be substituted other than H; or that in formula (I), (IIa), (IIb), (IIc), (IId) or (III-1) to (III-27) the group Q corresponds to the formula (Q-7), (Q-14), (Q-15) or (Q-16), the index s is 1 and the index q is 0, where at least one of the radicals Ar in formula is selected from phenyl, biphenyl, dibenzofuran, which are each substituted with one or more radicals R c may be substituted by other than H.

8. Compound according to one or more of claims 1 to 6, characterized in that in formula (I), (Ha), (Hb), (Hc), (Hd) or (III-1) to (III-27) the group Q corresponds to the formula (Q-2), the index s is 1 and the index q is 1, wherein the group L is selected from divalent phenyl, biphenyl, dibenzofuran, carbazole, which are each substituted with one or more radicals R d may be substituted by other than H, where at least one of the radicals Ar in formula is selected from phenyl, biphenyl, dibenzofuran, each of which is substituted by one or more radicals Rc may be substituted other than H; or that in formula (I), (IIa), (IIb), (IIc), (IId) or (III-1) to (III-27) the group Q corresponds to the formula (Q-3), (Q-11), (Q-12) or (Q-13), the index s is 1 and the index q is 1, where the group L is selected from divalent phenyl, biphenyl, dibenzofuran, carbazole, which are each substituted with one or more radicals R d may be substituted by other than H, where at least one of the radicals Ar in formula is selected from phenyl, biphenyl, dibenzofuran, each of which is substituted by one or more radicals R c may be substituted other than H; or that in formula (I), (IIa), (IIb), (IIc), (IId) or (III-1) to (III-27) the group Q corresponds to the formula (Q-7), (Q-14), (Q-15) or (Q-16), the index s is 1 and the index q is 1, wherein the group L is selected from divalent phenyl, biphenyl, dibenzofuran, carbazole, which are each substituted with one or more radicals R dmay be substituted by other than H, where at least one of the radicals Ar in formula is selected from phenyl, biphenyl, dibenzofuran, each of which is substituted by one or more radicals R c may be substituted by other than H.

9. A compound according to one or more of claims 1 to 8, characterized in that the group -(L) q - in formula -(L) q -(Q) S a structure of the formula -(L d )0-, so that the group of the formula -(L) q -(Q) S is selected from structures of the formula -(L d )0-(Q)s, where the index o is 0, 1 , 2, 3, 4 or 5, where o = 0 means that the group L d is not present and that the group Q is directly bound to the corresponding atom, for example a carbon atom, of the Dibenzofuran skeleton according to formula (I), and the residue L d is chosen from structures of the formulas (L d -1 ) to (L d -13) where the dashed bonds represent the attachment points and the other symbols are: X d is the same or different at each occurrence N, CR d or, in the event that at this point this group binds to another group, C, where at most three of the groups X d per ring represent N, where R d has the meaning given in claim 1; Y d is chosen from C(R d )2, NR d , 0 or S; where the structure of the formula -(L d )0- for the index s =1 in formula -( L d )o-(Q)s is bivalent, for s=2 trivalent and for s=3 tetravalent.

10. A compound according to claim 9, characterized in that the group L d is chosen from structures of the formulas (L d -14) to (L d -33). where the dashed bonds represent the attachment points, the symbol Rd has the meaning given in claim 1, the symbol X d has the meaning given in claim 9 and the following applies to the other symbols: i is 1 or 2; and j is 0, 1 or 2.

11. A compound according to one or more of claims 1 to 10, characterized in that the compound corresponds to one of the following formulas (IV-1) to (IV-4), where the symbols R, X, X a , X b and Ar have the meanings given in claim 1, the symbols X d and Y d have the meanings given in claim 9.

12. A compound according to one or more of claims 1 to 11, characterized in that the compound corresponds to one of the following formulas (V-1) to (V-37), where the symbols R, R a , R b , R c, R d and Ar have the meanings given in claim 1, the symbol Y d have the meanings given in claim 9 and the further symbols have the following meaning: n is 2 or 3.

13. A compound according to at least one of the preceding claims, characterized in that the group R stands for methyl, ethyl, propyl, or three groups R which bond to the same C atom form a bi- or tricycloalkyl radical having 9 or 10 carbon atoms, it being possible for these groups to be deuterated.

14. A formulation comprising at least one compound according to one or more of claims 1 to 13 and at least one further compound, wherein the further compound is preferably selected from one or more solvents.

15. A composition comprising at least one compound according to one or more of claims 1 to 13 and at least one further compound selected from the group consisting of fluorescent emitters, phosphorescent emitters, emitters exhibiting TADF, host materials, electron transport materials, electron injection materials, hole conductor materials, hole injection materials, electron blocking materials and hole blocking materials.

16. A process for preparing a compound according to one or more of claims 1 to 13, characterized in that a dibenzofuran compound is synthesized and at least one nitrogen-containing heteroaromatic radical is introduced, preferably by means of a nucleophilic aromatic substitution reaction or a coupling reaction.

17. Use of a compound according to one or more of claims 1 to 13 or an oligomer, polymer in an electronic device, preferably as host material, hole conductor material, hole injection material or electron blocking material.

18. Electronic device comprising at least one compound according to one or more of claims 1 to 13.

19. Electronic device according to claim 18, which is an organic electroluminescent device, characterized in that the organic electroluminescent device comprises at least one emission layer and at least one electron transport layer and the electron transport layer contains the compound according to one or more of claims 1 to 13.

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