Materials for organic electroluminescent devices

Abstract

The present invention relates to dibenzofuran derivatives substituted with electron-deficient heteroaryl groups, and electronic devices, in particular organic electroluminescent devices, comprising said compounds as triplet matrix materials.

Description

[0001] The invention describes dibenzofuran and dibenzothiophene derivatives substituted by 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). OLEDs are still generally in need of improvement. The performance of phosphorescent OLEDs does not only depend on the triplet emitters used. More particularly, the other materials used, such as matrix materials, are also particularly important here. Therefore, improvements to these materials can also lead to significant improvements in the performance of OLEDs.

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

[0004] It has surprisingly been found that organic electroluminescent devices containing compounds of the formula (1) have high solubility and a high glass transition temperature and therefore very good processability from solution and, compared with the prior art, have an improved lifetime when used as matrix material for phosphorescent dopants.

[0005] Therefore, the present invention provides a compound of the following formula (1):

[0006]

[0007] The symbols and notations used are as follows:

[0008] Y 1 are the same or different and are O or S in each case;

[0009] Y 2 In each case the same or different and is NAr 2 , O, S or CR2;

[0010] Z is the same or different in each occurrence and is CR or N, provided that at least two Z are N;

[0011] Ar 1 ,Ar 2are identical or different in each case and are an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms and which may be substituted by one or more R groups;

[0012] R is identical or different in each case and is H, D, F, Cl, Br, I, N(Ar′)2, N(R 1 )2,OAr′,SAr′,CN,NO2,OR 1 , SR 1 ,COOR 1 ,C(=O)N(R 1 )2,Si(R 1 )3,B(OR 1 )2,C(=O)R 1 , P(=O)(R 1 )2,S(=O)R 1 , S(=O)2R 1 ,OSO2R 1 , a straight-chain 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 may in each case be replaced by one or more R 1 group, wherein one or more non-adjacent CH2 groups may be replaced by Si(R 1 )2. C=O、NR 1 , O, S or CONR 1 or having 5 to 60 aromatic ring atoms, preferably 5 to 40 aromatic ring atoms and in each case may be replaced by one or more R 1 Aromatic or heteroaromatic ring system substituted with a group; at the same time, two R groups together can also form a ring system;

[0013] Ar' is identical or different in each case and is an aromatic ring having 5 to 40 atoms and may be replaced by one or more R 1 At the same time, the two Ar' groups bonded to the same nitrogen atom can also be connected by a single bond or selected from N(R 1 )、C(R 1 )2. The bridges of O and S are connected to each other;

[0014] 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 , SR 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 may be replaced by one or more R 2 group, wherein one or more non-adjacent CH2 groups may be replaced by Si(R 2 )2. C=O、NR 2 , O, S or CONR 2 wherein one or more hydrogen atoms in the alkyl, alkenyl or alkynyl group may be replaced by D, F, Cl, Br, I or CN, or have 5 to 40 aromatic ring atoms and in each case may be replaced by one or more R 2 Aromatic or heteroaromatic ring system substituted with a group; at the same time, two or more R 1 The groups together can form an aliphatic ring system;

[0015] R 2 are in each case identical 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 hydrocarbon radical, in which one or more hydrogen atoms may also be replaced by F;

[0016] p, q, r are in each case identical or different and are 0, 1, 2 or 3;

[0017] s is identical or different in each case and is 0, 1, 2, 3 or 4.

[0018] Aryl groups in the context of the present invention contain 6 to 40 carbon atoms; heteroaryl groups in the context of the present invention contain 2 to 40 carbon atoms and at least one heteroatom, provided that the sum of carbon atoms and heteroatoms is at least 5. The heteroatoms are preferably selected from N, O and / or S. Aryl groups or heteroaryl groups are understood here to mean simple aromatic rings, i.e. benzene, or simple heteroaromatic rings, such as pyridine, pyrimidine, thiophene, etc., or condensed (annulated) aryl or heteroaryl groups, such as naphthalene, anthracene, phenanthrene, quinoline, isoquinoline, etc. In contrast, aromatic systems which are linked to one another by single bonds, such as biphenyl, are not referred to as aryl or heteroaryl groups, but as aromatic ring systems.

[0019] The aromatic ring system in the context of the present invention contains 6 to 40 carbon atoms in the ring system. The heteroaromatic ring system in the context of the present invention contains 2 to 39 carbon atoms and at least one heteroatom in the ring system, provided that the sum of carbon atoms and heteroatoms is at least 5. The heteroatom is preferably selected from N, O and / or S. The aromatic or heteroaromatic ring system in the context of the present invention should be understood to refer to the following system, which does not necessarily contain only aryl or heteroaryl groups, but wherein two or more aryl or heteroaryl groups can also be connected by non-aromatic units such as carbon, nitrogen or oxygen atoms. These should also be understood to refer to systems in which two or more aryl or heteroaryl groups are directly connected to each other, such as biphenyl, terphenyl, bipyridine or phenylpyridine. For example, systems such as fluorene, 9,9'-spirobifluorene, 9,9'-diarylfluorene, triarylamine, diaryl ether, stilbene, etc. should also be regarded as aromatic ring systems in the context of the present invention, and systems in which two or more aryl groups are connected, for example, by short alkyl groups are also the same. Preferred aromatic or heteroaromatic ring systems are simple aryl or heteroaryl groups and groups in which two or more aryl or heteroaryl groups are directly linked to one another, for example biphenyl or bipyridine, and also fluorene or spirobifluorene.

[0020] 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 straight-chain, branched and cyclic alkenyl and alkynyl groups, respectively.

[0021] In the context of the present invention, an aliphatic hydrocarbon or alkyl radical or an alkenyl or alkynyl radical which may contain 1 to 40 carbon atoms and in which individual hydrogen atoms or CH2 groups may also be replaced by the abovementioned radicals is preferably understood to mean a methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 2-methylbutyl, n-pentyl, sec-pentyl, neopentyl, cyclopentyl, n-hexyl, neohexyl, cyclohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, vinyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl or octynyl radical. An alkoxy radical having 1 to 40 carbon atoms OR 1 Preferably, these are to be understood as meaning methoxy, trifluoromethoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentoxy, sec-pentoxy, 2-methylbutoxy, n-hexyloxy, cyclohexyloxy, n-heptyloxy, cycloheptyloxy, n-octyloxy, cyclooctyloxy, 2-ethylhexyloxy, pentafluoroethoxy and 2,2,2-trifluoroethoxy. Thioalkyl radicals SR having 1 to 40 carbon atoms 1It is to be understood as meaning in particular methylthio, ethylthio, n-propylthio, isopropylthio, n-butylthio, isobutylthio, sec-butylthio, tert-butylthio, n-pentylthio, sec-pentylthio, n-hexylthio, cyclohexylthio, n-heptylthio, cycloheptylthio, n-octylthio, cyclooctylthio, 2-ethylhexylthio, trifluoromethylthio, pentafluoroethylthio, 2,2,2-trifluoroethylthio, vinylthio, propenylthio, butenylthio, pentenylthio, cyclopentenylthio, hexenylthio, cyclohexenylthio, heptenylthio, cycloheptenylthio, octenylthio, cyclooctenylthio, ethynylthio, propynylthio, butynylthio, pentynylthio, hexynylthio, heptynylthio or octynylthio. Generally speaking, the alkyl, alkoxy or thioalkyl groups according to the present invention can be linear, branched or cyclic, wherein one or more non-adjacent CH2 groups can be replaced by the above groups; in addition, one or more hydrogen atoms can also be replaced by D, F, Cl, Br, I, CN or NO2, preferably F, Cl or CN, more preferably F or CN.

[0022] has 5 to 40 aromatic ring atoms and can in each case be further replaced by the above R 2 An aromatic or heteroaromatic ring system which is substituted with a radical or a hydrocarbon radical and which can be attached to an aromatic or heteroaromatic system via any desired position is understood as meaning in particular radicals derived from benzene, naphthalene, anthracene, benzanthracene, phenanthrene, pyrene, lettuce, perylene, fluoranthene, tetracene, pentacene, benzopyrene, biphenyl, biphenylylidene, terphenyl, biphenylylidene, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, cis- or trans-indenofluorene ... trans-indenocarbazole, cis- or trans-indolocarbazole, trimerized indene, isotrimerized indene, spirotrimerized indene, spiroisotrimerized indene, 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, phenanthroline, azine, pyrazole, indazole, imidazole, benzimidazole, naphthimidazole, phenanthimidazole, pyridimidazole, pyrazimidazole, quinoxalineimidazole, Azoles, benzo Azoles, naphtho Azoles, anthracenes Azoles, phenanthracenes Azoles, Isopropylamine oxadiazole, 1,2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, hexaazaterphenylene, benzopyridazine, pyrimidine, benzopyrimidine, quinoxaline, 1,5-diazaanthracene, 2,7-diazapyrene, 2,3-diazapyrene, 1,6-diazapyrene, 1,8-diazapyrene, 4,5-diazapyrene, 4,5,9,10-tetraazaperylene, pyrazine, phenazine, phen Oxazine, phenothiazine, fluorescent red ring, naphthyridine, azacarbazole, benzocarboline, phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3- Oxadiazole, 1,2,4- Oxadiazole, 1,2,5- Oxadiazole, 1,3,4- oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, tetrazole, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine, purine, pteridine, indolizine and benzothiadiazole, or radicals derived from combinations of these systems.

[0023] The expression that two or more radicals together can 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, is understood to mean in particular that the two radicals are linked to one another by a chemical bond and formally eliminate two hydrogen atoms. This is illustrated by the following scheme:

[0024]

[0025] However, in addition, the above wording should also be understood to mean that if one of the two groups is hydrogen, the second group is bound to the bonding position of the hydrogen atom, thereby forming a ring. This will be illustrated by the following scheme:

[0026]

[0027] In a preferred embodiment of the present invention, the group incorporated into formula (1)

[0028]

[0029] is selected from the following groups (HetAr-1), (HetAr-2) and (HetAr-3):

[0030]

[0031] Among them, Ar 1 has the definition given above and the dotted bond indicates the linkage of this group within the compound of formula (1).

[0032] In a preferred embodiment of the present invention, all three Z groups are N, so the compound is preferably one of the following formula (2):

[0033]

[0034] The symbols and notations used therein have the definitions given above.

[0035] In another preferred embodiment of the present invention, Y 1 is O, so the compound is one of the following formulas (3):

[0036]

[0037] The symbols and notations used therein have the definitions given above.

[0038] In another preferred embodiment of the present invention, Y 2 It is NAr 2 , so the compound is one of the following formula (4):

[0039]

[0040] The symbols and notations used therein have the definitions given above.

[0041] When Y 2 It is NAr 2 When the carbazole group has at least two adjacent R groups that form a ring system with each other, the preferred carbazole group is selected from the following groups of formulae (CARB-1) to (CARB-6):

[0042]

[0043]

[0044] The structures described herein may each be substituted with one or more R groups on the carbazole and one or more R groups on the fused structure. 1 Groups are substituted, but preferably are unsubstituted, Y 3 is C(R 1 )2. NR 1 , O or S, preferably C(R 1 )2 or NR 1 And more preferably C(R 1 )2, and the structure is connected to dibenzofuran or dibenzothiophene via a dotted bond.

[0045] In another preferred embodiment of the present invention, all Z are N, and at the same time all Y 1 In another preferred embodiment of the present invention, all Z are N, and all Y 2 All are NAr 2 In another preferred embodiment of the present invention, all Y 1 are all O, and at the same time all Y 2 All are NAr 2 In a particularly preferred embodiment of the present invention, all Z are N and all Y1 are all O, and at the same time all Y 2 All are NAr 2 , so that the compound is one of the following formulas (5):

[0046]

[0047] The symbols and notations used therein have the definitions given above.

[0048] Contains Y 1 The linkage of the group, i.e. dibenzofuran or dibenzothiophene, is preferably via the 8-position, i.e. Y 1 In addition, 2 The linkage of the group is preferably at Y 2 =NAr 2 When the 3-bit is passed and the Y 2 =O or S, through 2 bits, that is, in Y 2 = CR2 in each case via Y 2 The counterpoint and is carried out via 2 positions.

[0049] The numbering of dibenzofuran and carbazole is shown below, with dibenzothiophene numbered similarly to dibenzofuran and fluorene numbered similarly to carbazole:

[0050]

[0051] Therefore, preferred embodiments of the compounds of formulae (1) to (5) are the following compounds of formulae (1a) to (5a):

[0052]

[0053]

[0054] The symbols and notations used therein have the definitions given above.

[0055] In another preferred embodiment of the compounds of formula (1), (2), (3), (4), (5), (1a), (2a), (3a), (4a) and (5a), p, q and r are in each case identical or different and are 0 or 1, and more preferably are 0. In yet another preferred embodiment of the compounds of formula (1), (2), (3), (4), (5), (1a), (2a), (3a), (4a) and (5a), s are in each case identical or different and are 0, 1 or 2, more preferably are 0 or 1, and most preferably are 0. Therefore, compounds of the following formula (6) are particularly preferred:

[0056]

[0057] The symbols used therein have the definitions given above and s is in each case identical or different and is 0 or 1.

[0058] A particularly preferred embodiment is the compound of the following formula (6a):

[0059]

[0060] The symbols used therein have the definitions given above and s is in each case identical or different and is 0 or 1, preferably 0.

[0061] In another preferred embodiment of the present invention, Ar 1 , ie the substituents on the triazine or pyrimidine, are in each case identical or different and are aromatic or heteroaromatic ring systems having 6 to 30 aromatic ring atoms and which may be substituted by one or more R groups. More preferably, Ar 1 are identical or different in each case and are an aromatic or heteroaromatic ring system, in particular an aromatic ring system, which has 6 to 24 aromatic ring atoms, in particular 6 to 13 aromatic ring atoms, and which may be substituted by one or more R groups, preferably by nonaromatic R groups. 1 In the case of a heteroaryl group, in particular a triazine, pyrimidine, quinazoline or carbazole, preference may also be given to aromatic or heteroaromatic substituents R on the heteroaryl group.

[0062] Suitable aromatic or heteroaromatic ring systems Ar 1 are in each case identical 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 attached via the 1, 2, 3 or 4 position, spirobifluorene which may be attached via the 1, 2, 3 or 4 position, naphthalene which may be attached via the 1 or 2 position, indole, benzofuran, benzothiophene, carbazole which may be attached via the 1, 2, 3 or 4 position, dibenzofuran which may be attached via the 1, 2, 3 or 4 position, dibenzothiophene which may be attached via the 1, 2, 3 or 4 position, indenocarbazole, indolocarbazole, phenanthrene, terphenylidene or a combination of two or three of these radicals, each of which may be substituted by one or more R radicals, preferably by nonaromatic R radicals. When Ar 1 In the case of a heteroaryl group, in particular a triazine, pyrimidine, quinazoline or carbazole, preference may also be given to aromatic or heteroaromatic R groups on the heteroaryl group.

[0063] Here is Ar 1 Preference is given to groups which are identical or different in each case and are selected from the following formulae Ar-1 to Ar-81:

[0064]

[0065]

[0066]

[0067]

[0068]

[0069]

[0070] wherein R is as defined above, the dashed bond represents the bond to the heteroaryl group, and in addition:

[0071] A 1 are the same or different in each case and are CR2, NR, O or S;

[0072] Ar 3 are identical or different in each case and are a divalent aromatic or heteroaromatic ring system having 6 to 18 aromatic ring atoms and which may be substituted in each case by one or more R groups;

[0073] n is 0 or 1, where n=0 means there is no bond A at this position 1 groups, but the R groups are bonded to the corresponding carbon atoms;

[0074] m is 0 or 1, where m=0 means that there is no Ar 3 The group and the corresponding aromatic or heteroaromatic group are directly bonded to the triazine or pyrimidine group in formula (1).

[0075] Ar 1 The group is selected from 1-dibenzofuranyl, i.e., wherein A 1 =O and m=0, a radical of the formula Ar-16, phenyl-1-dibenzofuranyl, i.e., wherein A 1 =O, m=1 and Ar 3 = Radicals of the formula Ar-16 which are p-phenylene, phenyl, o-biphenyl, m-biphenyl, p-biphenyl, quaterphenyl, p-tert-butylphenyl, naphthyl, fluorenyl (especially 9,9-dimethyl-2-fluorenyl) and 1-dibenzothienyl.

[0076] In another preferred embodiment of the present invention, Ar 2 , that is, when Y 2 =NAr 2 The substituents on the carbazole are in each case identical or different and are aromatic or heteroaromatic ring systems having 6 to 30 aromatic ring atoms and which may be substituted by one or more R groups. More preferably, Ar2 are identical or different in each case and are an aromatic or heteroaromatic ring system, in particular an aromatic ring system, which has 6 to 24 aromatic ring atoms, in particular 6 to 13 aromatic ring atoms, and may be substituted by one or more preferably nonaromatic R radicals. 2 In the case of a heteroaryl group, in particular a triazine, pyrimidine, quinazoline or carbazole, preference may also be given to aromatic or heteroaromatic substituents R on the heteroaryl group.

[0077] Suitable aromatic or heteroaromatic ring systems Ar 2 are in each case identical 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 attached via the 1, 2, 3 or 4 position, spirobifluorene which may be attached via the 1, 2, 3 or 4 position, naphthalene which may be attached via the 1 or 2 position, indole, benzofuran, benzothiophene, carbazole which may be attached via the 1, 2, 3 or 4 position, dibenzofuran which may be attached via the 1, 2, 3 or 4 position, dibenzothiophene which may be attached via the 1, 2, 3 or 4 position, indenocarbazole, indolocarbazole, phenanthrene, terphenylidene or a combination of two or three of these radicals, each of which may be substituted by one or more R radicals, preferably by nonaromatic R radicals. When Ar 2 In the case of a heteroaryl group, in particular a triazine, pyrimidine, quinazoline or carbazole, preference may also be given to aromatic or heteroaromatic R groups on the heteroaryl group.

[0078] Here is Ar 2 Preference is given to radicals which are identical or different in each case and are selected from the abovementioned formulae Ar-1 to Ar-81.

[0079] Ar 2 The group is selected from 1-dibenzofuranyl, i.e., wherein A 1 =O and m=0, a radical of the formula Ar-16, phenyl-1-dibenzofuranyl, i.e., wherein A 1 =O, m=1 and Ar 3 = a group of formula Ar-16 of p-phenylene group, phenyl group, o-biphenyl group, m-biphenyl group, p-biphenyl group, o-p-terphenyl group, quaterphenyl group, p-tert-butylphenyl group, terphenylidene group and N-phenyl-3-carbazolyl group.

[0080] In a preferred embodiment of the invention, R is identical or different in each case and is selected from 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 may be replaced by one or more R 1 substituted with, but preferably unsubstituted with, groups and in which one or more non-adjacent CH2 groups may be replaced by O, or having 6 to 30 aromatic ring atoms and in each case by one or more R 1 At the same time, the two R groups together can also form an aliphatic, aromatic or heteroaromatic ring system. More preferably, R is in each case identical or different and is selected from 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, wherein the alkyl group can be replaced by one or more R in each case. 1 substituted, but preferably unsubstituted, or having 6 to 24 aromatic ring atoms and in each case may be replaced by one or more R 1 Group substituted, preferably by non-aromatic R 1 Most preferably, R is identical or different in each case and is selected from H or a ring having 6 to 24 aromatic ring atoms, preferably 6 to 18 aromatic ring atoms, more preferably 6 to 13 aromatic ring atoms and can be replaced by one or more R in each case. 1 Group substituted, preferably by non-aromatic R 1 Aromatic or heteroaromatic ring systems substituted with radicals.

[0081] In another preferred embodiment of the present invention, Ar′ is a ring having 6 to 30 aromatic ring atoms and can be replaced by one or more R 1 In a particularly preferred embodiment of the present 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 can be replaced by one or more preferably non-aromatic R 1 Aromatic or heteroaromatic ring systems substituted with radicals.

[0082] Suitable aromatic or heteroaromatic ring systems R or Ar′ are selected from 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 attached via the 1-, 2-, 3- or 4-position, spirobifluorene which may be attached via the 1-, 2-, 3- or 4-position, naphthalene which may be attached via the 1- or 2-position, indole, benzene indolecarbazole, indolecarbazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, quinazoline, benzimidazole, phenanthrene, terphenylene or a combination of two or three of these groups, each of which may be substituted by one or more non-aromatic R 1 When R or Ar′ is a heteroaryl group, especially triazine, pyrimidine or quinazoline, it is also preferred that the aromatic or heteroaromatic R on the heteroaryl group 1 Group.

[0083] The R groups here (when they are aromatic or heteroaromatic ring systems), or Ar', are preferably selected from the following groups of formulae R-1 to R-81:

[0084]

[0085]

[0086]

[0087]

[0088]

[0089] Where R 1 Having the definitions given above, the dashed bonds represent the bonds to the basic skeleton in formula (1) or to Ar 1 or Ar 2 A bond to a nitrogen atom in a N(Ar′)2 group, and in addition:

[0090] A 1 are the same or different in each case and are C(R 1 )2. NR 1 , O or S;

[0091] Ar 3 are identical or different in each case and have 6 to 18 aromatic ring atoms and can be replaced by one or more R 1a divalent aromatic or heteroaromatic ring system substituted with a radical;

[0092] n is 0 or 1, where n=0 means there is no bond A at this position 1 group, but R 1 The groups are bonded to the corresponding carbon atoms;

[0093] m is 0 or 1, where m=0 means that there is no Ar 3 The group and the corresponding aromatic or heteroaromatic group is directly bonded to the basic skeleton in formula (1) or in a preferred embodiment, or is bonded to the nitrogen atom in the N(Ar′)2 group; provided that when these groups are embodiments of Ar′, for structures (R-12), (R-17), (R-21), (R-25), (R-26), (R-30), (R-34), (R-38) and (R-39), m=1.

[0094] When the above Ar-1 to Ar-81 groups (for Ar 1 or Ar 2 ) or R-1 to R-81 groups (for R or Ar') have two or more A 1 Groups, these viable options include from A 1 In this case, the preferred embodiment is one of A 1 The group is NR or NR 1 And another A 1 The group is C(R)2 or C(R 1 )2 or two A 1 The groups are all NR or NR 1 Or two A 1 In a particularly preferred embodiment of the present invention, in the case of two or more A 1 Ar 1 ,Ar 2 , R or Ar' groups, at least one A 1 The group is C(R)2 or C(R 1 )2 or NR or NR 1 .

[0095] When A 1 is NR or NR 1 When the substituent R or R 1 Preferably, the aromatic ring has 5 to 24 atoms and may be replaced by one or more R 1 or R 2 In a particularly preferred embodiment, the R or R 1The substituents are identical or different in each case and are aromatic or heteroaromatic ring systems having 6 to 24 aromatic ring atoms, preferably 6 to 12 aromatic ring atoms, and without any fused aryl or heteroaryl groups in which two or more aromatic or heteroaromatic 6-membered ring groups are fused directly to one another, and may in each case also be replaced by one or more R 1 or R 2 Particularly preferred are phenyl, biphenyl, terphenyl and quaterphenyl having the bonding modes listed above for Ar-1 to Ar-11 or R-1 to R-11, wherein these structures may be replaced by one or more R 1 or R 2 The group is substituted, but is preferably unsubstituted.

[0096] When A 1 Is C(R)2 or C(R 1 )2, the substituent R or R bonded to the carbon atom 1 are preferably identical or different in each case and are a straight-chain alkyl radical having 1 to 10 carbon atoms, or a branched or cyclic alkyl radical having 3 to 10 carbon atoms, or a radical having 5 to 24 aromatic ring atoms and which may also be replaced by one or more R 1 or R 2 Most preferably, R or R 1 is a methyl group or a phenyl group. In this case, R or R 1 The groups together can also form a ring system, giving rise to a spiro ring system.

[0097] In another preferred embodiment of the present invention, R 1 are identical or different in each case and are selected from H, D, F, CN, OR 2 , a straight-chain 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 may in each case be replaced by one or more R 2 or having 6 to 30 aromatic ring atoms and in each case being replaced by one or more R 2 Aromatic or heteroaromatic ring system substituted with a group; at the same time, two or more R 1 The groups together can form an aliphatic ring system. In a particularly preferred embodiment of the present invention, R 1 are in each case identical or different and are selected from H, 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, wherein the alkyl group may be replaced by one or more R2 or 6 to 24 aromatic ring atoms, preferably 6 to 18 aromatic ring atoms, more preferably 6 to 13 aromatic ring atoms, and may in each case be replaced by one or more R 2 The radicals are substituted but preferably unsubstituted aromatic or heteroaromatic ring systems.

[0098] In another preferred embodiment of the present invention, R 2 are in each case identical or different and are H, F, an alkyl radical having 1 to 4 carbon atoms or an aryl radical having 6 to 10 carbon atoms, which may be substituted by an alkyl radical having 1 to 4 carbon atoms, but is preferably unsubstituted.

[0099] The above preferred features may appear alone or together. It is preferred when the above preferred features appear together.

[0100] Examples of suitable compounds of the invention are the structures shown below:

[0101]

[0102]

[0103]

[0104]

[0105]

[0106] The compounds of the present 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 generally shown in Scheme 1 below, where the symbols and indices used have the definitions given above. The compounds of the present invention can be prepared herein by Ar 1 Functionalized dichloropyrimidines or dichlorotriazines are prepared by reaction with 1-dibenzofuranboronic acid or its esters in a Suzuki coupling. The reaction can be carried out in two steps as shown in Scheme 1, or in one step when using the same substituted 1-dibenzofuranboronic acid or 1-dibenzofuranboronic ester. The Suzuki coupling can be carried out in an aprotic solvent such as toluene, dibenzofuranboronic acid or 1-dibenzofuranboronic acid. The reaction mixture is carried out in a reactor (e.g., in alkane, DHF, DMF, DMSO) or in the presence of a protic solvent (e.g., alcohol, water). The catalyst used is usually a Pd catalyst or a Pd compound (palladium acetate, Pd-dba, etc.) and a phosphine (triphenylphosphine, tri-o-tolylphosphine, S-Phos, X-Phos, BINAP, DPPF, Xanth-Phos, etc.). The base used for the coupling reaction includes an inorganic salt (sodium carbonate, potassium carbonate or cesium carbonate, sodium phosphate, potassium phosphate or cesium phosphate, sodium fluoride, potassium fluoride or cesium fluoride, sodium borate, potassium borate or cesium borate) and a hydrate thereof.

[0107] Solution 1

[0108]

[0109] Although the compounds of the invention can also be processed by vapor deposition under reduced pressure, the main object of the invention is to provide compounds for processing from the liquid phase, for example by spin coating or by printing methods. For this purpose, preparations of the compounds of the invention are needed. These preparations can be, for example, solutions, dispersions or emulsions, preferably solutions. For this purpose, a mixture of two or more solvents can be preferably used. Suitable and preferred solvents are, for example, toluene, anisole, o-xylene, m-xylene or p-xylene, methyl benzoate, mesitylene, tetralin, o-dimethoxybenzene, THF, methyl-THF, THP, chlorobenzene, dimethoxybenzene, alkane, phenoxytoluene, especially 3-phenoxytoluene, (-)-fenchone, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, 1-methylnaphthalene, 2-methylbenzothiazole, 2-phenoxyethanol, 2-pyrrolidone, 3-methylanisole, 4-methylanisole, 3,4-dimethylanisole, 3,5-dimethylanisole, acetophenone, α-terpineol, benzothiazole, benzyl Butyl ester, cumene, cyclohexanol, cyclohexanone, cyclohexylbenzene, decalin, dodecylbenzene, ethyl benzoate, indane, NMP, p-cymene, phenethyl ether, 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-isopropylbenzene Propylnaphthalene, 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, menthyl isovalerate, cyclohexyl hexanoate, alkoxy-substituted ethyl benzoates, especially 2-methoxyethyl benzoate and 4-methoxyethyl benzoate, alkoxy substituted ethyl benzoate, 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.

[0110] Therefore, the present invention also provides a preparation comprising at least one of the compounds of this invention and at least one other compound. The other compound can be, for example, a solvent, especially a mixture of one or these solvents in the above-mentioned solvent. The other compound can alternatively be at least one other organic or inorganic compound, for example a luminescent compound and / or other host material, which is also used in electronic devices. Suitable luminescent compounds and other host materials relevant to organic electroluminescent devices are listed later. This other compound can also be polymeric.

[0111] The compounds of the present invention are suitable for electronic devices, especially organic electroluminescent devices. Therefore, the present invention also provides the use of the compounds of the present invention in electronic devices, especially organic electroluminescent devices.

[0112] The present invention further provides electronic devices comprising at least one compound according to the invention.

[0113] An electronic device in the context of the present invention is a device comprising at least one layer comprising at least one organic compound. The component may also comprise an inorganic material or a layer formed entirely of an inorganic material. The electronic device is preferably selected from the group consisting of an organic electroluminescent device (OLED), an organic integrated circuit (O-IC), an organic field effect transistor (O-FET), an organic thin film transistor (O-TFT), an organic light emitting transistor (O-LET), an organic solar cell (O-SC), an organic dye-sensitized solar cell (DSSC), an organic optical detector, an organic photoreceptor, an organic field quenching device (O-FQD), a light emitting electrochemical cell (LEC), an organic laser diode (O-laser) and an organic plasma light emitting device, but preferably an organic electroluminescent device (OLED), more preferably a phosphorescent OLED.

[0114] The organic electroluminescent device comprises a cathode, an anode and at least one luminescent layer. In addition to these layers, it may also include 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 in each case. An intermediate layer with an exciton blocking function may also be introduced, for example, between two luminescent layers. However, it should be noted that each of these layers does not necessarily have to exist. In this case, the organic electroluminescent device may include a luminescent layer, or it may include multiple luminescent layers. If multiple luminescent layers are present, these luminescent layers preferably have a total of several luminescent peaks between 380nm and 750nm, so that the overall result is white luminescence; in other words, a variety of luminescent compounds that can emit fluorescence or emit phosphorescence are used in the luminescent layer. Particularly preferred is a system with three luminescent layers, wherein the three layers display blue, green and orange or red luminescence. The organic electroluminescent device of the present invention may also be a series OLED, especially a white-light OLED.

[0115] The compounds of the present invention according to the above-mentioned embodiments can be used in different layers. Preferably, the organic electroluminescent device containing the compound of formula (1) or the above-mentioned preferred embodiment as a phosphorescent light emitter or a light emitter showing TADF (thermally activated delayed fluorescence), especially a host material of a phosphorescent light emitter, in the luminescent layer. In this case, the organic electroluminescent device may include a luminescent layer, or it may include multiple luminescent layers, wherein at least one luminescent layer includes at least one compound of the present invention as a host material. In addition, the compounds of the present invention may also be used in an electron transport layer and / or a hole blocking layer.

[0116] When the compound of 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 in the context of the present invention is understood to mean the emission from excited states with a higher spin multiplicity (i.e. spin state>1), especially from excited triplet states. In the context of the present application, all luminescent complexes with transition metals or lanthanides, especially all iridium, platinum and copper complexes, are to be regarded as phosphorescent compounds.

[0117] Examples of the above-mentioned luminophores can be found in 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、WO2011 / 066898、WO 2011 / 157339、WO 2012 / 007086、WO 2014 / 008982、WO 2014 / 023377、WO2014 / 094961、WO 2014 / 094960、WO 2015 / 036074, WO 2015 / 104045, WO 2015 / 117718, WO2016 / 015815, WO 2016 / 124304, WO 2017 / 032439, WO 2018 / 011186 and WO 2018 / 041769、WO2019 / 020538、WO 2018 / 178001, WO 2019 / 115423 or WO 2019 / 158453. In general, all phosphorescent complexes used in phosphorescent OLEDs according to the prior art and known to the person skilled in the art in the field of organic electroluminescence are suitable, and the person skilled in the art will be able to use further phosphorescent complexes without inventive step.

[0118] Examples of the phosphorescent dopant are listed below.

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125]

[0126]

[0127]

[0128]

[0129]

[0130] When the organic electroluminescent device is produced from solution, the mixture of the whole host and the luminescent compound containing the compounds of the present invention contains between 99% by weight and 1% by weight, preferably between 97% by weight and 50% by weight, more preferably between 96% by weight and 60% by weight and especially preferably between 95% by weight and 75% by weight of the host containing the compounds of the present invention. Accordingly, based on the overall mixture of luminophore and all matrix materials, the mixture contains between 1% by weight and 99% by weight, preferably between 3% by weight and 50% by weight, more preferably between 5% by weight and 40% by weight and especially preferably between 5% by weight and 25% by weight of the luminophore.

[0131] As described in more detail below, the host material can also be a mixture of two or more materials, at least one of which is a compound of the present invention. Based on all components of the luminescent layer, the proportion of the host material of the present invention, i.e., the compound of formula (1) or the preferred embodiment, is between 99% by weight and 1% by weight, preferably between 95% by weight and 10% by weight, more preferably between 80% by weight and 20% by weight and most preferably between 70% by weight and 25% by weight.

[0132] When the organic electroluminescent device is produced by vapor deposition, based on the overall mixture of luminophore and matrix material, the mixture of the compound of the present invention and the luminescent compound contains between 99% by volume and 1% by volume, preferably between 98% by volume and 10% by volume, more preferably between 97% by volume and 60% by volume and especially between 95% by volume and 80% by volume of the compound of the present invention. Accordingly, based on the overall mixture of luminophore and matrix material, the mixture contains between 1% by volume and 99% by volume, preferably between 2% by volume and 90% by volume, more preferably between 3% by volume and 40% by volume and especially between 5% by volume and 20% by volume of the luminophore.

[0133] A further preferred embodiment of the present invention is the use of the compounds according to the invention as matrix material for phosphorescent emitters in combination with a further matrix material. Suitable matrix materials which can be used in combination with the compounds according to the invention are aromatic ketones, aromatic phosphine oxides or aromatic sulfoxides or sulfones, for example according to WO 2004 / 013080, WO 2004 / 093207, WO 2006 / 005627 or WO 2010 / 006680; triarylamines, carbazole derivatives, for example CBP (N,N-biscarbazolylbiphenyl) or the carbazole derivatives disclosed in WO 2005 / 039246, US 2005 / 0069729, JP 2004 / 288381, EP 1205527, WO 2008 / 086851 or WO 2013 / 041176; indolocarbazole derivatives, for example according to WO 2007 / 063754 or WO 2008 / 056746; indenocarbazole derivatives, for example according to WO 2010 / 136109, WO 2011 / 000455, WO 2013 / 041176 or WO 2013 / 056776; azacarbazole derivatives, for example according to EP 1617710, EP 1617711, EP 1731584, JP2005 / 347160; bipolar matrix materials, for example according to WO 2007 / 137725; silanes, for example according to WO 2005 / 111172; borazolidines or boric acid 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 WO2011 / 060877; zinc complexes, for example according to EP 652273 or WO 2009 / 062578; siladiazacyclopentane or siladiazacyclopentane derivatives, for example according to WO 2010 / 054729; phosphodiazacyclopentane derivatives, for example according to WO2010 / 054730; bridged carbazole derivatives, for example according to WO 2011 / 042107, WO 2011 / 060867, WO 2011 / 088877 and WO 2012 / 143080; terphenylidene 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 WO2017 / 148565; or a dibenzothiophene derivative.

[0134] It is likewise possible for further phosphorescent emitters which emit at a shorter wavelength than the actual emitter to be present in the mixture as cohosts. For example, when a red-emitting OLED is to be constructed, in addition to a red phosphorescent emitter, a green phosphorescent emitter can also be used.

[0135] Furthermore, it is feasible to use compounds which do not significantly participate in charge transport (if at all) as additional "wide bandgap" matrix materials, as described, for example, in WO 2010 / 108579, WO 2016 / 184540 or the as yet unpublished application EP19152285.3. In a preferred embodiment of the invention, the wide bandgap material is a hydrocarbon, i.e. does not contain heteroatoms.

[0136] A wide bandgap matrix material in the context of the present invention is a material which, in the light-emitting layer mixture used, has a HOMO which is at least 0.2 eV lower than the highest HOMO of all other materials represented in the mixture (emitter and host material) and a LUMO which is at least 0.2 eV higher than the lowest LUMO of all other materials represented in the mixture (emitter and host material).

[0137] The energy values ​​reported are related to the isolated compounds and were determined as described below.

[0138] The HOMO (highest occupied molecular orbital) and LUMO (lowest unoccupied molecular orbital) energy and triplet energy level of the material are determined via quantum chemical calculations. For this purpose, in this example, the "Gaussian09, Rev. D.01" software package (Gaussian) is used. If the same method has been implemented therein, other software packages can be used alternatively. In order to calculate organic substances without metals, the geometry is first optimized by the semi-empirical method AM1 (Gaussian input line "#AM1opt") with a charge of 0 and a multiplicity of 1. Subsequently, based on the optimized geometry, (single point) energy calculations are realized for the electronic ground state and triplet energy level. This is performed using the TDDFT (time-dependent density functional theory) method B3PW91 with a 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 geometry was optimized by the Hartree-Fock method and the LanL2MB basis set (Gaussian input line "#HF / LanL2MB opt") (charge 0, multiplicity 1). Energy calculations were performed similarly to organic substances as described above, except that the "LanL2DZ" basis set was used for metal atoms and the "6-31G(d)" basis set was used for ligands (Gaussian input line "#B3PW91 / genpseudo=lanl2 td=(50-50, nstates=4)"). The HOMO as the last orbital occupied by two electrons (αocc. eigenvalue) and the LUMO as the first unoccupied orbital (αvirt. eigenvalue) were obtained from the energy calculations in Hartree units (HEh and LEh). This was used to determine the HOMO and LUMO values ​​(in electron volts), which were calibrated by cyclic voltammetry measurements as follows:

[0139] LUMO(eV)=(1.0658*LEh*27.212)-0.5049

[0140] HOMO(eV)=(0.8308*HEh*27.212)-1.1180

[0141] In the context of this application, these values ​​are regarded as the HOMO and LUMO of the material.

[0142] Examples of suitable wide bandgap materials are the structures shown in the following table:

[0143]

[0144]

[0145] Furthermore, the compounds of the present invention may be used in a hole blocking layer and / or an electron transport layer.

[0146] In other layers of the organic electroluminescent device of the present invention, any material commonly used according to the prior art can be used. Therefore, those skilled in the art can use any material known for organic electroluminescent devices in combination with formula (1) or the compounds of the present invention according to the preferred embodiments without paying creative effort.

[0147] Furthermore, preference is given to organic electroluminescent devices which are characterized in that one or more layers are applied by a sublimation process. In this case, in a vacuum sublimation system, the organic electroluminescent device is applied at a temperature of less than 10 -5 mbar, preferably less than 10 -6 The material is applied by vapor deposition at an initial pressure of 10 mbar. However, the initial pressure can also be lower or higher, for example less than 10 -7 millibar.

[0148] Preference is likewise given to organic electroluminescent devices which are characterized in that one or more layers are applied by the OVPD (organic vapor phase deposition) method or by means of carrier gas sublimation. -5 The material is applied at a pressure between mbar and 1 bar. A special example of this method is the OVJP (Organic Vapor Jet Printing) method, in which the material is applied directly via a nozzle and is thus structured (eg MS Arnold et al., Appl. Phys. Lett. 2008, 92, 053301).

[0149] Additionally 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), screen printing, flexographic printing, lithography or nozzle printing. It has been found that the compounds according to the invention are particularly well suited for processing from solution.

[0150] Furthermore, hybrid methods are possible in which, for example, one or more layers are applied from solution and one or more further layers are applied by vapor deposition. For example, the light-emitting layer can be applied from solution and the electron-transporting layer by vapor deposition.

[0151] 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 comprising the compounds according to the invention.

[0152] The compounds of the present invention are very suitable for processing from solution. At the same time, they have very good solubility and high glass transition temperature in standard organic solvents. Compared with the compounds of the prior art, especially with compounds containing only one dibenzofuran-carbazole unit on triazine or with compounds in which the triazine is replaced by two or more 1-dibenzofuran groups but only one dibenzofuran group is replaced by a carbazole group, the compounds of the present invention are used as the matrix material of phosphorescent light emitters in organic electroluminescent devices produced from solution, resulting in a significant improvement in the life of the organic electroluminescent device. At the same time, the other properties of the organic electroluminescent device, especially efficiency and voltage, are comparable or better.

[0153] The present invention will now be illustrated in detail by the following examples without intending to limit the invention thereby. Example

[0154] Unless otherwise stated, the following syntheses were carried out in anhydrous solvents under a protective gas atmosphere. Solvents and reagents can be purchased, for example, from Sigma-ALDRICH or ABCR. The corresponding numbers in square brackets or the numbers quoted for individual compounds relate to the CAS numbers of the compounds known from the literature.

[0155] Phase 1: BB-1a

[0156]

[0157] 100 g (26 mmol) of 1-bromo-8-iododibenzofuran (CAS: 1822311-11-4), 92.4 g (32 mmol) of (9-phenyl-9H-carbazole-3-yl)boric acid, 85.2 g (61 mmol) of potassium carbonate and 15.5 g (13 mmol) of tetrakis(triphenylphosphine)palladium(0) were mixed in 1 1 of ethylene glycol dimethyl ether / water (3:1) and heated under reflux overnight. The mixture was allowed to reach room temperature and the precipitate was filtered off and washed with water and ethanol. Yield: 86 g (176 mmol; 66%).

[0158] The following compounds can be synthesized similarly:

[0159]

[0160]

[0161] Phase 2: BB-2a

[0162]

[0163] 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]dioxaborolane], 52.4 g (530 mmol) of potassium acetate and 2.8 g (12 mmol) of palladium acetate were mixed in 11 DMF and stirred at 100° C. After 24 hours, the reaction mixture was cooled to room temperature and the mixture was concentrated to one third under reduced pressure. Water was added and the precipitated solid was filtered off, washed with water, ethanol and heptane and further purified by filtration over silica using THF as eluent. The product was obtained by removing the solvent under reduced pressure. Yield: 58.2 g (109 mmol; 62%).

[0164] The following compounds can be synthesized similarly:

[0165]

[0166]

[0167]

[0168] Phase 3: BB-3a

[0169]

[0170] 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 (iodine is added to start the Grignard reaction), and the mixture is heated at reflux for 2 hours. 350 ml of THF are added, and the reaction mixture is allowed to reach 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 stirred overnight at room temperature. The mixture is then cooled to 0°C and 8 ml of hydrochloric acid (1 M) is added dropwise. The mixture is stirred for 1 hour, and then 400 ml of water are added. The organic phase is separated 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%).

[0171] Stage 4 (symmetric): Compound 1

[0172]

[0173] 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 were mixed in 500 ml of water / THF (1:3) and stirred at 70°C overnight. Subsequently, the reaction mixture was allowed to reach room temperature, ethyl acetate was added and the phases were separated. The organic phase was washed with water and the aqueous phase was extracted with ethyl acetate. The combined organic phases were concentrated under reduced pressure and purified by flash chromatography (heptane / THF 10:1). The product was purified by recrystallization from heptane / toluene. By sublimation (430℃, 10 -4 Further purification was achieved by 4% paraformaldehyde (0.1 mmol / l) at 400 mbar. Yield: 22.6 g (21.28 mmol; 28%).

[0174] The following compounds can be synthesized similarly:

[0175]

[0176]

[0177]

[0178]

[0179]

[0180] Stage 5 (asymmetric): BB-4a

[0181]

[0182] 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 reach 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). Yield: 30 g (43.5 mmol; 58%).

[0183] The following compounds can be synthesized similarly:

[0184]

[0185] Stage 6 (asymmetric): Compound 1.1

[0186]

[0187] 29 g (42.1 mmol) of 3-[9-(4-chloro-6-dibenzofuran-1-yl-[1,3,5]triazine-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 were mixed in 500 ml of water / THF (1:3) and stirred at 70°C overnight. The reaction mixture was allowed to reach room temperature, ethyl acetate was added and the phases were separated. The organic phase was washed with water and the aqueous phase was extracted with ethyl acetate. The combined organic phases were concentrated under reduced pressure. The product was purified by flash chromatography (heptane / THF 10:1) and then by recrystallization (heptane / toluene). Yield: 20.6 g (16.0 mmol; 38%).

[0188] In a similar manner, the following compounds can be synthesized:

[0189]

[0190]

[0191] Device Examples from Solution Processing: Production of OLEDs

[0192] In the literature, for example in WO 2004 / 058911, there are many descriptions of the production of OLEDs by vapor deposition. For example, the production of solution-based OLEDs is described in detail in WO 2004 / 037887 and WO 2010 / 097155. The following examples combine the two production processes so that the layers up to and including the luminescent layer are processed from solution and the subsequent layers (hole blocking layer / electron transport layer) are applied by vapor deposition under reduced pressure. For this purpose, the general method described above is matched with the situation described here (layer thickness variation, materials) and combined as follows.

[0193] The construction of the OLED used is as follows:

[0194] - substrate,

[0195] -ITO (50nm),

[0196] - Buffer (20 nm),

[0197] - Hole transport layer (HTL, 20 nm),

[0198] -Emitting layer (EML, 50nm),

[0199] -Electron transport layer (ETL, 20nm),

[0200] -Electron injection layer (EIL, 3nm),

[0201] -Al cathode (100nm).

[0202] The substrates used are glass plates coated with structured ITO (indium tin oxide) with a thickness of 50 nm. For better processing, they are coated with a buffer PEDOT:PSS (poly (3,4-ethylenedioxy-2,5-thiophene): polystyrene sulfonate) from Heraeus Precious Metals GmbH & Co.KG). Spin coating is achieved from water under air. The layers are subsequently baked at 180°C for 10 minutes. A hole transport layer and a light-emitting layer are applied to the glass plates thus coated. The hole transport layer is a polymer of the structure shown in Table 1, which can be synthesized according to WO 2010 / 097155. The polymer is dissolved in toluene so that the solution generally has a solid content of about 5 g / l, at which point, as is the case here, a typical layer thickness of 20 nm for the device is achieved by spin coating. The layers are spin-coated in an inert gas atmosphere (nitrogen in this case) and baked at 220°C for 30 minutes.

[0203] The emitting layer always consists of at least one matrix material (host material) and a luminescent dopant (luminophore). Details given in the form of H1 (92%): D1 (8%) mean here that the material H1 is present in the emitting layer in a weight proportion of 92% and the dopant D1 is present in a weight proportion of 8%. The mixture for the emitting layer is dissolved in toluene. The typical solid content of such a solution is about 14 g / l, as here, a typical layer thickness of 50 nm for the device is achieved by spin coating. The layer is spin-coated in an inert gas atmosphere (nitrogen in this case) and baked for 10 minutes. The materials used are shown in Table 1. The corresponding composition of the emitting layer, the EML layer thickness and its baking temperature are shown in Table 2.

[0204] The materials for the electron transport layer and the cathode are applied by thermal vapor deposition in a vacuum chamber. For example, the electron transport layer can consist of more than one material, which are added to each other in a specific volume ratio by co-evaporation. The details given in the form of ETM:EIM (50%:50%) mean that the ETM and EIM materials are present in the layer in a volume ratio 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 of 3 nm of EIM material. Both materials are shown in Table 1. The end layer is a cathode layer of aluminum with a layer thickness of 100 nm.

[0205] The OLEDs were characterized in a standard manner. For this purpose, the electroluminescence spectrum was recorded, the current efficiency (measured in cd / A) and the external quantum efficiency (EQE, measured in percent) were calculated as a function of the luminous density from the current-voltage-luminous density characteristic (IUL characteristic) exhibiting Lambertian luminescence, and finally the lifetime of the component was determined. 2 The electroluminescence spectra were recorded at a luminous density of 1000 cd / m and the CIE 1931 x and y color coordinates were calculated from them. 2 The parameter EQE below refers to the value at 1000cd / m 2 External quantum efficiency at working luminous density. At 4000cd / m 2 The lifespan under LT95 is 4000cd / m 2 The initial brightness dropped by 5% to 3800cd / m 2 The data for various OLEDs are collated in Table 3.

[0206]

[0207]

[0208]

[0209]

[0210]

[0211]

[0212] The results in Table 3 show that not only a slight improvement in external quantum efficiency can be achieved, but also a significant improvement in lifetime. The discovered structures are therefore suitable as hosts for processing from solution and yield excellent performance data.

Claims

1. A compound of formula (2), The symbols and notations used are as follows: Y 1 are the same or different and are O or S in each case; Y 2 In each case the same or different and is NAr 2 or O; Ar 1 ,Ar 2 are identical or different in each case and are an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms and which may be substituted by one or more R groups; R is identical or different in each case and is H, D, a straight-chain alkyl group having 1, 2, 3 or 4 carbon atoms, wherein the alkyl group may be replaced by one or more R in each case. 1 or have 5 to 13 aromatic ring atoms and may be substituted by one or more R 1 group-substituted aromatic or heteroaromatic ring systems; R 1 are the same or different and are H or D in each case; Among them, it is optional to 2 =NAr 2 , the carbazole group has two adjacent R groups that form a ring system with each other, thereby forming a structure of one of formulas (CARB-1) to (CARB-6): where Y 3 is C(R')2 and R' is phenyl, wherein the phenyl groups may be linked to each other to form a ring and the structure is linked to dibenzofuran or dibenzothiophene via a dotted bond; p, q, r are in each case identical or different and are 0, 1, 2 or 3; s is identical or different in each case and is 0, 1, 2, 3 or 4.

2. The compound according to claim 1, which is a compound of formula (3), wherein Z is N and the other symbols and indices have the meanings given in claim 1.

3. The compound according to claim 1 or 2, characterized in that Y 2 It's O.

4. The compound according to claim 1, which is a compound of formula (4), wherein Z is N and the other symbols and indices have the meanings given in claim 1.

5. The compound according to claim 1, which is a compound of formula (5), The symbols and signs have the meanings given in claim 1.

6. The compound according to claim 1, which is a compound of formula (1a), wherein Z is N and the other symbols and indices have the meanings given in claim 1.

7. The compound according to claim 1, which is a compound of formula (2a), Here, p, q, r, s are in each case identical or different and are 0 or 1, and the other symbols and signs have the definitions given in claim 1.

8. The compound according to claim 1, which is a compound of formula (3a), wherein Z is N and the other symbols and indices have the meanings given in claim 1.

9. The compound according to claim 1, which is a compound of formula (4a), wherein Z is N and the other symbols and indices have the meanings given in claim 1.

10. The compound according to claim 1, which is a compound of formula (5a), The symbols and signs have the meanings given in claim 1.

11. The compound according to claim 1, which is a compound of formula (6a), where the symbols have the meanings given in claim 1 and s is in each case identical or different and is 0 or 1.

12. The compound according to any one of claims 1 to 2 and 4 to 11, characterized in that Ar 1 and Ar 2 are identical or different in each case and are selected from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, naphthalene, indole, benzofuran, benzothiophene, carbazole, dibenzofuran, dibenzothiophene, indenocarbazole, indolocarbazole, phenanthrene, terphenylidene or a combination of two or three of these radicals, each of which may be substituted by one or more R radicals.

13. A method for preparing a compound according to any one of claims 1 to 12, the method comprising: 1 The functionalized dichlorotriazine is reacted with 1-dibenzofuranboronic acid or an ester thereof or 1-dibenzothiopheneboronic acid or an ester thereof in a Suzuki coupling.

14. A formulation comprising at least one compound according to any one of claims 1 to 12 and at least one further compound and / or solvent.

15. Use of a compound according to any one of claims 1 to 12 or a formulation according to claim 14 in an electronic device.

16. An electronic device comprising at least one compound according to any one of claims 1 to 12 or a formulation according to claim 14.

17. The electronic device according to claim 16, wherein the electronic device is an organic electroluminescent device, characterized in that The compound according to any one of claims 1 to 12 is used as matrix material for a phosphorescent emitter or a matrix material for an emitter exhibiting TADF (thermally activated delayed fluorescence) in an emitting layer and / or in an electron transport layer and / or in a hole blocking layer.

18. The electronic device according to claim 17, characterized in that The compound according to any one of claims 1 to 12 is used as a matrix material for a phosphorescent emitter in an emitting layer, wherein the compound is 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, borazolidines, boric esters, triazine derivatives, zinc complexes, siladiazacyclopentazone or siladiazacyclopentazone derivatives, phosphadiazacyclopentazone derivatives, bridged carbazole derivatives, terphenylidene derivatives, dibenzofuran derivatives, dibenzothiophene derivatives, wide bandgap materials and / or phosphorescent compounds having shorter-wavelength emission than the actual emitter.

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