Materials for organic electroluminescent devices

Abstract

The present invention relates to dibenzofuran derivatives substituted by electron-deficient heteroaryl groups and to electronic devices, especially organic electroluminescent devices, containing these compounds as triplet matrix materials.

Description

[Technical field]

[0001] The present invention describes dibenzofuran and dibenzothiophene derivatives substituted with electron-deficient heteroaromatic systems and electronic devices comprising these compounds, in particular organic electroluminescent devices comprising these compounds as triplet matrix materials.

[0002] Phosphorescent organometallic complexes are often used in organic electroluminescent devices (OLEDs). In general, there is still a need for improvements in OLEDs. The properties of phosphorescent OLEDs are not determined solely by the triplet emitter used. More specifically, other materials used, such as matrix materials, are also particularly important here. Therefore, improvements in these materials can also lead to clear improvements in OLED properties.

[0003] According to the prior art, carbazole derivatives and dibenzofuran derivatives, especially those substituted with electron-deficient heteroaromatic systems, such as triazines, are among the matrix materials used in phosphorescent emitters, as disclosed, for example, in WO 2015 / 169412. In general, there is still a need to improve the solubility and lifetime of these material classes, especially when they need to be processed from solution. Therefore, it is an object of the present invention to provide compounds that have good processability from solution and provide improved lifetime as matrix materials in phosphorescent OLEDs manufactured from solution.

[0004] Surprisingly, it has been found that organic electroluminescent devices comprising compounds of formula (1) below, when used as matrix materials for phosphorescent dopants, have high solubility and high glass transition temperatures, resulting in very good processability from solution and improved lifetimes compared to the prior art.

[0005] Thus, the present invention provides a compound of formula (1)

[0006] [ka]

[0007] (wherein the symbols and subscripts used are as follows: Y 1 is the same or different in each occurrence and is O or S; Y 2 are the same or different in each case, and NAr 2 , O, S or CR2; Z, at each occurrence, is the same or different, and is CR or N, with the proviso that at least two Z are N; Ar 1 , Ar 2 is the same or different in each occurrence and is an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, optionally substituted by one or more R radicals; R is the same or different in each occurrence and is H, D, F, Cl, Br, I, N(Ar'), N(R 1 )2, OAr', SAr', CN, NO2, OR 1 , S.R. 1 , COOR 1 , C(=O)N(R 1 )2, Si(R 1 )3, B(OR 1 )2, C(=O)R 1 , P(=O)(R 1 )2, S(=O)R 1 , S(=O)2R 1 , OSO2R 1 , a linear alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms, or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group is in each case composed of one or more R 1 radicals) (wherein one or more non-adjacent CH groups are optionally substituted by Si(R 1)2, C=O, NR 1 , O, S or CONR 1 or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms, preferably 5 to 40 aromatic ring atoms, in each case one or more R 1 at the same time, the two R radicals may also together form a ring system; Ar', in each occurrence, is the same or different, and is an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, and one or more R 1 At the same time, two Ar′ radicals attached to the same nitrogen atom may also be substituted by a single bond or an N(R 1 ), C(R 1 ) 2, may be crosslinked to each other by bridges selected from O and S; R 1 are the same or different in each case and are H, D, F, Cl, Br, I, N(R 2 )2, CN, NO2, OR 2 , S.R. 2 , Si(R 2 )3, B(OR 2 )2, C(=O)R 2 , P(=O)(R 2 )2, S(=O)R 2 , S(=O)2R 2 , OSO2R 2 , a linear alkyl group having 1 to 20 carbon atoms, or an alkenyl or alkynyl group having 2 to 20 carbon atoms, or a branched or cyclic alkyl group having 3 to 20 carbon atoms, wherein the alkyl, alkenyl or alkynyl group is each selected from the group consisting of one or more R 2 radicals) (wherein one or more non-adjacent CH groups are optionally substituted with Si(R 2 )2, C=O, NR 2 , O, S or CONR 2wherein one or more hydrogen atoms in the alkyl, alkenyl or alkynyl group may be replaced by D, F, Cl, Br, I or CN), or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, in each case one or more R 2 At the same time, two or more R 1 the radicals together may form an aliphatic ring system; R 2 are in each occurrence the same or different and are H, D, F, CN or an aliphatic, aromatic or heteroaromatic organic radical having 1 to 20 carbon atoms, in particular a hydrocarbyl radical, in which one or more hydrogen atoms may also be replaced by F; p, q, r, in each occurrence, are the same or different and are 0, 1, 2 or 3; s is the same or different in each occurrence and is 0, 1, 2, 3 or 4. to provide.

[0008] An aryl group in the context of the present invention contains 6 to 40 carbon atoms; a heteroaryl group in the context of the present invention contains 2 to 40 carbon atoms and at least one heteroatom, with the sum of carbon atoms and heteroatoms being at least 5. The heteroatoms are preferably selected from N, O and / or S. An aryl or heteroaryl group is understood herein to mean either a simple aromatic ring, i.e. benzene, or a simple heteroaromatic ring, such as pyridine, pyrimidine, thiophene, etc., or a condensed (condensed ring) aryl or heteroaryl group, such as naphthalene, anthracene, phenanthrene, quinoline, isoquinoline, etc. Aromatic systems linked together by a single bond, such as biphenyl, on the other hand, are not called aryl or heteroaryl groups, but aromatic ring systems.

[0009] Aromatic ring systems in the context of the present invention contain 6 to 40 carbon atoms in the ring system. Heteroaromatic ring systems in the context of the present invention contain 2 to 39 carbon atoms in the ring system and at least one heteroatom, with the sum of carbon atoms and heteroatoms being at least 5. The heteroatoms are preferably selected from N, O and / or S. Aromatic or heteroaromatic ring systems in the context of the present invention are understood to mean systems which do not necessarily contain only aryl or heteroaryl groups, but in which two or more aryl or heteroaryl groups can also be linked by non-aromatic units, such as carbon, nitrogen or oxygen atoms. They are also understood to mean systems in which two or more aryl or heteroaryl groups, such as biphenyl, terphenyl, bipyridine or phenylpyridine, are directly linked to each other. For example, systems such as fluorene, 9,9'-spirobifluorene, 9,9'-diarylfluorene, triarylamines, diaryl ethers, stilbenes, etc. are also considered to be aromatic ring systems in the context of the present invention, as are systems in which two or more aryl groups are linked, for example by short alkyl groups. 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 bonded to one another, such as biphenyl or bipyridine, and also fluorene or spirobifluorene.

[0010] In the context of the present invention, the term "alkyl group" is used as a general term for straight-chain, branched or cyclic alkyl groups. Similarly, the terms "alkenyl group" and "alkynyl group" are used as a general term for both straight-chain and branched cyclic alkenyl and alkynyl groups, respectively.

[0011] In the context of the present invention, the aliphatic hydrocarbyl radical or alkyl group or alkenyl or alkynyl group, which may contain 1 to 40 carbon atoms and in which the individual hydrogen atoms or CH2 groups may be replaced by the abovementioned groups, is preferably methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl, neopentyl, cyclopentyl, n-hexyl, neohexyl, cyclo ... 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, pentynyl, hexynyl, heptynyl or octynyl radicals. 1 is preferably understood to mean methoxy, trifluoromethoxy, 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, cyclooctyloxy, 2-ethylhexyloxy, pentafluoroethoxy and 2,2,2-trifluoroethoxy. Thioalkyl groups SR having 1 to 40 carbon atoms 1is understood to mean in particular methylthio, ethylthio, n-propylthio, i-propylthio, n-butylthio, i-butylthio, s-butylthio, t-butylthio, n-pentylthio, s-pentylthio, n-hexylthio, cyclohexylthio, n-heptylthio, cycloheptylthio, n-octylthio, cyclooctylthio, 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, an alkyl, alkoxy or thioalkyl group according to the present invention may be linear, branched or cyclic, in which one or more non-adjacent CH groups may be replaced by the groups mentioned above; in addition, one or more hydrogen atoms may be replaced by D, F, Cl, Br, I, CN or NO, preferably F, Cl or CN, more preferably F or CN.

[0012] having 5 to 40 aromatic ring atoms, in each case as defined above for R 2The aromatic or heteroaromatic ring systems, which may be substituted by radicals or hydrocarbyl radicals and which may be linked to the aromatic or heteroaromatic system via any desired position, are, inter alia, benzene, naphthalene, anthracene, benzanthracene, phenanthrene, pyrene, chrysene, perylene, fluoranthene, naphthacene, pentacene, benzopyrene, biphenyl, biphenylene, terphenyl, triphenylene, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, cis- or cycloalkyl-substituted aryl groups, or trans-indenofluorene, cis- or trans-indenocarbazole, cis- or trans-indolocarbazole, truxene, isotruxene, spirotruxene, spiroisotruxene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, Benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthoimidazole, phenanthroimidazole, pyridiimidazole, pyrazineimidazole, quinoxalineimidazole, oxazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, 1,2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, hexaazatriphenylene, benzopyridazine, pyrimidine, benzopyrimidine, Quinoxaline, 1,5-diazaanthracene, 2,7-diazapyrene, 2,3-diazapyrene, 1,6-diazapyrene, 1,8-diazapyrene, 4,5-diazapyrene, 4,5,9,10-tetraazapyrylene, pyrazine, phenazine, phenoxazine, phenothiazine, fluorubine, naphthyridine, azacarbazole, benzocarboline, phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,This is understood to mean radicals derived from 4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, tetrazole, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine, purine, pteridine, indolizine and benzothiadiazole, or combinations of these systems.

[0013] The expression that two or more radicals may together form a ring system is understood to mean the formation of an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system, and in the context of the present description should be understood to mean, inter alia, that two radicals are linked to each other by a chemical bond, with the formal elimination of two hydrogen atoms. This is illustrated by the following scheme:

[0014] [ka]

[0015] However, in addition, the above expression should also be understood to mean that if one of the two radicals is hydrogen, the second radical is bonded to the position to which the hydrogen atom is bonded to form a ring, which shall be illustrated by the following scheme:

[0016] [ka]

[0017] In a preferred embodiment of the present invention, the group incorporated in formula (1)

[0018] [ka]

[0019] is selected from the following groups (HetAr-1), (HetAr-2) and (HetAr-3):

[0020] [ka]

[0021] (In the formula, Ar 1 has the definition above and the dotted bond indicates the attachment of this group within the compound of formula (1).

[0022] In a preferred embodiment of the invention, all three Z groups are N, so the compound is preferably one of the following formulas (2):

[0023] [ka]

[0024] (wherein the symbols and subscripts used have the definitions given above).

[0025] In a further preferred embodiment of the present invention, Y 1 is O, so that the compound has one of the following formulas (3):

[0026] [ka]

[0027] (wherein the symbols and subscripts used have the definitions given above).

[0028] In a further preferred embodiment of the present invention, Y 2 is NAr 2 and therefore the compound has one of the following formulas (4):

[0029] [ka]

[0030] (wherein the symbols and subscripts used have the definitions given above).

[0031] Y 2 NAr 2 and if the carbazole group has at least two adjacent R radicals which together form a ring system, then preferably the carbazole group is selected from the groups of the following formulae (CARB-1) to (CARB-6):

[0032] [ka]

[0033] wherein the structures are each formed by one or more R radicals on the carbazole and one or more R radicals on the fused structure. 1 may be substituted by a radical, but is preferably unsubstituted; Y 3 is C(R 1 )2, NR 1 , O or S, preferably C(R 1 )2 or NR 1 , more preferably C(R 1 ) 2, where the structure is attached to a dibenzofuran or dibenzothiophene via a dotted bond).

[0034] In a further preferred embodiment of the present invention, all Z are N and simultaneously all Y 1 In a further preferred embodiment of the present invention, all Z are N and simultaneously all Y 2 is NAr 2 In a further preferred embodiment of the present invention, all Y 1 is O and at the same time all Y 2 is NAr 2 In a particularly preferred embodiment of the present invention, all Z are N and simultaneously all Y 1 is O and at the same time all Y 2 is NAr 2 and therefore the compound has one of the following formulas (5):

[0035] [ka]

[0036] (wherein the symbols and subscripts used have the definitions given above).

[0037] Y 1 The linkage of the group containing, i.e., dibenzofuran or dibenzothiophene, is preferably at the 8-position, i.e., Y 1 In addition, Y 2 The linkage of the group containing Y 2 =NAr 2 In the case of 2 In the case of =O or S, it is preferably via the 2-position, i.e. in both cases Y 2 Preferably via the para position to Y 2 In the case of =CR2, it is preferably via the 2-position.

[0038] The position numbering of dibenzofuran and carbazole is shown in the scheme below, with the position numbering of dibenzothiophene analogous to dibenzofuran and the position numbering of fluorene analogous to carbazole.

[0039] [ka]

[0040] Therefore, preferred embodiments of the compounds of formulae (1) to (5) are the compounds of formulae (1a) to (5a) below.

[0041] [ka]

[0042] [ka]

[0043] (wherein the symbols and subscripts used have the definitions given above).

[0044] In further preferred embodiments of the compounds of formulae (1), (2), (3), (4), (5), (1a), (2a), (3a), (4a) and (5a), p, q and r are the same or different in each occurrence and are 0 or 1, more preferably 0. In further preferred embodiments of the compounds of formulae (1), (2), (3), (4), (5), (1a), (2a), (3a), (4a) and (5a), S is the same or different in each occurrence and is 0, 1 or 2, more preferably 0 or 1, most preferably 0.

[0045] Therefore, the compound of the following formula (6) is particularly preferred:

[0046] [ka]

[0047] in which the symbols used have the above definitions and s is the same or different in each case and is 0 or 1.

[0048] A particularly preferred embodiment is a compound of formula (6a):

[0049] [ka]

[0050] in which the symbols used have the above definitions and s, which is the same or different in each case, is 0 or 1, preferably 0.

[0051] In a further preferred embodiment of the present invention, Ar 1, i.e. the substituents on the triazine or pyrimidine are in each case the same or different and are aromatic or heteroaromatic ring systems having 6 to 30 aromatic ring atoms, optionally substituted by one or more R radicals. More preferably, Ar 1 are in each case the same or different and are aromatic or heteroaromatic ring systems, in particular aromatic ring systems having 6 to 24 aromatic ring atoms, in particular 6 to 13 aromatic ring atoms, optionally substituted by one or more preferably non-aromatic R radicals. 1 When is a heteroaryl group, especially a triazine, pyrimidine, quinazoline or carbazole, an aromatic or heteroaromatic substituent R on the heteroaryl group may also be preferred.

[0052] Suitable aromatic or heteroaromatic ring systems Ar 1 are in each case the same or different and are selected from phenyl, biphenyl, in particular ortho-, meta- or para-biphenyl, terphenyl, in particular ortho-, meta- or para-terphenyl or branched terphenyl, quaterphenyl, in particular ortho-, meta- or para-quaterphenyl or branched quaterphenyl, fluorene which may be bonded via the 1, 2, 3 or 4 position, spirobifluorene which may be bonded via the 1, 2, 3 or 4 position, naphthalene which may be bonded via the 1 or 2 position, indole, benzofuran, benzothiophene, carbazole which may be bonded via the 1, 2, 3 or 4 position, dibenzofuran which may be bonded via the 1, 2, 3 or 4 position, dibenzothiophene which may be bonded via the 1, 2, 3 or 4 position, indenocarbazole, indolocarbazole, phenanthrene, triphenylene or a combination of two or three of these groups, each of which may be substituted by one or more R radicals, preferably non-aromatic R radicals. Ar 1When is a heteroaryl group, especially a triazine, pyrimidine, quinazoline or carbazole, aromatic or heteroaromatic R radicals on the heteroaryl group may also be preferred.

[0053] Here, Ar 1 are in each case preferably the same or different and are selected from the groups of the formulae Ar-1 to Ar-81

[0054] [ka]

[0055] [ka]

[0056] [ka]

[0057] [ka]

[0058] [ka]

[0059] where R is as defined above, the dotted bond represents a bond to the heteroaryl group, and additionally: A 1 is the same or different in each occurrence and is CR2, NR, O, or S; Ar 3 is the same or different, in each occurrence, a divalent aromatic or heteroaromatic ring system having 6 to 18 aromatic ring atoms, in each occurrence optionally substituted by one or more R radicals; n is 0 or 1, where n=0 is A 1means that no group is attached at this position, but instead the R radical is attached to the corresponding carbon atom; m is 0 or 1, where m=0 is Ar 3 This means that the aryl group is absent and the corresponding aromatic or heteroaromatic group is directly bonded to the triazine or pyrimidine group in formula (1).

[0060] Particularly preferably, Ar 1 The group is 1-dibenzofuranyl, i.e., A 1 =O and m=0, phenyl-1-dibenzofuranyl, i.e., A 1 =O, m=1, and Ar 3 = selected from the group consisting of radicals of formula Ar-16: para-phenylene, phenyl, ortho-biphenyl, meta-biphenyl, para-biphenyl, quaterphenyl, para-tert-butylphenyl, naphthyl, fluorenyl, especially 9,9-dimethyl-2-fluorenyl, and 1-dibenzothienyl.

[0061] In a further preferred embodiment of the present invention, Ar 2 , i.e., Y 2 =NAr 2 The substituents on the carbazole in each case are the same or different and are aromatic or heteroaromatic ring systems having 6 to 30 aromatic ring atoms, optionally substituted by one or more R radicals. More preferably, Ar 2 are in each case the same or different and are aromatic or heteroaromatic ring systems, especially aromatic ring systems having 6 to 24 aromatic ring atoms, especially 6 to 13 aromatic ring atoms, optionally substituted by one or more preferably non-aromatic R radicals. 2 When is a heteroaryl group, especially a triazine, pyrimidine, quinazoline or carbazole, an aromatic or heteroaromatic substituent R on the heteroaryl group may also be preferred.

[0062] Suitable aromatic or heteroaromatic ring systems Ar 2are in each case the same or different and are selected from phenyl, biphenyl, in particular ortho-, meta- or para-biphenyl, terphenyl, in particular ortho-, meta- or para-terphenyl or branched terphenyl, quaterphenyl, in particular ortho-, meta- or para-quaterphenyl or branched quaterphenyl, fluorene which may be bonded via the 1, 2, 3 or 4 position, spirobifluorene which may be bonded via the 1, 2, 3 or 4 position, naphthalene which may be bonded via the 1 or 2 position, indole, benzofuran, benzothiophene, carbazole which may be bonded via the 1, 2, 3 or 4 position, dibenzofuran which may be bonded via the 1, 2, 3 or 4 position, dibenzothiophene which may be bonded via the 1, 2, 3 or 4 position, indenocarbazole, indolocarbazole, phenanthrene, triphenylene or a combination of two or three of these groups, each of which may be substituted by one or more R radicals, preferably non-aromatic R radicals. 2 When is a heteroaryl group, especially a triazine, pyrimidine, quinazoline or carbazole, aromatic or heteroaromatic R radicals on the heteroaryl group may also be preferred.

[0063] Here, Ar 2 are in each case preferably the same or different and are selected from the above detailed groups of formulae Ar-1 to Ar-81.

[0064] Particularly preferably, Ar 2 The group is 1-dibenzofuranyl, i.e., A 1 =O and m=0, phenyl-1-dibenzofuranyl, i.e., A 1 =O, m=1 and Ar 3 = selected from the group consisting of radicals of formula Ar-16: para-phenylene, phenyl, ortho-biphenyl, meta-biphenyl, para-biphenyl, ortho-para-terphenyl, quaterphenyl, para-tert-butylphenyl, triphenylene and N-phenyl-3-carbazolyl.

[0065] In a preferred embodiment of the invention, R is the same or different in each occurrence and is H, D, F, N(Ar′) 2 , CN, OR 1 , a linear alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, or a branched or cyclic alkyl group having 3 to 10 carbon atoms, wherein the alkyl or alkenyl group each comprises one or more R 1 radicals, but preferably unsubstituted, wherein one or more non-adjacent CH groups are optionally replaced by O, or an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, in each case selected from the group consisting of 1 at the same time, two R radicals may also together form an aliphatic, aromatic or heteroaromatic ring system. More preferably, R is in each case the same or different and is H, N(Ar')2, a linear alkyl group having 1 to 6 carbon atoms, in particular having 1, 2, 3 or 4 carbon atoms, or a branched or cyclic alkyl group having 3 to 6 carbon atoms, where the alkyl group is in each case one or more of R 1 radicals, but preferably unsubstituted), or an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, in each case selected from the group consisting of one or more R 1 A radical, preferably non-aromatic R 1 Most preferably, R, in each occurrence, is the same or different and is selected from the group consisting of H or an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, preferably 6 to 18 aromatic ring atoms, more preferably 6 to 13 aromatic ring atoms, and in each occurrence, one or more R 1 A radical, preferably non-aromatic R 1 It may be substituted by a radical.

[0066] In a further preferred embodiment of the invention, Ar' is an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms and is selected from the group consisting of one or more R 1 In a particularly preferred embodiment of the invention, Ar' is an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, even more preferably 6 to 18 aromatic ring atoms, especially 6 to 13 aromatic ring atoms, and may be substituted by one or more preferably non-aromatic R radicals. 1 It may be substituted by a radical.

[0067] Suitable aromatic or heteroaromatic ring systems R or Ar' are phenyl, biphenyl, especially ortho-, meta- or para-biphenyl, terphenyl, especially ortho-, meta- or para-terphenyl or branched terphenyl, quaterphenyl, especially ortho-, meta- or para-quaterphenyl or branched quaterphenyl, fluorene, which may be bonded via the 1, 2, 3 or 4 position, spirobifluorene, which may be bonded via the 1, 2, 3 or 4 position, naphthalene, which may be bonded via the 1 or 2 position, indole, and n is an integer from 1 to 4, and n is an integer from 1 to 4, and n is an integer from 1 to 4, and n is an integer from 1 to 4, and n is an integer from 1 to 4, and n is an integer from 1 to 4, and n is an integer from 1 to 4, and n is an integer from 1 to 4, and n is an integer from 1 to 4, and n is an integer from 1 to 4, and n is an integer from 1 to 4, and n is an integer from 1 to 4, and n is an integer from 1 to 4, and n is an integer from 1 to 4, and n is an integer from 1 to 4, and n is an integer from 1 to 4 1 When R or Ar' is a heteroaryl group, especially a triazine, pyrimidine or quinazoline, the aromatic or heteroaromatic R on the heteroaryl group may be substituted. 1 Radicals may also be preferred.

[0068] The R group here (in the case of an aromatic or heteroaromatic ring system), or Ar′, is preferably selected from the groups of the formulae R-1 to R-81 below:

[0069] [ka]

[0070] [ka]

[0071] [ka]

[0072] [ka]

[0073] [ka]

[0074] (In the formula, R 1 has the above definition, and the dotted bond represents a bond to the base skeleton in formula (1) or Ar 1 Or Ar 2 or to a nitrogen atom in an N(Ar')2 group, in addition: A 1 are the same or different in each case, and C(R 1 )2, NR 1 , O or S; Ar 3 are the same or different, in each occurrence, a divalent aromatic or heteroaromatic ring system having 6 to 18 aromatic ring atoms, and in each occurrence one or more R 1 may be substituted with a radical; n is 0 or 1, where n=0 is A 1 If no group is attached at this position, R 1means that the radical is attached to the corresponding carbon atom; m is 0 or 1, where m=0 is Ar 3 It means that the group is absent and the corresponding aromatic or heteroaromatic group is directly attached to the base skeleton of formula (1) or to the nitrogen atom in the N(Ar')2 group in the preferred embodiments; provided that when these groups are in the Ar' embodiment, for structures (R-12), (R-17), (R-21), (R-25), (R-26), (R-30), (R-34), (R-38) and (R-39), m=1.

[0075] Ar 1 or Ar 2 Regarding Ar-1 to Ar-81 groups or R or Ar', R-1 to R-81 groups are two or more 1 If the aryl group is present, these possible options include A 1 In this case, a preferred embodiment is one of A 1 The group is NR or NR 1 And the other A 1 The group is C(R)2 or C(R 1 )2 or both A 1 The group is NR or NR 1 or both A 1 In a particularly preferred embodiment of the present invention, two or more A groups are 1 Ar having a group 1 , Ar 2 In the R or Ar′ group, at least one A 1 The group is C(R)2 or C(R 1 )2 or NR or NR 1 It is.

[0076] A 1 NR or NR 1 When the nitrogen atom is 1 is preferably an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, and one or more R 1 or R 2In a particularly preferred embodiment, R or R 1 The substituents are in each case the same or different and are aromatic or heteroaromatic ring systems having 6 to 24 aromatic ring atoms, preferably 6 to 12 aromatic ring atoms, and do not have any fused aryl or heteroaryl groups in which two or more aromatic or heteroaromatic 6-membered ring groups are directly fused to each other, and in each case also have one or more R 1 or R 2 Particularly preferred are phenyl, biphenyl, terphenyl and quaterphenyl having bonding patterns as listed above for Ar-1 to Ar-11 or R-1 to R-11, where these structures may be substituted by one or more R 1 or R 2 It may be substituted with a radical, but is preferably unsubstituted.

[0077] A 1 is C(R)2 or C(R 1 )2, the substituent R or R bonded to this carbon atom 1 are preferably in each case the same or different and are a linear alkyl group having 1 to 10 carbon atoms or a branched or cyclic alkyl group having 3 to 10 carbon atoms or an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, and one or more R 1 or R 2 It may be substituted by a radical. Most preferably, it is R or R 1 is a methyl group or a phenyl group. In this case, R or R 1 The radicals may also form a ring system together, resulting in a spiro system.

[0078] In a further preferred embodiment of the present invention, R 1 are the same or different in each case, H, D, F, CN, OR 2, a linear alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms or a branched or cyclic alkyl group having 3 to 10 carbon atoms, where the alkyl or alkenyl group is in each case one or more R 2 radicals), in which one or more non-adjacent CH groups are optionally replaced by O, or an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, in each case selected from the group consisting of one or more R 2 At the same time, two or more R 1 The radicals may also together form an aliphatic ring system. In a particularly preferred embodiment of the invention, R 1 are in each case the same or different and are H, a linear alkyl group having 1 to 6 carbon atoms, in particular 1, 2, 3 or 4 carbon atoms, or a branched or cyclic alkyl group having 3 to 6 carbon atoms, where the alkyl group is selected from one or more R 2 radicals, but preferably unsubstituted), or an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, preferably 6 to 18 aromatic ring atoms, more preferably 6 to 13 aromatic ring atoms, in each case selected from the group consisting of one or more R 2 It may be substituted with a radical, but is preferably unsubstituted.

[0079] In a further preferred embodiment of the present invention, R 2 is in each occurrence the same or different and is H, F, an alkyl group having 1 to 4 carbon atoms, or an aryl group having 6 to 10 carbon atoms, which may be substituted by an alkyl group having 1 to 4 carbon atoms, but is preferably unsubstituted.

[0080] The above preferences may occur individually or together. The above preferences are preferred when occurring together.

[0081] Examples of suitable compounds of the present invention are the structures illustrated below:

[0082] [ka]

[0083] [ka]

[0084] [ka]

[0085] [ka]

[0086] [ka]

[0087] [ka]

[0088] The compounds of the invention can be prepared by synthetic procedures known to those skilled in the art, such as bromination, Suzuki coupling, Ullmann coupling, Hartwig-Buchwald coupling, etc. Suitable synthetic methods are illustrated in general terms in the following schemes, where the symbols and indices used have the above definitions. The compounds of the invention are 1Starting from -functionalized dichloropyrimidines or -triazines, they may now be prepared by reaction with 1-dibenzofuranboronic acid or its ester in a Suzuki coupling. The reaction may be carried out in two steps as shown in scheme 1, or in one step if a similarly substituted 1-dibenzofuranboronic acid or -boronic acid ester is used. The Suzuki coupling may be carried out in an aprotic solvent (e.g., toluene, dioxane, DHF, DMF, DMSO) or with the addition of a protic solvent (e.g., alcohol, water). The catalysts used are typically Pd catalysts or Pd compounds (palladium acetate, Pd-dba, etc.) and phosphines (triphenylphosphine, tri-o-tolylphosphine, S-Phos, X-Phos, BINAP, DPPF, Xanth-Phos, etc.). Bases used in the coupling reaction include organic salts (sodium, potassium or cesium carbonate, sodium, potassium or cesium phosphate, sodium, potassium or cesium fluoride, sodium, potassium or cesium borate) and their hydrates.

[0089] [ka]

[0090] The compounds of the present invention can also be processed by deposition under reduced pressure, but the main object of the present invention is to provide compounds for processing from liquid phase, for example by spin-coating or printing methods.For this purpose, formulations of the compounds of the present invention are required.These formulations can be, for example, solutions, dispersions or emulsions, preferably solutions.For this purpose, it may be preferable to use a mixture of two or more solvents. Suitable preferred solvents are, for example, toluene, anisole, o-, m- or p-xylene, methyl benzoate, mesitylene, tetralin, veratrole, THF, methyl-THF, THP, chlorobenzene, dioxane, phenoxytoluene, especially 3-phenoxytoluene, (-)-fenchone, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, 1-methylnaphthalene, 2-methylbenzothiazole, 2-phenoxyethanol, 2-pyrrolidinone, 3-methylanisole, 4-methylanisole, 3,4-dimethylanisole, 3,5-dimethylanisole, acetophenone, α-terpineol, benzothiazole, butyl benzoate, Cumene, cyclohexanol, cyclohexanone, cyclohexylbenzene, decalin, dodecylbenzene, ethyl benzoate, indane, NMP, p-cymene, phenetole, 1,4-diisopropylbenzene, dibenzyl ether, diethylene glycol butyl methyl ether, triethylene glycol butyl methyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, tripropylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 2-isopropylnaphthalene, pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene, 1,1-bis(3,4-dimethylphenyl)ethane, 2-methylbiphenyl, 3-methylbiphenyl, 1-methylnaphthalene, 1-ethylnaphthalene, ethyl octanoate, diethyl sebacate, octyl octanoate, heptylbenzene, methyl isovalerate, cyclohexyl hexanoate, alkoxy-substituted ethyl benzoates, especially 2-methoxyethyl benzoate and 4-methoxyethyl benzoate, alkyl-substituted ethyl benzoates, especially 2-methylethyl benzoate and 4-methylethyl benzoate, propylene carbonate, ethylene carbonate, isopropylbiphenyl, especially 2-isopropylbiphenyl, 3-isopropylbiphenyl and 2,2'-diisopropylbiphenyl, amyl benzoate, isoamyl benzoate, 1-isopropylnaphthalene, 2-isopropylnaphthalene, 1-isopropylnaphthalene, diisopropylnaphthalene, benzyl benzoate or mixtures of these solvents.

[0091] Thus, the present invention further provides a formulation comprising at least one compound of the present invention and at least one further compound.The further compound may be, for example, a solvent, in particular one of the above-mentioned solvents or a mixture of these solvents.The further compound may alternatively be at least one further organic or inorganic compound, such as a light-emitting compound and / or a further matrix material, which are also used in electronic devices.Suitable light-emitting compounds and further matrix materials are listed below in connection with organic electroluminescent devices.The further compound may also be a polymer.

[0092] The compounds of the present invention are suitable for use in electronic devices, especially organic electroluminescent devices.Thus, the present invention further provides the use of the compounds of the present invention in electronic devices, especially organic electroluminescent devices.

[0093] The present invention still further provides an electronic device comprising at least one compound of the present invention.

[0094] The electronic device according to the invention is a device comprising at least one layer containing at least one organic compound. This component may also comprise layers made of inorganic materials or entirely inorganic materials. The electronic device is preferably selected from the group consisting of organic electroluminescent devices (OLEDs), 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), dye-sensitized organic solar cells (DSSCs), organic photodetectors, organic photoreceptors, organic field quenching devices (O-FQDs), light emitting electrochemical cells (LECs), organic laser diodes (O-lasers) and organic plasmonic light emitting devices, but is preferably selected from organic electroluminescent devices (OLEDs), more preferably from phosphorescent OLEDs.

[0095] The organic electroluminescent device comprises a cathode, an anode and at least one light-emitting layer. Besides these layers, it may also comprise further layers, for example in each case 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 generating layers. It is also possible to introduce an intermediate layer with exciton blocking function, for example between two light-emitting layers. However, it should be pointed out that not all of these layers necessarily have to be present. In this case, it is possible that the organic electroluminescent device contains a light-emitting layer or that it contains several light-emitting layers. If several light-emitting layers are present, these preferably have several emission maxima in the range 380 nm to 750 nm as a whole, so that the overall result is a white emission; in other words, various light-emitting compounds that can fluoresce or phosphoresce are used in the light-emitting layers. Particularly preferred are systems with three light-emitting layers, where the three layers show blue, green and orange or red emission. The organic electroluminescent device of the present invention may also be a tandem OLED, especially in the case of a white-emitting OLED.

[0096] The compounds of the present invention according to the above detailed embodiments may be used in different layers.Preferred is an organic electroluminescent device that comprises the compound of formula (1) or the preferred embodiments listed above in the light-emitting layer as the matrix material of phosphorescent emitter or emitter that shows TADF (thermally activated delayed fluorescence), especially phosphorescent emitter.In this case, the organic electroluminescent device may comprise a light-emitting layer or may comprise multiple light-emitting layers, where at least one light-emitting layer comprises at least one compound of the present invention as the matrix material.In addition, the compounds of the present invention may also be used in the electron transport layer and / or hole blocking layer.

[0097] When the compounds of the present invention are used as matrix materials of phosphorescent compounds in the light-emitting layer, they are preferably used in combination with one or more phosphorescent materials (triplet emitters).Phosphorescence in the context of the present invention is understood to mean luminescence from excited states with higher spin multiplicity, i.e. spin states>1, especially excited triplet states.In the context of this application, all luminescent complexes containing transition metals or lanthanides, especially all iridium, platinum and copper complexes, will be considered as phosphorescent compounds.

[0098] Examples of the above mentioned luminophores are disclosed in 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, WO 2018 / 011186 and WO 2018 / 041769, WO 2019 / 020538, WO 2018 / 178001, WO 2019 / 115423 or WO 2019 / 158453. In general, all phosphorescent complexes that are used in phosphorescent OLEDs according to the prior art and that are known to a person skilled in the art in the field of organic electroluminescence are suitable, and a person skilled in the art will be able to use further phosphorescent complexes without using the technology of the present invention.

[0099] Examples of phosphorescent dopants are given below.

[0100] [ka]

[0101] [ka]

[0102] [ka]

[0103]

change

[0104]

change

[0105]

change

[0106]

change

[0107]

change

[0108]

change

[0109]

change

[0110]

change

[0111]

change

[0112] If the organic electroluminescent device is produced from solution, the mixture of the total host comprising the compound of the invention and the light-emitting compound comprises 99% to 1% by weight, preferably 97% to 50% by weight, more preferably 96% to 60% by weight, especially preferably 95% to 75% by weight of the host comprising the compound of the invention, and correspondingly the mixture comprises 1% to 99% by weight, preferably 3% to 50% by weight, more preferably 5% to 40% by weight, especially preferably 5% to 25% by weight of the emitter, based on the total mixture of emitter and all matrix materials.

[0113] As will be shown in more detail below, the host material may also be a mixture of two or more materials, at least one of which is a compound of the present invention. The proportion of the host material of the present invention, i.e. the compound of formula (1) or preferred embodiment here, based on all the components of the light-emitting layer, is 99% to 1% by weight, preferably 95% to 10% by weight, more preferably 80% to 20% by weight, most preferably 70% to 25% by weight.

[0114] When the organic electroluminescent device is produced by vapor deposition, the mixture of the compound of the invention and the light-emitting compound contains 99% to 1% by volume, preferably 98% to 10% by volume, more preferably 97% to 60% by volume, especially 95% to 80% by volume of the compound of the invention, based on the entire mixture of the light emitter and the matrix material, whereas the mixture contains 1% to 99% by volume, preferably 2% to 90% by volume, more preferably 3% to 40% by volume, especially 5% to 20% by volume of the light emitter, based on the entire mixture of the light emitter and the matrix material.

[0115] A further preferred embodiment of the present invention is the use of the compounds of the present invention as a matrix material for phosphorescent emitters in combination with a further matrix material.Suitable matrix materials that can be used in combination with the compounds of the present invention include aromatic ketones, aromatic phosphine oxides or aromatic sulfoxides or sulfones, triarylamines, carbazole derivatives, such as CBP (N,N-biscarbazolylbiphenyl), according to WO 2004 / 013080, WO 2004 / 093207, WO 2006 / 005627 or WO 2010 / 006680, or the like, as described in WO 2005 / 039246, US Carbazole derivatives as disclosed in JP 2005 / 0069729, JP 2004 / 288381, EP 1205527, WO 2008 / 086851 or WO 2013 / 041176, for example indolocarbazole derivatives according to WO 2007 / 063754 or WO 2008 / 056746, indenocarbazole derivatives according to WO 2010 / 136109, WO 2011 / 000455, WO 2013 / 041176 or WO 2013 / 056776, azacarbazole derivatives according to EP 1617710, EP 1617711, EP 1731584, JP 2005 / 347160, for example bipolar matrix materials according to WO 2007 / 137725, silanes, for example, according to WO 2005 / 111172, azaboroles or boronic esters, for example, according to WO 2006 / 117052, triazine derivatives, for example, according to WO 2007 / 063754, WO 2008 / 056746, WO 2010 / 015306, WO 2011 / 057706, WO 2011 / 060859 or WO 2011 / 060877, zinc complexes, for example, according to EP 652273 or WO 2009 / 062578, diazasilol or tetraazasilol derivatives, for example, according to WO 2010 / 054729, diazaphosphole derivatives, for example, according to WO 2011 / 042107, WO 2011 / 060867, WO 2011 / 088877 and WO 2012 / 143080, triphenylene derivatives, for example, according to WO 2012 / 048781, dibenzofuran derivatives, for example, according to WO 2015 / 169412, WO 2016 / 015810, WO 2016 / 023608, WO 2017 / 148564 or WO 2017 / 148565, or dibenzothiophene derivatives.

[0116] Similarly, additional phosphorescent emitters that emit at shorter wavelengths than the actual emitter can be present as cohosts in the mixture, for example, if a red-emitting OLED is to be constructed, a green phosphorescent emitter can be used in addition to a red phosphorescent emitter.

[0117] In addition, if there are compounds that do not play a significant role in charge transport, they can also be used as additional "wide band gap" matrix materials, for example as described in WO 2010 / 108579, WO 2016 / 184540 or unpublished application EP 19152285.3. In a preferred embodiment of the present invention, the wide band gap material is a hydrocarbon, i.e. does not contain heteroatoms.

[0118] A wide band gap matrix material in the context of the present invention is a material which, in the emissive layer mixture used, is characterized by a HOMO which is at least 0.2 eV lower than the highest HOMO of all other materials present in the mixture (emitter and host materials) and a LUMO which is at least 0.2 eV higher than the lowest LUMO of all other materials present in the mixture (emitter and host materials).

[0119] The reported energy values ​​relate to the isolated compounds and are confirmed as shown below.

[0120] The HOMO (Highest Occupied Molecular Orbital) and LUMO (Lowest Unoccupied Molecular Orbital) energies as well as triplet levels of the materials are determined by quantum chemical calculations. For this, in this case the "Gaussian09, Revision D.01" software package (Gaussian Inc.) is used. Alternatively, it is possible to use other software packages if the same methods are implemented therein. To calculate the metal-free organic substances, a geometry optimization is first performed with charge 0 and multiplicity 1 by the semi-empirical method AM1 (Gaussian input line "#AM1 opt"). Subsequently, based on the optimized geometry, a (single-point) energy calculation is performed for the electronic ground state and triplet levels. This is performed using the TDDFT (Time-Dependent Density Functional Theory) method B3PW91 with the 6-31G(d) basis set (Gaussian input line "# B3PW91 / 6-31G(d) td=(50-50, nstates=4)") (charge 0, multiplicity 1). For organometallic compounds, the geometries are optimized by the Hartree-Fock method and the LanL2MB basis set (Gaussian input line "#HF / LanL2MB opt") (charge 0, multiplicity 1). Energy calculations are performed similarly to the organic substances as described above, except that the "LanL2DZ" basis set is used for the metal atoms and the "6-31G(d)" basis set is used for the ligands (Gaussian input line "#B3PW91 / gen pseudo=lanl2 td=(50-50, nstates=4)"). From the energy calculations, the HOMO (alpha occ.eigenvalues) is obtained as the last orbital occupied by two electrons and the LUMO (alpha virt.eigenvalues) as the first unoccupied orbital, in Hartree units (HEh and LEh). This is used to determine the HOMO and LUMO values ​​in electron volts, calibrated by cyclic voltammetry measurements as follows: LUMO(eV)=(1.0658*LEh*27.212)-0.5049 HOMO(eV)=(0.8308*HEh*27.212)-1.1180 These values ​​should be considered as the HOMO and LUMO of the material in the context of this application.

[0121] Examples of suitable wide band gap materials are the structures shown in the table below.

[0122] [ka]

[0123] [ka]

[0124] [ka]

[0125] In addition, the compounds of the present invention can be used in hole blocking and / or electron transporting layers.

[0126] In the further layer of the organic electroluminescent device of the present invention, it is possible to use any material that is usually used according to the prior art.Therefore, those skilled in the art can use any material that is known in organic electroluminescent device in combination with the compound of the present invention or preferred embodiment of formula (1) without using the technology of the present invention.

[0127] Further preferred is an organic electroluminescent device, characterized in that one or more layers are applied by a sublimation process. In this case, the material is deposited at 10 -5 Less than mbar, preferably less than 10 -6 The deposition is performed at an initial pressure of less than 10 mbar. However, the initial pressure can be lower or higher, e.g. -7 It is also possible to be below mbar.

[0128] Likewise preferred are organic electroluminescent devices, characterized in that one or more layers are applied by the OVPD (organic vapor phase deposition) method or with the aid of carrier gas sublimation. In this case, the materials are preferably 10 -5 It is applied at pressures between mbar and 1 bar. A special case of this method is the OVJP (Organic Vapor Jet Printing) method, in which the material is applied directly by a nozzle and thus structured (for example, MS Arnold et al., Appl. Phys. Lett. 2008, 92, 053301).

[0129] Further preferred is an organic electroluminescent device characterized in that one or more layers are produced from solution, for example by spin coating, or by any printing method, for example inkjet printing, LITI (light-induced thermal imaging, thermal transfer printing), screen printing, flexographic printing, offset printing or nozzle printing.Compounds of the present invention have been found to be particularly suitable for processing from solution.

[0130] In addition, hybrid processes are possible, for example where one or more layers are applied from solution and one or more further layers are applied by vapor deposition, for example it is possible to apply an emissive layer from solution and an electron transport layer by vapor deposition.

[0131] These methods are generally known to those skilled in the art and can be applied by those skilled in the art to organic electroluminescent devices containing the compounds of the present invention without using the techniques of the present invention.

[0132] The compounds of the present invention are very suitable for processing from solution. At the same time, they have very good solubility in standard organic solvents and high glass transition temperatures. The use of the compounds of the present invention as matrix materials for phosphorescent emitters in organic electroluminescent devices produced from solution brings about a significant improvement in the lifetime of the organic electroluminescent device compared to the compounds of the prior art, especially compared to compounds that contain only one dibenzofuran-carbazole unit on the triazine, or compounds in which the triazine is substituted by two or more 1-dibenzofuran groups but only one dibenzofuran group is substituted by one carbazole group. At the same time, the further properties of the organic electroluminescent device, especially the efficiency and voltage, are comparable or superior.

[0133] The present invention is illustrated in detail by the following examples, which are not intended to be limiting in any way.

[0134] [example] The following syntheses are carried out under a protective gas atmosphere in dry solvents unless otherwise specified. Solvents and reagents can be purchased, for example, from Sigma-ALDRICH or ABCR. The respective numbers in square brackets or quoted for individual compounds relate to the CAS numbers of compounds known from the literature. Stage 1: BB-1a

[0135] [ka]

[0136] 100 g (26 mmol) of 1-bromo-8-iododibenzofuran (CAS: 1822311-11-4), 92.4 g (32 mmol) of (9-phenyl-9H-carbazol-3-yl)boronic acid, 85.2 g (61 mmol) of potassium carbonate and 15.5 g (13 mmol) of tetrakis(triphenylphosphine)palladium(0) are mixed in 1 l of ethylene glycol dimethyl ether / water (3:1) and heated under reflux overnight. The mixture is allowed to return to room temperature and the precipitate is filtered off and washed with water and ethanol. Yield: 86 g (176 mmol; 66%).

[0137] The following compounds can be prepared similarly:

[0138] [ka]

[0139] [ka]

[0140] Stage 2: BB-2a

[0141] [ka]

[0142] 86 g (176 mmol) of 3-(9-bromodibenzofuran-2-yl)-9-phenyl-9H-carbazole, 82.1 g (320 mmol) of 4,4,5,5,4',4',5',5'-octamethyl-[2,2']bi[[1,3,2]dioxaborolanyl], 52.4 g (530 mmol) of potassium acetate and 2.8 g (12 mmol) of palladium acetate are mixed in 1 l of DMF and stirred at 100° C. After 24 h, the reaction mixture is allowed to cool to room temperature and the mixture is concentrated to one third under reduced pressure. Water is added, the precipitated solid is filtered off, washed with water, ethanol and heptane and further purified by filtering through silica using THF as eluent. The product is obtained by removing the solvent under reduced pressure. Yield: 58.2 g (109 mmol; 62%).

[0143] The following compounds can be prepared similarly:

[0144] [ka]

[0145] [ka]

[0146] [ka]

[0147] Stage 3: BB-3a

[0148] [ka]

[0149] 21.1 g (85.4 mmol) of 1-bromodibenzofuran in 100 ml of THF are added dropwise to 2.27 g (93.5 mmol) of magnesium (with the addition of iodine to initiate the Grignard reaction) and the mixture is heated to reflux for 2 hours. 350 ml of THF are added and the reaction mixture is allowed to warm to room temperature. The Grignard reagent is added dropwise to 15 g (81 mmol) of 2,4,6-trichloro[1,3,5]triazine dissolved in 150 ml of THF at -10°C. The mixture is allowed to stir overnight at room temperature. The mixture is then cooled to 0°C and 8 ml of hydrochloric acid (1M) are added dropwise. The mixture is stirred for 1 hour and then 400 ml of water are added. The organic phase is removed and washed with water. The aqueous phase is extracted with ethyl acetate. The organic phases are combined and concentrated under reduced pressure. The crude product is purified by flash chromatography (heptane / dichloromethane 10:1). Yield: 24.0 g (75.9 mmol; 89%). Stage 4 (symmetric): Compound 1

[0150] [ka]

[0151] 24 g (75.9 mmol) of 2,4-dichloro-6-dibenzofuran-1-yl-[1,3,5]triazine, 80.3 g (150 mmol) of 9-phenyl-3-[9-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-dibenzofuran-2-yl]-9H-carbazole, 2.2 g (1.9 mmol) of tetrakis(triphenylphosphine)palladium(0) and 15.7 g (113.9 mmol) of potassium carbonate are mixed in 500 ml of water / THF (1:3) and stirred at 70° C. overnight. The reaction mixture is subsequently brought to room temperature, ethyl acetate is added and the phases are separated. The organic phase is washed with water and the aqueous phase is extracted with ethyl acetate. The combined organic phases are concentrated under reduced pressure and purified by flash chromatography (heptane / THF 10:1). The product is purified by recrystallization from heptane / toluene. -4 Further purification by vacuum extraction at 375 nm (mbar). Yield: 22.6 g (21.28 mmol; 28%).

[0152] The following compounds can be prepared similarly:

[0153] [ka]

[0154] [ka]

[0155] [ka]

[0156] [ka]

[0157] Stage 5 (asymmetric): BB-4a

[0158] [ka]

[0159] 24 g (75.9 mmol) of 2,4-dichloro-6-dibenzofuran-1-yl-[1,3,5]triazine, 36.6 g (68.3 mmol) of 9-phenyl-3-[9-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-dibenzofuran-2-yl]-9H-carbazole, 2.2 g (1.9 mmol) of tetrakis(triphenylphosphine)palladium(0) and 15.7 g (113.9 mmol) of potassium carbonate are mixed in 500 ml of water / THF (1:3) and stirred at 70° C. overnight. The mixture is allowed to warm to room temperature, ethyl acetate is added and the phases are split. The organic phase is washed with water and the aqueous phase is extracted with ethyl acetate. The combined organic phases are concentrated under reduced pressure and purified by flash chromatography (heptane / THF 10:1). Yield: 30 g (43.5 mmol; 58%).

[0160] The following compounds can be prepared similarly:

[0161] [ka]

[0162] Stage 6 (asymmetric): Compound 1.1

[0163] [ka]

[0164] 29 g (42.1 mmol) of 3-[9-(4-chloro-6-dibenzofuran-1-yl-[1,3,5]triazin-2-yl)-dibenzofuran-2-yl]-9-phenyl-9H-carbazole, 33.6 g (44 mmol) of BB-2b, 1.2 g (1.1 mmol) of tetrakis(triphenylphosphine)palladium(0) and 8.7 g (63.1 mmol) of potassium carbonate are mixed in 500 ml of water / THF (1:3) and stirred at 70° C. overnight. The reaction mixture is brought to room temperature, ethyl acetate is added and the phases are split. The organic phase is washed with water and the aqueous phase is extracted with ethyl acetate. The combined organic phases are concentrated under reduced pressure. The product is purified by flash chromatography (heptane / THF 10:1) and then by recrystallization (heptane / toluene). Yield: 20.6 g (16.0 mmol; 38%).

[0165] In a similar manner, the following compounds can be synthesized:

[0166] [ka]

[0167] [ka]

[0168] Example of a solution-processed device: OLED fabrication There are many descriptions of the production of vapor-deposited OLEDs in the literature, for example in WO 2004 / 058911. The production of solution-based OLEDs is detailed, for example, in WO 2004 / 037887 and WO 2010 / 097155. The following example combines two production methods, so that the layers up to and including the emitting layer are processed from solution, and the subsequent layers (hole-blocking layer / electron-transporting layer) are applied by vapor deposition under reduced pressure. For this, the general methods mentioned above are adapted to the situation described here (layer thickness variations, materials) and combined as follows:

[0169] The OLED configuration used is as follows: - Substrate, - ITO (50 nm), - Buffer material (20nm), - Hole transport layer (HTL, 20 nm), - Emitting layer (EML, 50 nm), - Electron transport layer (ETL, 20nm), - Electron injection layer (EIL, 3nm), - Al cathode (100 nm).

[0170] The substrates used are glass plaques coated with a structured ITO (indium tin oxide) with a thickness of 50 nm. For better processing, these are coated with the buffer material PEDOT:PSS (poly(3,4-ethylenedioxy-2,5-thiophene):polystyrenesulfonate) from Heraeus Precious Metals GmbH & Co.KG. The spin coating is carried out from water under air. The layer is subsequently baked at 180 ° C for 10 min. The coated glass plaques are thus provided with a hole transport layer and an emission layer. The hole transport layer is a polymer with the structure shown in table 1, which can be synthesized according to WO 2010 / 097155. If, as is the case here, a layer thickness of 20 nm, typical of a device, is to be achieved by spin coating, the polymer is dissolved in toluene so that the solution typically has a solids content of about 5 g / l. The layer is spun in an inert gas atmosphere, in this case nitrogen, and baked at 220 ° C for 30 min.

[0171] The emissive layer always consists of at least one matrix material (host material) and a light-emitting dopant (emitter). Here, details given in the form H1(92%):D1(8%) mean that the material H1 is present in the emissive layer in a weight percentage of 92% and the dopant D1 in a weight percentage of 8%. The mixture of the emissive layer is dissolved in toluene. Here, if a layer of a thickness of 50 nm, typical for a device, is to be achieved by spin coating, the typical solid content of such a solution is about 14 g / l. The layer is spun in an inert gas atmosphere, in this case nitrogen, and baked for 10 minutes. The materials used are given in Table 1. The respective compositions of the emissive layer, the thickness of the EML layer and its baking temperature are given in Table 2.

[0172] The materials for the electron transport layer and the cathode are applied by thermal evaporation in a vacuum chamber. The electron transport layer may, for example, consist of more than one material, which are added to each other by co-evaporation in a certain volume percentage. Here, details given in the form ETM:EIM (50%:50%) mean that the ETM and EIM materials are present in the layer in a volume percentage of 50% each. In this case, the electron transport layer consists of the material ETM with a layer thickness of 20 nm. The electron injection layer is formed from 3 nm of the EIM material. Both materials are given in Table 1. The final layer is a cathode layer of aluminum with a layer thickness of 100 nm.

[0173] OLEDs are characterized in the standard way. For this, electroluminescence spectra are recorded, the current efficiency (measured in cd / A) and the external quantum efficiency (EQE, measured in percent) are calculated as a function of luminance from the current-voltage-luminance characteristic (IUL characteristic), assuming Lambertian emission characteristics, and finally the lifetime of the component is determined. The electroluminescence spectrum is measured at 1000 cd / m 2 The x and y color coordinates of CIE 1931 are calculated from the luminance of 1000 cd / m 2 The parameter EQE at is 1000cd / m 2 This refers to the external quantum efficiency at an operating brightness of 4000cd / m 2 Lifetime LT95 at a starting brightness of 4000cd / m 2 Decreased by 5% to 3800cd / m 2 The time elapsed until the LED reaches the threshold of 100% is shown in Table 3.

[0174] [Table 1-1]

[0175] [Table 1-2]

[0176] [Table 1-3]

[0177] [Table 2]

[0178] [Table 3]

[0179] The results in Table 3 show that it is possible to achieve not only a small improvement in external quantum efficiency, but also a clear improvement in lifetime. The structures found are therefore suitable as hosts for processing from solution, leading to excellent performance data.

Claims

1. Compound of formula (2) 【Chemistry 1】 (wherein the symbols and subscripts used are as follows: Y １ is the same or different in each occurrence and is O or S; Y ２ is O; Ar 1 is an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, optionally substituted by one or more R radicals; R is, in each occurrence, the same or different, H, D, F, a linear alkyl group having 1, 2, 3 or 4 carbon atoms, wherein said alkyl group is, in each occurrence, one or more of R １ radicals), or an aromatic or heteroaromatic ring system having 6 to 13 aromatic ring atoms, in each case one or more R １ may be substituted with a radical; R １ is the same or different in each occurrence and is H or D; p, q, r, in each occurrence, are the same or different and are 0, 1, 2 or 3; s is the same or different in each occurrence and is 0, 1, 2, 3 or 4).

2. Formula (3) 【Chemistry 2】 wherein Z is N and the further symbols and indices have the definitions given in claim 1. The compound according to claim 1 .

3. Formula (2a) or (3a) 【Chemistry 3】 wherein Z is N and the further symbols and indices have the definitions given in claim 1.

3. The compound according to claim 1 or 2, 4. The compound according to claim 1, wherein Ar 1 is selected from the group consisting of phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthalene, indole, benzofuran, benzothiophene, carbazole, dibenzofuran, dibenzothiophene, indenocarbazole, indolocarbazole, phenanthrene, triphenylene or a combination of two or three of these groups, each of which may be substituted by one or more R radicals.

5. Ar １ A process for the preparation of compounds according to any one of claims 1 to 4 by reacting a -functionalized dichloropyrimidine or -triazine with 1-dibenzofuran boronic acid or its ester or 1-dibenzothiophene boronic acid or its ester via Suzuki coupling.

6. A formulation comprising at least one compound according to any one of claims 1 to 4 and at least one further compound and / or solvent.

7. Use of a compound according to any one of claims 1 to 4 or a formulation according to claim 6 in an electronic device.

8. An electronic device comprising at least one compound according to any one of claims 1 to 4 or a formulation according to claim 6.

9. The electronic device according to claim 8, which is an organic electroluminescent device, characterized in that the compound according to any one of claims 1 to 4 is used in an emission layer as a matrix material for a phosphorescent emitter or an emitter exhibiting TADF (thermally activated delayed fluorescence) and / or in an electron transport layer and / or a hole blocking layer.

10. 10. An electronic device according to claim 9, characterized in that a compound according to any one of claims 1 to 4 is used in an emitting layer as matrix material for a phosphorescent emitter, said compound being used in combination with one or more further matrix materials selected from the group consisting of aromatic ketones, aromatic phosphine oxides, aromatic sulfoxides, aromatic sulfones, triarylamines, carbazole derivatives, indolocarbazole derivatives, indenocarbazole derivatives, azacarbazole derivatives, bipolar matrix materials, azaboroles, boronic esters, triazine derivatives, zinc complexes, diazasilol or traazasilol derivatives, diazaphosphole derivatives, bridged carbazole derivatives, triphenylene derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, wide band gap materials and / or phosphorescent compounds having an emission at a shorter wavelength than the actual emitter.

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