Nitrogen-containing heterocyclic compounds for organic electroluminescent devices

Abstract

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

Description

[0001] The present invention relates to nitrogen-containing heterocyclic compounds for use in electronic devices, in particular for use in organic electroluminescent devices, and to electronic devices, in particular organic electroluminescent devices, comprising these materials.

[0002] Electronic devices containing organic compounds are well known and commercially available. These devices can, for example, each contain 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. Generally, there is a need for improvement in the performance of these devices, in particular the compounds used in the layers detailed above have a significant impact on the performance of the devices.

[0003] Furthermore, the luminescent materials used in organic electroluminescent devices are usually phosphorescent organometallic complexes. For quantum mechanical reasons, the use of organometallic compounds as phosphorescent emitters can achieve up to four times the energy efficiency and power efficiency. In electroluminescent devices, especially in electroluminescent devices that also exhibit triplet luminescence (phosphorescence), improvement is usually still needed. The properties of phosphorescent electroluminescent devices depend not only on the triplet emitters used. More particularly, other materials such as the host material used are also particularly important here. Therefore, the improvement of these materials can also cause a significant improvement in the performance of electroluminescent devices.

[0004] Similar statements also apply to organic electroluminescent devices based on phosphorescent emitters or emitters exhibiting TADF (thermally activated delayed fluorescence).

[0005] EP 3 070 144 A1 and WO 2017 / 178864 A1 disclose nitrogen-containing heterocyclic compounds that can be used in organic electroluminescent devices. The compounds according to the present invention are not disclosed.

[0006] Generally, when these materials are used, for example, as host materials and hole transport materials and / or electron transport materials, improvement is still needed, especially in terms of the efficiency and operating voltage of the device, and improvement is still needed in terms of the lifetime.

[0007] Therefore, an object of the present invention is to provide a compound and to provide a corresponding electronic device, the compound being suitable for use in organic electronic devices, in particular in organic electroluminescent devices, and the compound causing good device performance when used in such devices.

[0008] More particularly, an object solved by the present invention is to provide compounds that cause high lifetime, good efficiency, and low operating voltage. In particular, the properties of the host material also have a significant impact on the lifetime and efficiency of organic electroluminescent devices.

[0009] Another object of the present invention may be considered to provide compounds suitable for use in phosphorescent or fluorescent electroluminescent devices, especially as host materials. A particular object of the present invention is to provide host materials which are suitable for electroluminescent devices for blue, green, yellow and red phosphorescence, especially for electroluminescent devices for blue phosphorescence.

[0010] Furthermore, the compounds, especially when they are used as host materials, as hole transport materials or as electron transport materials in organic electroluminescent devices, should give rise to devices with excellent lifetime and efficiency.

[0011] Another object may be considered to provide very inexpensive and quality-stable electronic devices with excellent performance.

[0012] Furthermore, the electronic devices should be usable or adaptable for many purposes. More particularly, the performance of the electronic devices should be maintained over a wide temperature range.

[0013] It has surprisingly been found that this object is achieved by the specific compounds described later, which are very suitable for use in electroluminescent devices and cause organic electroluminescent devices to exhibit good performance, especially in terms of lifetime, color purity and efficiency, and operating voltage. Accordingly, the present invention provides these compounds and electronic devices, especially organic electroluminescent devices, containing these compounds.

[0014] The present invention provides a compound which contains at least one structure of formula (I), preferably a compound of formula (I),

[0015]

[0016] wherein the symbols are as follows:

[0017] A is the same or different in each case and is B(R), B(Ar), P(R)O, P(Ar)O, C(R) 2 , C(Ar) 2 , Si(R) 2 , Si(Ar) 2 , Ge(R) 2 , Ge(Ar) 2 , Ti(R) 2 , Ti(Ar) 2 , Zr(R) 2 , Zr(Ar) 2 , Hf(R) 2 , Hf(Ar) 2 , SO 2 or SO, preferably B(R), B(Ar), P(R)O, P(Ar)O, C(R) 2, C(Ar) 2 , Si(R) 2 , Si(Ar) 2 , Ge(R) 2 or Ge(Ar) 2 , more preferably C(R) 2 , C(Ar) 2 , Si(R) 2 , Si(Ar) 2 , Ge(R) 2 or Ge(Ar) 2 , most preferably Si(Ar) 2 or Si(R) 2 ;

[0018] Z is the same or different in each case and is N(R a ), N(Ar a ), O or S, preferably N(R a ) or N(Ar a ), most preferably N(Ar a );

[0019] X 1 is the same or different in each case and is N or CR b , preferably N, provided that no more than two of the X 1 , X 2 , X 3 groups in a ring are N, or the X 1 group and the X 2 group together form an ortho-bonded aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms and which may be substituted by one or more R b groups;

[0020] X 2 is the same or different in each case and is N or CR b , preferably CR b , provided that no more than two of the X 1 , X 2 , X 3 groups in any ring are N;

[0021] X 3 is the same or different in each case and is N or CR b , provided that no more than two of the X 1 , X 2 , X 3 groups in a ring are N, or the X 3 group and the X 2The groups together form an ortho-bonded aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms and may be substituted by one or more R b groups, where in any ring the X 2 group forms an aromatic or heteroaromatic ring system with no more than one X 1 or X 3 group;

[0022] R is the same or different in each case and is H, D, OH, F, Cl, Br, I, CN, NO 2 , N(Ar) 2 , N(R c ) 2 , C(=O)N(Ar) 2 , C(=O)N(R c ) 2 , C(Ar) 3 , C(R c ) 3 , Si(Ar) 3 , Si(R c ) 3 , Ge(R c ) 2 , Ge(Ar) 3 , B(Ar) 2 , B(R c ) 2 , C(=O)Ar, C(=O)R c , P(=O)(Ar) 2 , P(=O)(R c ) 2 , P(Ar) 2 , P(R c ) 2 , S(=O)Ar, S(=O)R c , S(=O) 2 Ar, S(=O) 2 R c , OSO 2 Ar, OSO 2 R c , a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 carbon atoms or an alkenyl or alkynyl group having 2 to 40 carbon atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 carbon atoms, where the alkyl, alkoxy, thioalkoxy, alkenyl or alkynyl group may in each case be substituted by one or more R c groups, where one or more non-adjacent CH 2 groups may be replaced by R c C=CR c, C≡C, Si(R c ) 2 , Ge(R c ) 2 , C=O, C=S, C=Se, C=NR c , -C(=O)O-, -C(=O)NR c -, NR c , P(=O)(R c ), -O-, -S-, SO or SO 2 is replaced, or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms and in each case being optionally substituted by one or more R c groups, or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms and being optionally substituted by one or more R c groups, or an arylthio or heteroarylthio group having 5 to 60 aromatic ring atoms and being optionally substituted by one or more R c groups, or a diarylamino, arylheteroarylamino, diheteroarylamino group having 5 to 60 aromatic ring atoms and in each case being optionally substituted by one or more R c groups, or an aralkyl or heteroaralkyl group having 5 to 60 aromatic ring atoms and 1 to 10 carbon atoms in the alkyl group and being optionally substituted by one or more R c groups; simultaneously, one R group may form a ring system together with other groups, preferably with R b ;

[0023] Ar is the same or different in each case and is an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms and being optionally substituted by one or more R c groups; simultaneously, two Ar groups bonded to the same carbon atom, silicon atom, germanium atom, titanium atom, zirconium atom, hafnium atom may also be bridged to each other by a single bond or a bridging group selected from: B(R c ), C(R c ) 2 , Si(R c ) 2 , Ge(R c ) 2 , C=O, C=NR c , C=C(R c ) 2 , O, S, S=O, SO 2 , N(R c ), P(R c ) and P(=O)R c ;

[0024] Ar aSame or different in each case and being an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms and being optionally substituted by one or more R a groups;

[0025] R a 、R b 、R c Same or different in each case and being H, D, OH, F, Cl, Br, I, CN, NO 2 , N(Ar') 2 , N(R 1 ) 2 , C(=O)N(Ar') 2 , C(=O)N(R 1 ) 2 , C(Ar') 3 , C(R 1 ) 3 , Si(Ar') 3 , Si(R 1 ) 3 、Ge(Ar') 3 、Ge(R 1 ) 3 , B(Ar') 2 , B(R 1 ) 2 , C(=O)Ar', C(=O)R 1 , P(=O)(Ar') 2 , P(=O)(R 1 ) 2 , P(Ar') 2 , P(R 1 ) 2 , S(=O)Ar', S(=O)R 1 , S(=O) 2 Ar', S(=O) 2 R 1 , OSO 2 Ar', OSO 2 R 1 , a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 carbon atoms or an alkenyl or alkynyl group having 2 to 40 carbon atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl or alkynyl group is in each case optionally substituted by one or more R 1 groups, wherein one or more non-adjacent CH 2 groups may be replaced by R 1 C=CR 1 、C≡C、Si(R 1 )2 , Ge(R 1 ), 2 , C═O, C═S, C═Se, C═NR 1 , -C(═O)O-, -C(═O)NR 1 -, NR 1 , P(═O)(R 1 ), -O-, -S-, SO or SO 2 is replaced, or is an aromatic or heteroaromatic ring system having from 5 to 60 aromatic ring atoms and in each case being optionally substituted by one or more R 1 groups, or an aryloxy or heteroaryloxy group having from 5 to 60 aromatic ring atoms and being optionally substituted by one or more R 1 groups; simultaneously, two R a , R b , R c groups may also form a ring system with each other or with other groups, preferably with R;

[0026] Ar' is the same or different in each case and is an aromatic or heteroaromatic ring system having from 5 to 60 aromatic ring atoms and being optionally substituted by one or more R 1 groups, where two Ar' groups bonded to the same carbon atom, silicon atom, germanium atom, nitrogen atom, phosphorus atom or boron atom may also be bridged to each other by a single bond or a bridging group selected from: B(R 1 ), C(R 1 ) 2 , Si(R 1 ) 2 , C═O, C═NR 1 , C═C(R 1 ) 2 , O, S, S═O, SO 2 , N(R 1 ), P(R 1 ) and P(═O)R 1 ;

[0027] R 1 is the same or different in each case and is H, D, F, Cl, Br, I, CN, NO 2 , N(Ar”), 2 , N(R 2 ) 2 , C(═O)Ar”, C(═O)R 2 , P(═O)(Ar”), 2 , P(Ar”), 2 , B(Ar”), 2 , B(R 2 ), 2 , C(Ar”)3 , C(R 2 ), 3 , Si(Ar”) 3 , Si(R 2 ), 3 , a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 carbon atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 40 carbon atoms or an alkenyl group having 2 to 40 carbon atoms, each of said groups being optionally substituted by one or more R 2 groups, wherein one or more non-adjacent CH 2 groups may be replaced by -R 2 C═CR 2 -, -C≡C-, Si(R 2 ), 2 , C═O, C═S, C═Se, C═NR 2 , -C(═O)O-, -C(═O)NR 2 (-), NR 2 , P(═O)(R 2 ), -O-, -S-, SO or SO 2 and wherein one or more hydrogen atoms may be replaced by D, F, Cl, Br, I, CN or NO 2 , or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms and being optionally substituted in each case by one or more R 2 groups, or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms and being optionally substituted by one or more R 2 groups, or an aralkyl or heteroaralkyl group having 5 to 60 aromatic ring atoms and being optionally substituted by one or more R 2 groups, or a combination of these systems; simultaneously, two or more preferably adjacent R 1 groups may together form a ring system; simultaneously, one or more R 1 groups may form a ring system with other parts of the compound;

[0028] Ar” is the same or different in each case and is an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms and being optionally substituted by one or more R 2 groups, wherein two Ar” groups bonded to the same carbon atom, silicon atom, nitrogen atom, phosphorus atom or boron atom may also be bridged to each other by a single bond or a bridging group selected from: B(R 2 ), C(R 2 ), 2 , Si(R 2 ), 2 , C═O, C═NR 2 , C═C(R2 ) 2 、 O, S, S=O, SO 2 、 N(R 2 )、 P(R 2 ) and P(=O)R 2 ;

[0029] R 2 is the same or different in each case and is selected from H, D, F, CN, an aliphatic hydrocarbon radical having 1 to 20 carbon atoms or an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms and in which one or more hydrogen atoms may be replaced by D, F, Cl, Br, I or CN, and said aromatic or heteroaromatic ring system may be substituted by one or more alkyl groups each having 1 to 4 carbon atoms, where two or more preferably adjacent substituents R 2 together may form a ring system.

[0030] Preferably, in one possible case, exactly one X 1 、 X 3 group is N, more preferably the X 1 group is N.

[0031] 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 3 to 40 carbon atoms and at least one heteroatom, provided that the sum of the carbon atoms and the heteroatoms is at least 5. The heteroatom is preferably selected from N, O and / or S. Here, an aryl group or a heteroaryl group is understood to mean a simple aromatic ring, i.e. benzene; or a simple heteroaromatic ring such as pyridine, pyrimidine, thiophene, etc.; or a fused (annelated) aryl or heteroaryl group such as naphthalene, anthracene, phenanthrene, quinoline, isoquinoline, etc. In contrast, an aromatic compound connected to each other by a single bond such as biphenyl is not called an aryl or heteroaryl group, but is called an aromatic ring system.

[0032] An electron-deficient heteroaryl group in the context of the present invention is a heteroaryl group having at least one heteroaromatic six-membered ring having at least one nitrogen atom. Other aromatic or heteroaromatic five-membered or six-membered rings may be fused to this six-membered ring. Examples of electron-deficient heteroaryl groups are pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, quinazoline or quinoxaline.

[0033] In the context of the present invention, an aromatic ring system contains from 6 to 60 carbon atoms in the ring system. In the context of the present invention, a heteroaromatic ring system contains from 3 to 60 carbon atoms and at least one heteroatom in the ring system, provided that the sum of the carbon atoms and heteroatoms is at least 5. The heteroatom is preferably selected from N, O and / or S. In the context of the present invention, an aromatic or heteroaromatic ring system is understood to mean a system which does not have to contain only aryl or heteroaryl groups, but in which two or more aryl or heteroaryl groups can also be linked via non-aromatic units, such as carbon, nitrogen or oxygen atoms. For example, in the context of the present invention, systems such as fluorene, 9,9'-spirobifluorene, 9,9-diarylfluorene, triarylamine, diaryl ether, stilbene and the like should also be regarded as aromatic ring systems, and so are systems in which two or more aryl groups are linked, for example, via short alkyl groups. Preferably, the aromatic ring system is selected from fluorene, 9,9'-spirobifluorene, 9,9-diarylamine or groups in which two or more aryl and / or heteroaryl groups are linked to one another via single bonds.

[0034] In the context of the present invention, it may contain from 1 to 20 carbon atoms and in which individual hydrogen atoms or CH 2The aliphatic hydrocarbon group, alkyl group, alkenyl group or alkynyl group which may also be substituted by the above-mentioned groups is preferably understood to mean 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 group. The alkoxy group having 1 to 40 carbon atoms is preferably understood to mean methoxy, trifluoromethoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, isobutoxy, sec-butoxy, tert-butoxy, n-pentyloxy, sec-pentyloxy, 2-methylbutoxy, n-hexyloxy, cyclohexyloxy, n-heptyloxy, cycloheptyloxy, n-octyloxy, cyclooctyloxy, 2-ethylhexyloxy, pentafluoroethoxy and 2,2,2-trifluoroethoxy. The thioalkyl group having 1 to 40 carbon atoms should be understood to mean especially 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, the alkyl, alkoxy or thioalkyl group according to the present invention may be straight-chain, branched-chain or cyclic, and one or more non-adjacent CH 2 groups may be replaced by the above-mentioned groups; in addition, one or more hydrogen atoms may also be replaced by D, F, Cl, Br, I, CN or NO 2 and are preferably replaced by F, Cl or CN, more preferably replaced by F or CN, and particularly preferably replaced by CN.

[0035] An aromatic or heteroaromatic ring system having 5 to 60 or 5 to 40 aromatic ring atoms and which in each case may also be substituted by the abovementioned groups and which may be linked to an aromatic or heteroaromatic system via any desired position shall be understood in particular to mean a group derived from the following substances: benzene, naphthalene, anthracene, benzanthracene, phenanthrene, pyrene, chrysene, perylene, fluoranthene, tetracene, pentacene, benzopyrene, biphenyl, bibenzylidene, terphenyl, terbenzylidene, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, cis- or trans-indeno[1,2-b]fluorene, cis- or trans-indenocarbazole, cis- or trans-indolocarbazole, triphenylene, isotriphenylene, spirotriphenylene, spiroisotriphenylene, 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, phen azine, pyrazole, indazole, imidazole, benzimidazole, naphthimidazole, phenanthrimidazole, pyridinimidazole, pyrazinimidazole, quinoxalinimidazole, azole, benzo azole, naphtho azole, anthra azole, phenanthro azole, iso azole, 1,2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, hexazatriphenylene, 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 azine, phenothiazine, fluoranthene ring, naphthyridine, azacarbazole, benzocarbazole, phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3- diazole, 1,2,4- diazole, 1,2,5- diazole, 1,3,4- diazole, 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 a group derived from a combination of these systems.

[0036] In the context of the present specification, the phrase two or more groups together may form a ring shall be understood in particular to mean that the two groups are linked to each other by a chemical bond under the condition that two hydrogen atoms are formally eliminated. This is illustrated by the following scheme:

[0037]

[0038] However, in addition, the above wording should also be understood to mean that if one of the two groups is hydrogen, the second group combines with the position to which the hydrogen atom is bonded to form a ring. This will be illustrated by the following scheme:

[0039]

[0040] In a preferred configuration, the compounds of the present invention may preferably comprise at least one structure of formula (I-1) to (I-11), more preferably compounds selected from formula (I-1) to (I-11),

[0041]

[0042]

[0043]

[0044] wherein the symbols Z, A and R b have the definitions given above, in particular the definitions given for formula (I), and X is N or C(R b ), preferably C(R b ). Preferably, no more than 3, more preferably no more than two X groups are N.

[0045] Here, structures / compounds of formula (I-1) to (I-4) are preferred, structures / compounds of formula (I-1) and / or (I-2) are particularly preferred, and the structure / compound of formula (I-1) is very particularly preferred.

[0046] The Z group is preferably N(Ar a ), wherein the preferred configuration of the Ar a group is also presented below in connection with the Ar group which can be part of the Z group.

[0047] The A group is preferably B(Ar), P(Ar)O, C(Ar) 2 , Si(Ar) 2 or Ge(Ar) 2 , wherein the preferred configuration of the Ar group is also presented below in connection with the Ar a group which can be part of the A group.

[0048] Preferably, the Ar, Ar a and / or R groups are aromatic or heteroaromatic ring systems having 5 to 18 aromatic ring atoms, preferably 6 to 13 aromatic ring atoms and which can be substituted by one or more R a or R c groups.

[0049] In addition, it is feasible that Ar and / or Ar a groups are the same or different in each case and are selected from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthalene, indole, benzofuran, benzothiophene, carbazole, dibenzofuran, dibenzothiophene, indolocarbazole, indolo[2,3-a]carbazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, isoquinoline, quinazoline, quinoxaline, anthracene, phenanthrene or terphenylene, and each of said groups may be substituted by one or more R c or R a groups, preferably phenyl, biphenyl, fluorene, dibenzofuran, terphenylene, carbazole, indolocarbazole.

[0050] Ar a groups and / or Ar groups may preferably be phenyl groups substituted by at least one R a or R c group, wherein the substituent is in the ortho, meta or para position to the nitrogen atom in the N(Ar a ) group or the boron atom, phosphorus atom, carbon atom, silicon atom or germanium atom of the A group. For example, if the R a or R c group is a phenyl group, an ortho-biphenyl, meta-biphenyl or para-biphenyl group may be formed.

[0051] If the Ar a group and / or Ar group is a triazine group, it is preferably feasible that the triazine group has two R a or R c groups that are not H or D, wherein the two R a or R c groups are preferably aromatic or heteroaromatic ring systems having 5 to 60, preferably 6 to 30 aromatic ring atoms and may be substituted by one or more R 1 groups in each case.

[0052] In addition, the Ar a group and / or Ar group may preferably be a phenyl group substituted by at least one R a or R c group, wherein the substituent and the phenyl group represented by the Ar a group and / or Ar group together form a fluorene group that can be bonded via the 1-position, 2-position, 3-position or 4-position, a spirobifluorene group that can be bonded via the 1-position, 2-position, 3-position or 4-position, an indole group, a benzofuran group, a benzothiophene group, a carbazole group that can be bonded via the 1-position, 2-position, 3-position or 4-position, a dibenzofuran group that can be bonded via the 1-position, 2-position, 3-position or 4-position, a dibenzothiophene group that can be bonded via the 1-position, 2-position, 3-position or 4-position, an indolocarbazole group or an indolo[2,3-a]carbazole group.

[0053] In another preferred embodiment, it is feasible that the A group is C(R) 2 , Si(R) 2 or Ge(R) 2 , where the preferred R groups are selected from straight-chain alkyl groups having 1 to 40 carbon atoms or alkenyl or alkynyl groups having 2 to 40 carbon atoms or branched or cyclic alkyl groups having 3 to 20 carbon atoms, where the group in each case can be substituted by one or more R c groups.

[0054] In another configuration, it is feasible that the structure / compound according to the invention comprises at least one electron-transporting group and / or electron-withdrawing group. Electron-transporting groups are well known in the art and promote the ability of the compound to transport and / or conduct electrons. Examples of electron-transporting groups are pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinazoline, quinoxaline, quinoline, isoquinoline, imidazole and / or benzimidazole groups, with triazine groups being particularly preferred. Electron-withdrawing groups especially include SO 2 , B(R), B(Ar), P(RO), P(ArO), which groups can be present, for example, as the A group. In addition, these electron-withdrawing groups can also be present as substituents R a , R b , R c in the structures / compounds of formula (I) and / or formulae (I-1) to (I-11), for example, as the substituent B(Ar') 2 , B(R 1 ) 2 , P(=O)(Ar') 2 , P(=O)(R 1 ) 2 , S(=O) 2 Ar', S(=O) 2 R 1 in the structures / compounds of formula (I) and / or formulae (I-1) to (I-11). In addition, electron-withdrawing groups also include, for example, the C=O group or the CN group, which groups can be present as substituents in the structure, for example, as the substituents C(=O)Ar, C(=O)Ar', C(=O)R c , C(=O)R a or C(=O)R 1 in the structure.

[0055] In another configuration, it is feasible that the structure / compound according to the invention comprises at least one hole-transporting group. Hole-transporting groups are likewise known in the art and preferably include triarylamine or carbazole groups.

[0056] The compounds of the present invention are particularly suitable as host materials for emitters, preferably as host materials for singlet, triplet, and TADF emitters; electron transport materials; electron injection materials; hole conduction materials; hole injection materials; electron blocking materials; hole blocking materials in electronic devices. The specific properties of the compounds depend here on the type and number of the corresponding functional groups. Compounds containing one, two or more electron transport groups and / or electron-withdrawing groups but no hole transport groups are particularly suitable as host materials, electron transport materials, electron injection materials and / or hole blocking materials. Compounds containing one, two or more hole transport groups but no electron transport groups and / or electron-withdrawing groups are particularly suitable as host materials, hole conduction materials, hole injection materials and / or electron blocking materials. Compounds containing one, two or more hole transport groups as well as one, two or more electron transport groups and / or electron-withdrawing groups are particularly suitable as host materials.

[0057] It is also possible that at least one, preferably all, of the R, R a groups are not H, preferably not H, D, OH, NO 2 , F, Cl, Br, I.

[0058] In another preferred embodiment, it is possible that the compounds of the present invention contain the structures of formulae (II-1) to (II-8), wherein the compounds of the present invention are more preferably selected from the compounds of formulae (II-1) to (II-8),

[0059]

[0060]

[0061] wherein the symbols A and R b have the definitions given above, in particular the definitions given for formula (I), and the other symbols are as follows:

[0062] X a is in each case the same or different and is N, CR a , or if a group is bonded to the structure then X a is C, X a is preferably CR a or C, provided that no more than three of the X a groups in any ring are N, wherein R a has the definition given above, in particular the definition given for formula (I);

[0063] Y is in each case the same or different and is B(R a ), C(R a ), 2 , Si(Ra ) 2 , Ge(R a ) 2 、C=O、C=NR a , C=C(R a ) 2 ,O,S,S=O,SO 2 、N(R a )、P(R a ) or P(=O)R a , preferably N(R a )、O、S、B(R a )、C(R a ) 2 、Si(R a ) 2 or Ge(R a ) 2 , more preferably N(R a ), O or S, where R a has the meaning given in claim 1, or if there is a group bonded to the structure, Y is C(R a )-、Si(R a )-、Ge(R a )-;

[0064] n is 0, 1, 2 or 3, preferably 0, 1 or 2; and

[0065] m is 0, 1, 2, 3 or 4, preferably 0, 1 or 2.

[0066] Preference is given here to structures / compounds of the formulae (II-1), (II-2) and (II-3), particular preference to structures / compounds of the formulae (II-1) and (II-2), very particular preference to structures / compounds of the formula (II-1).

[0067] In formulae (II-1) to (II-8), it is possible that if there is a group bonded to a specific structure, then X a is C. This group is in particular a ring structure having a Y group and is shown in formula (II-2) or (II-4). The ring structure can be substituted by X a group or bonded via Y, where in the latter case Y is C(R a )-、Si(R a )-、Ge(R a )-.

[0068] In one embodiment, it is possible that in the structures / compounds of formula (II-1) to (II-8), no more than three, preferably two, X a The group is N, preferably all X a CRa ; preferably at least one, more preferably at least two Xs for each ring a The groups are selected from C-H and C-D.

[0069] In a further possible case, at least one, preferably at least two, more preferably three Xs for each ring a The groups are N, where these groups are preferably not adjacent. These structures / compounds preferably contain electron-transporting groups and are thus particularly suitable as electron-transporting materials and / or matrix materials.

[0070] In another preferred embodiment, it is possible that the compounds of the present invention contain the structures of formulas (III-1) to (III-12), where the compounds of the present invention are more preferably selected from the compounds of formulas (III-1) to (III-12),

[0071]

[0072]

[0073] where the symbols A, R a and R b have the definitions given above, in particular the definitions given for formula (I), and the other symbols are as follows:

[0074] Y is the same or different in each case and is B(R a ), C(R a ), 2 Si(R a ), 2 Ge(R a ), 2 C=O, C=NR a C=C(R a ), 2 O, S, S=O, SO 2 N(R a ), P(R a ) or P(=O)R a , preferably N(R a ), O, S, B(R a ), C(R a ), 2 Si(R a ), 2 or Ge(R a ), 2 , more preferably N(R a ), O or S;

[0075] j is 0, 1 or 2;

[0076] n is 0, 1, 2 or 3, preferably 0, 1 or 2;

[0077] m is 0, 1, 2, 3 or 4, preferably 0, 1 or 2;

[0078] l is 0, 1, 2, 3, 4 or 5, preferably 0, 1 or 2.

[0079] Here, the structures / compounds of formulas (III-1) to (III-8) are preferred, particularly preferred are the structures / compounds of formulas (III-1), (III-2), (III-5) and (III-6), and very particularly preferred are the structures / compounds of formulas (III-1) and (III-2).

[0080] The sum of the labels j, m, n and l in the structures / compounds of formulas (III-1) to (III-12) is preferably not greater than 6, particularly preferably not greater than 4, and more preferably not greater than 2.

[0081] In another preferred embodiment, it is feasible that the compounds of the present invention comprise the structures of formulas (IV-1) to (IV-48), wherein the compounds of the present invention are more preferably selected from the compounds of formulas (IV-1) to (IV-48),

[0082]

[0083]

[0084]

[0085]

[0086]

[0087]

[0088]

[0089]

[0090] wherein the symbol R a 、R b and R c have the definitions given above, in particular the definitions given for formula (I), and the other symbols are as follows:

[0091] M is the same or different in each case and is C, Si, Ge, Ti, Zr or Hf, preferably C, Si or Ge, more preferably Si;

[0092] Y is the same or different in each case and is B(R a )、C(R a ) 2, Si(R a ) 2 , Ge(R a ) 2 , C=O, C=NR a , C=C(R a ) 2 , O, S, S=O, SO 2 , N(R a ), P(R a ) or P(=O)R a , preferably N(R a ), O, S, B(R a ), C(R a ) 2 , Si(R a ) 2 or Ge(R a ) 2 , more preferably N(R a ), O or S;

[0093] j is 0, 1 or 2;

[0094] n is 0, 1, 2 or 3, preferably 0, 1 or 2;

[0095] m is 0, 1, 2, 3 or 4, preferably 0, 1 or 2;

[0096] l is 0, 1, 2, 3, 4 or 5, preferably 0, 1 or 2.

[0097] Structures / compounds of formulae (IV-1) to (IV-8), (IV-13) to (IV-20), (IV-25), (IV-26), (IV-29), (IV-30) and (IV-38) are preferably used herein, structures / compounds of formulae (IV-1), (IV-2), (IV-5), (IV-6), (IV-13), (IV-14), (IV-25) and (IV-26) are particularly preferably used, and structures / compounds of formulae (IV-1), (IV-2), (IV-13) and (IV-14) are very particularly preferably used.

[0098] The sum of the labels j, m, n and l in the structures / compounds of formulae (IV-1) to (IV-48) is preferably not greater than 6, particularly preferably not greater than 4, and more preferably not greater than 2.

[0099] When it is particularly optionally selected from R, R a , R b , R c , R 1 and / or R 2When two groups form a ring system with each other, the ring system can be a monocyclic or polycyclic aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system. In this case, the groups that together form the ring system can be adjacent, which means that these groups are bonded to the same carbon atom or to carbon atoms that are directly bonded to each other, or they can be further apart from each other. In addition, the ring systems having substituents R, R a 、R b 、R c 、R 1 and / or R 2 can also be connected to each other via bonds, so that this can achieve ring closure.

[0100] In a preferred embodiment of the present invention, it is feasible that at least two preferably adjacent R, R a 、R b 、R c groups together with the other groups to which the two R, R a 、R b 、R c groups are bonded form a fused ring. In a preferred configuration, it is feasible that a ring structure as described in the following documents is formed: Document WO 2022 / 079068 A1 with application number PCT / EP2021 / 078240 filed with the European Patent Office on October 13, 2021; for the purpose of disclosure, the fused ring structures shown in these documents and the descriptions of the ring elements of formulas (RA-1) to (RA-12), (RA-1a) to (RA-4f) and / or (RB) on pages 37 to 40 of document WO 2022 / 079068 A1 are incorporated into the present application by reference thereto. The above-described ring structure shown in detail in document WO2022 / 079068A1 and preferably containing the ring elements of formulas (RA-1) to (RA-12) and (RA-1a) to (RA-4f) particularly causes the structures / compounds of the present invention to have a surprisingly low refractive index.

[0101] It is also feasible that the substituents R a 、R b 、R c 、R 1 and R 2 according to the above formula do not form a fused aromatic or heteroaromatic ring system with the ring atoms of the ring system to which the substituents R a 、R b 、R c 、R 1 and R 2 are bonded, and more preferably do not form a fused aromatic or heteroaromatic ring system with the substituents R a 、R b 、R c 、R 1 and R2 The ring atoms of the fused ring system form a ring system. This includes substituents R a 、R b 、R c and R 1 for which the possible substituent R 2 forms a fused aromatic or heteroaromatic ring system.

[0102] It is also possible that at least one of R a 、R b 、R c groups is the same or different in each case and is selected from H, D, a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 carbon atoms or an aromatic or heteroaromatic ring system selected from the groups of the formulae Ar-1 to Ar-76, or R a 、R b 、R c groups is the same or different in each case and is selected from H, D or an aromatic or heteroaromatic ring system selected from the groups of the formulae Ar-1 to Ar-76, and / or the Ar' groups are the same or different in each case and are selected from the groups of the formulae Ar-1 to Ar-76,

[0103]

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110] wherein R 1 has the definition given above, the dashed bond represents a bond to the corresponding group, and furthermore:

[0111] Ar 1 is the same or different in each case and is a divalent aromatic or heteroaromatic ring system having 6 to 18 aromatic ring atoms and which may in each case be substituted by one or more R 1 groups;

[0112] A is the same or different in each case and is C(R 1 ) 2 、NR 1 、O or S;

[0113] p is 0 or 1, where p = 0 means that the Ar 1 group is absent and the corresponding aromatic or heteroaromatic group is directly bonded to the corresponding group;

[0114] q is 0 or 1, where q = 0 means that no A group is bonded at this position, while the R 1 group is bonded to the corresponding carbon atom.

[0115] Here, the structures of formulae (Ar-1), (Ar-2), (Ar-3), (Ar-12), (Ar-13), (Ar-14), (Ar-15), (Ar-16), (Ar-40), (Ar-41), (Ar-42), (Ar-43), (Ar-44), (Ar-45), (Ar-46), (Ar-69), (Ar-70), (Ar-76) are preferred, and the structures of formulae (Ar-1), (Ar-2), (Ar-3), (Ar-12), (Ar-13), (Ar-14), (Ar-15), (Ar-16) are particularly preferred.

[0116] When there are two or more A groups for the above groups in the structures of formulae (Ar-1) to (Ar-76), all combinations from the definition of A are included for these possible options. In this case, preferred embodiments are those in which one A group is NR 1 and the other A group is C(R 1 ) 2 or those cases in which both A groups are NR 1 or both A groups are O.

[0117] When A is NR 1 , the substituent R bonded to the nitrogen atom 1 is preferably an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms and which may also be substituted by one or more R 2 groups. In a particularly preferred embodiment, the R 1 substituents are the same or different in each case and are an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, especially 6 to 18 aromatic ring atoms, which does not have any fused aryl groups and any fused heteroaryl groups in which two or more aromatic or heteroaromatic 6-membered ring groups are directly fused to each other, and the aromatic or heteroaromatic ring system may also be substituted by one or more R 2 groups in each case. Phenyl, biphenyl, terphenyl and quaterphenyl are preferred. Also preferred are triazines, pyrimidines and quinazolines as listed above for Ar-47 to Ar-50, Ar-57 and Ar-58, where these structures may be substituted by one or more R 2 groups rather than by R1 Substituted.

[0118] When A is C(R 1 ) 2 the substituents R bonded to this carbon atom 1 are preferably in each case the same or different and are straight-chain alkyl groups having 1 to 10 carbon atoms or branched or cyclic alkyl groups having 3 to 10 carbon atoms or aromatic or heteroaromatic ring systems having 5 to 24 aromatic ring atoms, which may also be substituted by one or more R 2 groups. Most preferably, R 1 is a methyl group or a phenyl group. In this case, the R 1 groups may also together form a ring system, which gives rise to a spiro ring system.

[0119] Next, the preferred R a , R b and R c groups are described.

[0120] In a preferred embodiment of the invention, R a , R b and R c are in each case the same or different and are selected from H, D, F, CN, NO 2 , Si(R 1 ) 3 , B(OR 1 ) 2 , straight-chain alkyl groups having 1 to 20 carbon atoms or branched or cyclic alkyl groups having 3 to 20 carbon atoms, where the alkyl groups may in each case be substituted by one or more R 1 groups, or aromatic or heteroaromatic ring systems having 5 to 60 aromatic ring atoms, preferably 5 to 40 aromatic ring atoms and which may in each case be substituted by one or more R 1 groups.

[0121] In another preferred embodiment of the invention, the groups R a , R b and R c are in each case the same or different and are selected from H, D, F, straight-chain alkyl groups having 1 to 20 carbon atoms or branched or cyclic alkyl groups having 3 to 20 carbon atoms, where the alkyl groups may in each case be substituted by one or more R 1 groups, or aromatic or heteroaromatic ring systems having 5 to 60 aromatic ring atoms, preferably 5 to 40 aromatic ring atoms and which may in each case be substituted by one or more R 1 groups.

[0122] It is also possible that at least one R a 、R b and R c groups, preferably one substituent R a 、R b and R c , which are the same or different in each case and are selected from H, D, an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms and which may be substituted by one or more R 1 groups, or an N(Ar') 2 group; more preferably, at least one substituent R a 、R b and R c are the same or different in each case and are selected from an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms and which may be substituted by one or more R 1 groups. In another preferred embodiment of the invention, the substituents R a 、R b and R c form a fused ring, or the R a 、R b and R c groups are the same or different in each case and are selected from H, D, an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms and which may be substituted by one or more R 1 groups, or an N(Ar') 2 group. More preferably, the R a 、R b and R c groups, preferably the substituents R a 、R b and R c , are the same or different in each case and are selected from H, or an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, preferably having 6 to 18 aromatic ring atoms, more preferably having 6 to 13 aromatic ring atoms, each of which may be substituted by one or more R 1 groups.

[0123] It is also possible that at least one R a 、R b and R c group is an aromatic or heteroaromatic ring system having 5 to 13 aromatic ring atoms and which may be substituted by one or more R 1 groups.

[0124] Preferably it is possible that at least one group, preferably one substituent R a 、R b and R c, selected from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthalene, indole, benzofuran, benzothiophene, carbazole, dibenzofuran, dibenzothiophene, indolocarbazole, indolocarbazole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, isoquinoline, quinazoline, quinoxaline, phenanthrene or terphenylidyne, each of said groups being optionally substituted by one or more R 1 groups. The expression "substituent" herein more particularly refers to R a , R b and R c not being H, preferably not being H and not being D. Further, if there are two or more substituents selected from the mentioned aromatic or heteroaromatic groups, the substituents R a , R b and R c may be the same or different.

[0125] Preferably, the aromatic or heteroaromatic ring systems represented by the substituents R, R a , R b and R c or Ar, Ar a or Ar' are selected from phenyl; biphenyl, especially o-biphenyl, m-biphenyl or p-biphenyl; terphenyl, especially o-terphenyl, m-terphenyl or p-terphenyl or branched terphenyl; quaterphenyl, especially o-quaterphenyl, m-quaterphenyl or p-quaterphenyl or branched quaterphenyl; fluorene which may be linked via the 1-position, 2-position, 3-position or 4-position; spirobifluorene which may be linked via the 1-position, 2-position, 3-position or 4-position; naphthalene, especially 1-bonded or 2-bonded naphthalene; indole; benzofuran; benzothiophene; carbazole which may be linked via the 1-position, 2-position, 3-position or 4-position; dibenzofuran which may be linked via the 1-position, 2-position, 3-position or 4-position; dibenzothiophene which may be linked via the 1-position, 2-position, 3-position or 4-position; indolocarbazole; indolocarbazole; pyridine; pyrimidine; pyrazine; pyridazine; triazine; quinoline; isoquinoline; quinazoline; quinoxaline; phenanthrene or terphenylidyne, each of which may be substituted by one or more R a , R c , R 1 or R 2 groups. Particularly preferably, the aromatic or heteroaromatic ring systems represented by the substituents R, R a , R b and R c or Ar, Ar aThe aromatic or heteroaromatic ring system represented by Ar' is the structure (Ar-1) to (Ar-76) detailed above, preferably the structures of formula (Ar-1), (Ar-2), (Ar-3), (Ar-12), (Ar-13), (Ar-14), (Ar-15), (Ar-16), (Ar-69), (Ar-70), (Ar-76), and particularly preferably the structures of formula (Ar-1), (Ar-2), (Ar-3), (Ar-12), (Ar-13), (Ar-14), (Ar-15), (Ar-16). Regarding the structures (Ar-1) to (Ar-76), it should be noted that these structures are substituted with the feasible substituents R 1 as shown. In the case of the ring system Ar a , these feasible substituents R 1 should be replaced by R a , and in the case of Ar, these feasible substituents R 1 should be replaced by R c .

[0126] Other suitable R a , R b , R c groups are groups of the formula -Ar 4 -N(Ar 2 )(Ar 3 ), where Ar 2 , Ar 3 and Ar 4 are the same or different in each case and are aromatic or heteroaromatic ring systems having 5 to 24 aromatic ring atoms and in each case may be substituted by one or more R 1 groups. Here, the total number of aromatic ring atoms in Ar 2 , Ar 3 and Ar 4 is not more than 60, preferably not more than 40.

[0127] Here, Ar 4 and Ar 2 may also be bonded to each other by a single bond or a group selected from C(R 1 ) 2 , NR 1 , O or S, and / or Ar 2 and Ar 3 may also be bonded to each other by a single bond or a group selected from C(R 1 ) 2 , NR 1 , O or S. Preferably, Ar 4 and Ar 2 are connected to each other at the respective ortho positions bonded to the nitrogen atom and Ar 2 and Ar3 are connected to each other at each ortho position bonded to a nitrogen atom. In another embodiment of the present invention, Ar 2 , Ar 3 and Ar 4 groups are not bonded to each other.

[0128] Preferably, Ar 4 is an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, preferably 6 to 12 aromatic ring atoms, and in each case may be substituted by one or more R 1 groups. More preferably, Ar 4 is selected from o-phenylene, m-phenylene or p-phenylene or o-biphenylylene, m-biphenylylene or p-biphenylylene, each of which may be substituted by one or more R 1 groups, but is preferably unsubstituted. Most preferably, Ar 4 is an unsubstituted phenylene group.

[0129] Preferably, Ar 2 and Ar 3 are the same or different in each case and are an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms and in each case may be substituted by one or more R 1 groups. Particularly preferably, Ar 2 and Ar 3 groups are the same or different in each case and are selected from: benzene; o-biphenylylene, m-biphenylylene or p-biphenylylene; o-terphenyl, m-terphenyl or p-terphenyl or branched terphenyl; o-quaterphenyl, m-quaterphenyl or p-quaterphenyl or branched quaterphenyl; 1-fluorenyl, 2-fluorenyl, 3-fluorenyl or 4-fluorenyl; 1-spirobifluorenyl, 2-spirobifluorenyl, 3-spirobifluorenyl or 4-spirobifluorenyl; 1-naphthyl or 2-naphthyl; indole; benzofuran; benzothiophene; 1-carbazolyl, 2-carbazolyl, 3-carbazolyl or 4-carbazolyl; 1-dibenzofuranyl, 2-dibenzofuranyl, 3-dibenzofuranyl or 4-dibenzofuranyl; 1-dibenzothiophenyl, 2-dibenzothiophenyl, 3-dibenzothiophenyl or 4-dibenzothiophenyl; indeno-carbazole; indolo-carbazole; 2-pyridine, 3-pyridine or 4-pyridine; 2-pyrimidine, 4-pyrimidine or 5-pyrimidine; pyrazine; pyridazine; triazine; phenanthrene or terphenylidene, each of which may be substituted by one or more R 1 groups. Most preferably, Ar 2 and Ar 3Identical or different in each case and selected from: benzene; biphenyl, especially o-biphenyl, m-biphenyl or p-biphenyl; terphenyl, especially o-terphenyl, m-terphenyl or p-terphenyl or branched terphenyl; quaterphenyl, especially o-quaterphenyl, m-quaterphenyl or p-quaterphenyl or branched quaterphenyl; fluorene, especially 1-fluorene, 2-fluorene, 3-fluorene or 4-fluorene; or spirobifluorene, especially 1-spirobifluorene, 2-spirobifluorene, 3-spirobifluorene or 4-spirobifluorene.

[0130] In another preferred embodiment of the present invention, R 1 Identical or different in each case and selected from H, D, F, CN, a straight-chain alkyl group having 1 to 10 carbon atoms or a branched or cyclic alkyl group having 3 to 10 carbon atoms, where the alkyl group may in each case be substituted by one or more R 2 groups, or an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms and which may in each case be substituted by one or more R 2 groups. In a particularly preferred embodiment of the present invention, R 1 Identical or different in each case and selected from H, a straight-chain alkyl group having 1 to 6 carbon atoms, especially 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 may be substituted by one or more R 2 groups, but is preferably unsubstituted, or an aromatic or heteroaromatic ring system having 6 to 13 aromatic ring atoms and which may in each case be substituted by one or more R 2 groups, but is preferably unsubstituted.

[0131] In another preferred embodiment of the present invention, R 2 Identical or different in each case and being: H, an alkyl group having 1 to 4 carbon atoms or an aryl group having 6 to 10 carbon atoms, where the group may be substituted by an alkyl group having 1 to 4 carbon atoms, but is preferably unsubstituted.

[0132] At the same time, in the compounds of the present invention treated by vacuum evaporation, the alkyl group preferably has no more than five carbon atoms, more preferably no more than 4 carbon atoms, and most preferably no more than 1 carbon atom. For compounds treated from solution, suitable compounds are also those compounds which are substituted by an alkyl group having at most 10 carbon atoms, especially a branched alkyl group, or those compounds which are substituted by an oligoarylene group such as o-terphenyl, m-terphenyl or p-terphenyl or a branched terphenyl or quaterphenyl group.

[0133] In a preferred configuration, the structure / compound of the present invention has been deuterated. The structure / compound of the present invention preferably has a high degree of deuteration. Preferably, the degree of deuteration is at least 50%, preferably at least 80%, particularly preferably at least 90%, and most preferably at least 95%. The degree of deuteration is determined by the numerical ratio of deuterium to the sum of deuterium and 1 H hydrogen (D / (D + H)×100). The compound is particularly preferably fully deuterated.

[0134] The compounds of the present invention are particularly suitable for use in blue-emitting electroluminescent devices. Depending on the layer, these require materials with high triplet energy levels. However, many substituents with fused aromatic or heteroaromatic groups can cause a decrease in the triplet energy level.

[0135] Therefore, relative to the anthracene structure, a naphthyl structure is preferred. In addition, relative to the naphthyl structure, fluorenyl, spirobifluorenyl, dibenzofuranyl, and / or dibenzothiophenyl structures are preferred.

[0136] Particularly preferred are non-fused structures, such as phenyl, biphenyl, terphenyl, and / or quaterphenyl structures.

[0137] It is even more preferably the case that the Ar and R groups do not contain any anthracene groups; preferably, the Ar, Ar a , R, R a , R b and R c groups do not contain any anthracene groups, and more preferably, the Ar, Ar a , R, R a , R b , R c , R 1 and R 2 groups do not contain any anthracene groups.

[0138] Very particularly preferably, it is further the case that the Ar and R groups do not contain any aromatic or heteroaromatic ring systems having three aromatic 6-membered rings fused linearly, where preferably the Ar, Ar a , R, R a , R b and R c groups do not contain any aromatic or heteroaromatic ring systems having three aromatic 6-membered rings fused linearly, and more preferably, the Ar, Ar a , R, R a , R b , R c , R 1 and R 2 groups do not contain any aromatic or heteroaromatic ring systems having three aromatic 6-membered rings fused linearly.

[0139] When the compounds of the present invention are aromatic or heteroaromatic Ra 、R b 、R c 、R 1 or R 2 When substituted by a group, it is preferred that these do not have any of the following aryl or heteroaryl groups, which have more than two aromatic six-membered rings directly fused to each other. More preferably, the substituent does not have any of the following aryl or heteroaryl groups at all, which have six-membered rings directly fused to each other. The reason for this preference is that the triplet energy of such structures is low. The fused aryl groups having more than two aromatic six-membered rings directly fused to each other but still having good applicability according to the present invention are phenanthrene and terphenylidene, because they also have high triplet energy levels.

[0140] Another possible case is that Ar, Ar a 、R、R a 、R b and R c groups do not contain or form a fluorenone group, preferably Ar, Ar a 、R、R a 、R b 、R c 、R 1 and R 2 groups do not contain or form a fluorenone group. This includes substituents bonded to groups such as Ar, Ar a 、R、R a 、R b 、R c groups. Fluorenone contains a five-membered ring having a CO group fused to two aromatic 6-membered rings.

[0141] When the compound of formula (I) or the preferred embodiment is used as a matrix material for a phosphorescent emitter or in a layer directly adjacent to the phosphorescent layer, it is also preferred that the compound does not contain any fused aryl or heteroaryl groups in which more than two six-membered rings are directly fused to each other. Phenanthrene and terphenylidene are exceptions because they have high triplet energy and can still be preferred despite the presence of fused aromatic six-membered rings.

[0142] Another possible case is that the compound contains exactly two or exactly three structures of formula (I), (I-1) to (I-11), (II-1) to (II-8), (III-1) to (III-12) and / or (IV-1) to (IV-48).

[0143] In a preferred configuration, the compound is selected from the compounds of formula (D-1),

[0144]

[0145]

[0146] wherein L 1 is a linking group, preferably a bond or an aromatic or heteroaromatic ring system having 5 to 40, preferably 5 to 30 aromatic ring atoms and being optionally substituted by one or more R a groups, and the other symbols used have the definitions given above, in particular the definitions given for formula (I), wherein the L 1 group forms a bond connecting to the basic structure in place of a hydrogen atom or a substituent; preferably, the L 1 group is bonded to the Z and A groups.

[0147] In another preferred embodiment of the present invention, L 1 is a bond or an aromatic or heteroaromatic ring system having 5 to 14 aromatic or heteroaromatic ring atoms, preferably an aromatic ring system having 6 to 12 carbon atoms, and the ring system is optionally substituted by one or more R a groups, but is preferably unsubstituted, wherein R a may have the definitions given above, in particular the definitions given for formula (I). More preferably, L 1 is an aromatic ring system having 6 to 10 aromatic ring atoms or a heteroaromatic ring system having 6 to 13 heteroaromatic ring atoms, and each of the ring systems is optionally substituted by one or more R 1 groups, but is preferably unsubstituted, wherein R 1 may have the definitions given above, in particular the definitions given for formula (I).

[0148] Also preferably, the symbol L shown in formula (D1) 1 is in each case the same or different and is a bond or an aryl or heteroaryl group having 5 to 24 ring atoms, preferably 6 to 13 ring atoms, more preferably 6 to 10 ring atoms, such that the aromatic or heteroaromatic group of the aromatic or heteroaromatic ring system is directly bonded, i.e., via an atom of the aromatic or heteroaromatic group, to the corresponding atoms of the other groups.

[0149] Another possible case is that the L 1 group in formula (D1) contains an aromatic ring system having no more than four, preferably no more than three, more preferably no more than two fused aromatic and / or heteroaromatic 6-membered rings, and preferably does not contain any fused aromatic or heteroaromatic rings.

[0150] Suitable aromatic or heteroaromatic ring systems L 1Examples are selected from: o-phenylene, m-phenylene or p-phenylene; o-biphenylene, m-biphenylene or p-biphenylene; terphenylenes, especially branched terphenylenes; quaterphenylenes, especially branched quaterphenylenes; fluorenylenes; spirobifluorenylenes; dibenzofuranylenes; dibenzothiophenylenes; and carbazolylenes, each of which groups may be substituted by one or more R 1 groups, but are preferably unsubstituted.

[0151] In a preferred configuration, the compounds of the present invention may be represented by at least one structure selected from the group consisting of formula (I), (I-1) to (I-11), (II-1) to (II-8), (III-1) to (III-12) and / or (IV-1) to (IV-48). Preferably, the molecular weight of the compounds of the present invention preferably comprising the structures of formula (I), (I-1) to (I-11), (II-1) to (II-8), (III-1) to (III-12) and / or (IV-1) to (IV-48) is not greater than 5000 g / mol, preferably not greater than 4000 g / mol, particularly preferably not greater than 3000 g / mol, especially preferably not greater than 2000 g / mol, more especially preferably not greater than 1200 g / mol, and most preferably not greater than 900 g / mol.

[0152] In addition, a feature of the preferred compounds of the present invention is that they are sublimable. The molar mass of these compounds is generally less than about 1200 g / mol.

[0153] It is also possible that the compounds comprising the structure of formula (I), preferably the compounds of formula (I) or the preferred embodiments of this structure / compound, are not in direct contact with metal atoms and are preferably not ligands of metal complexes.

[0154] The preferred embodiments mentioned above can be combined with each other as needed within the scope of the limitations defined in claim 1. In a particularly preferred embodiment of the present invention, the preferred options mentioned above occur simultaneously.

[0155] Examples of preferred compounds according to the embodiments described in detail above are the compounds detailed in the following table:

[0156]

[0157]

[0158]

[0159]

[0160]

[0161]

[0162]

[0163]

[0164]

[0165]

[0166]

[0167]

[0168]

[0169] The basic structure of the compounds of the present invention can be prepared by the routes outlined in the following schemes. Each of the synthetic steps herein, such as the coupling reactions that cause C-C bond formation and / or C-N bond formation, are in principle known to those skilled in the art. These include the Buchwald, Suzuki, Yamamoto, Stille, Heck, Negishi, Sonogashira, and Hiyama reactions.

[0170] Other information related to the synthesis of the compounds of the present invention can be found in the synthesis examples.

[0171] The following scheme describes by way of example the preparation of the compound of formula (I-1) of the present invention, such that other compounds of the present invention, especially the compounds of formula (I-2) to (I-11), can be obtained by analogous synthetic routes starting from different parent structures. For this purpose, the examples describing the compounds of formula (I-2) and (I-3) are specifically referred to. Those skilled in the art will use the corresponding amine compounds for the preparation of the compounds of formula (I-4) to (I-11).

[0172] For example, starting from starting materials in the form of N-benzylated 2-chloroimidazole (1) and aniline (2) known from the literature, the compounds of the present invention can be prepared in three steps (Scheme 1).

[0173] First, these were converted to N,N-dibenzylated bis(2-imidazolyl)amine (3) in m-xylene at 120 °C in the presence of lithium tert-butoxide in Stage 1 according to W. Sang et al., Adv. Synth. Catal., 2021, 363, 1408. Subsequently, the benzyl protecting groups were removed by the action of potassium tert-butoxide and oxygen in DMSO / THF (Stage 2) according to A. A. Haddach et al., Tetrahedron Letters, 2002, 43, 399, to give free bis(2-imidazolyl)amine (4). Alternatively, the removal can be carried out by a hydrogenolysis reaction known to those skilled in the art, for example, by hydrogenolysis in a tetrahydrofuran / methanol / Pd-carbon / H 2 system.

[0174] Finally, in Stage 3, bis(2-imidazolyl)amine (4) was deprotonated with n-BuLi and then coupled with an electrophile E. The electrophiles used can be dihalides such as RBCl 2 、R 2 CCl 2 、R 2 SiCl 2 、R 2 GeCl 2 、SiCl 4 、GeCl 4 、RP(O)Cl 2 、SO 2 Cl 2 、SeO 2 Cl 2 (R = alkyl, aryl, heteroaryl).

[0175] Scheme 1:

[0176]

[0177] N-Benzylated 2-chloroimidazole and N-benzylated 3-chloropyrazole, as well as N-benzylated 3-chlorobenzopyrazole can be similarly converted.

[0178] Starting from 2,2'-oxoimidazole or 2,2'-thioimidazole or 2,2'-oxobenzimidazole or 2,2'-thiobenzimidazole (6) known from the literature, the compounds of the present invention (7) can be obtained (Scheme 2).

[0179] Scheme 2:

[0180]

[0181] The definitions of the symbols used in the above-presented scheme essentially correspond to those for formula (I). For the sake of clarity, all symbol numbers and full representations are omitted.

[0182] Accordingly, the present invention also provides a method for preparing the compounds of the present invention, wherein a basic skeleton having an aromatic amino group is synthesized, and at least one aromatic or heteroaromatic group is introduced, preferably by nucleophilic aromatic substitution reaction or coupling reaction to introduce at least one aromatic or heteroaromatic group.

[0183] In a preferred configuration of the method, it is feasible that at least one aromatic or heteroaromatic group is an imidazole or benzimidazole compound, wherein the imidazole or benzimidazole compound is symmetric with respect to two nitrogen atoms.

[0184] This configuration can particularly prevent the formation of isomers because the intermediates detailed above can exhibit tautomerism.

[0185] By these methods, if necessary, subsequent purification, such as recrystallization or sublimation, can be carried out, so that the compounds of the present invention with high purity, preferably greater than 99% (determined by 1 1H NMR and / or HPLC) can be obtained.

[0186] The compounds of the present invention can also be mixed with polymers. Similarly, these compounds can be covalently incorporated into polymers. This is particularly applicable to compounds substituted by reactive leaving groups such as bromine, iodine, chlorine, boric acid or borate, or by reactive polymerizable groups such as olefins or oxetanes. It has been found that these can be used as monomers for manufacturing corresponding oligomers, dendrimers or polymers. Oligomerization or polymerization is preferably achieved via halogen functional groups or boric acid functional groups or via polymerizable groups. In addition, the polymer can be crosslinked via such groups. The compounds of the present invention and polymers can be used in the form of crosslinked or uncrosslinked layers.

[0187] Accordingly, the present invention also provides an oligomer, polymer or dendrimer containing one or more structures of formula (I) detailed above and the preferred embodiments of this formula or the compounds of the present invention, wherein there are one or more bonds connecting the compounds of the present invention or the structures of formula (I) and the preferred embodiments of this formula to the polymer, oligomer or dendrimer. Depending on the connection of the structure of formula (I) and the preferred embodiments of this formula or the compound, these thus form side chains of the oligomer or polymer or are bonded within the main chain. The polymer, oligomer or dendrimer can be conjugated, partially conjugated or non-conjugated. The oligomer or polymer can be linear, branched or dendritic. The same preferred options as described above apply to the repeating units of the compounds of the present invention in the oligomers, dendrimers and polymers.

[0188] To prepare oligomers or polymers, the monomers of the present invention are homopolymerized or copolymerized with other monomers. Preferred copolymers are those in which the units of formula (I) or the preferred embodiments described above and below are present in a range of 0.01 mol% to 99.9 mol%, preferably 5 mol% to 90 mol%, more preferably 20 mol% to 80 mol%. Suitable and preferred comonomers for forming the polymer backbone are selected from: fluorene (e.g., according to EP 842208 or WO 2000 / 022026), spirobifluorene (e.g., according to EP 707020, EP 894107 or WO 2006 / 061181), phenylene (e.g., according to WO 92 / 18552), carbazole (e.g., according to WO 2004 / 070772 or WO 2004 / 113468), thiophene (e.g., according to EP 1028136), dihydrophenanthrene (e.g., according to WO 2005 / 014689), cis- and trans-indeno[1,2-b]fluorene (e.g., according to WO 2004 / 041901 or WO 2004 / 113412), ketone (e.g., according to WO 2005 / 040302), phenanthrene (e.g., according to WO 2005 / 104264 or WO 2007 / 017066) or a plurality of other such units. Polymers, oligomers and dendrimers may also contain other units, such as: hole transport units, especially those based on triarylamine; and / or electron transport units.

[0189] In addition, of particular interest are the compounds of the present invention which are characterized by a high glass transition temperature. In this regard, particularly preferred are the compounds of the present invention comprising the structure of formula (I) or the preferred embodiments described above and below, having a glass transition temperature of at least 70 °C, more preferably at least 110 °C, even more preferably at least 125 °C, particularly preferably at least 150 °C, as measured according to DIN 51005 (version 2005-08).

[0190] To process the compounds of the present invention from the liquid phase, for example by spin coating or by printing methods, formulations of the compounds of the present invention are required. These formulations can be, for example, solutions, dispersions or emulsions. For this purpose, a mixture of two or more solvents can preferably be used. Suitable and preferred solvents are, for example, toluene, anisole, o-xylene, m-xylene or p-xylene, methyl benzoate, mesitylene, decalin, o-dimethoxybenzene, THF, methyl-THF, THP, chlorobenzene, di Alkanes, phenoxytoluenes, 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, butyl benzoate, cumene, cyclohexanol, cyclohexanone, cyclohexylbenzene, decalin, dodecylbenzene, ethyl benzoate, indane, NMP, p - cymene, phenetole, 1,4 - diisopropylbenzene, dibenzyl ether, diethylene glycol monobutyl methyl ether, triethylene glycol monobutyl 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, menthyl isovalerate, cyclohexyl hexanoate, or a mixture of these solvents.

[0191] Accordingly, the present invention also provides a formulation or composition, which comprises at least one compound of the present invention and at least one other compound. The other compound can be, for example, a solvent, especially one of the above solvents or a mixture of these solvents. If the other compound comprises a solvent, the mixture is referred to herein as a formulation. The other compound can alternatively be at least one other organic or inorganic compound also used in electronic devices, such as a luminescent compound and / or other matrix materials. Preferably, it is feasible that at least one other compound is selected from fluorescent emitters, phosphorescent emitters, emitters showing TADF, host materials, electron transport materials, electron injection materials, hole conduction materials, hole injection materials, electron blocking materials, and hole blocking materials, preferably host materials.

[0192] The present invention also provides the use of the compounds of the present invention in electronic devices, especially in organic electroluminescent devices. Preferably, it is feasible that the compounds of the present invention are used as host materials, electron transport materials, electron injection materials, hole conduction materials, hole injection materials, electron blocking materials, and hole blocking materials in electronic devices.

[0193] Furthermore, it is feasible that the compounds of the present invention are used as host materials, electron transport materials, electron injection materials, or hole blocking materials, and the compounds of the present invention comprise at least one electron transport group and / or one electron - withdrawing group, where the preferred electron transport groups and / or electron - withdrawing groups have been defined above.

[0194] Another possible situation is that the compound of the present invention is used as a host material, a hole-conducting material, a hole-injecting material or an electron-blocking material, and the compound of the present invention contains at least one hole-transporting group, wherein the preferred electron-transporting group and / or electron-withdrawing group have been defined above.

[0195] Another possible situation is that the compound of the present invention is used as a host material, and the compound of the present invention contains at least one hole-transporting group and at least one electron-transporting group and / or electron-withdrawing group.

[0196] The present invention further provides an electronic device, which comprises at least one compound of the present invention. An electronic device in the context of the present invention is a device that contains at least one layer containing at least one organic compound. The assembly may also contain inorganic materials or other layers formed entirely of inorganic materials.

[0197] The electronic device is more preferably selected from: organic electroluminescent devices (OLED, sOLED, PLED, LEC, etc.), preferably organic light-emitting diodes (OLED), small molecule-based organic light-emitting diodes (sOLED), polymer-based organic light-emitting diodes (PLED), light-emitting electrochemical cells (LEC), organic laser diodes (O-lasers), organic plasma light-emitting devices (D.M. Koller et al., Nature Photonics 2008, 1-4), organic integrated circuits (O-IC), organic field-effect transistors (O-FET), organic thin-film transistors (O-TFT), organic light-emitting transistors (O-LET), organic solar cells (O-SC), organic optical detectors, organic photoreceptors, organic field quenching devices (O-FQD) and organic electrical sensors, preferably organic electroluminescent devices (OLED, sOLED, PLED, LEC, etc.), more preferably organic light-emitting diodes (OLED), small molecule-based organic light-emitting diodes (sOLED), polymer-based organic light-emitting diodes (PLED), especially phosphorescent OLED.

[0198] The organic electroluminescent device comprises a cathode, an anode and at least one light-emitting layer. In addition to these layers, the organic electroluminescent device may also comprise other 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 having, for example, an exciton blocking function may also be introduced between two light-emitting layers. However, it should be noted that not every one of these layers necessarily exists. In this case, the organic electroluminescent device may contain one light-emitting layer, or it may contain a plurality of light-emitting layers. If a plurality of light-emitting layers are present, it is preferred that these light-emitting layers have a plurality of emission peaks in total between 380 nm and 750 nm, such that the overall result is white emission; in other words, a plurality of light-emitting compounds that can emit fluorescence or phosphorescence are used in the light-emitting layer. A system having three light-emitting layers is particularly preferred, wherein the three layers exhibit blue, green and orange or red emission. The organic electroluminescent device of the present invention may also be a tandem electroluminescent device, especially a white-emitting OLED.

[0199] The compounds of the present invention can be used in different layers according to the exact structure. It is preferred that the organic electroluminescent device comprises a compound of formula (I) or a compound of the above preferred embodiment in the light-emitting layer as a host material for a fluorescent emitter, a phosphorescent emitter or an emitter exhibiting TADF (thermally activated delayed fluorescence), especially as a host material for a phosphorescent emitter. In addition, the compounds of the present invention can also be used in the electron transport layer, the electron injection layer and / or the hole transport layer, the hole injection layer and / or the exciton blocking layer and / or the hole blocking layer. More preferably, the compounds of the present invention are used as a matrix material for a phosphorescent emitter in the light-emitting layer, especially as a matrix material for a red phosphorescent, orange phosphorescent, green phosphorescent, yellow phosphorescent or blue phosphorescent emitter, as an electron transport material or a hole blocking material in the electron transport layer or the hole blocking layer, or as a hole transport material or an electron blocking material in the hole transport layer or the electron blocking layer. The applicability of various compounds of formula (I) has been shown above in connection with the preferred uses.

[0200] When the compounds of the present invention are used as a matrix material for a phosphorescent compound in the light-emitting layer, they are preferably used in combination with one or more phosphorescent materials (triplet emitters).

[0201] In the context of the present invention, phosphorescence should be understood to mean emission from an excited state with a higher spin multiplicity, i.e., spin state > 1, especially emission from an excited triplet state. In the context of the present application, all luminescent complexes having transition metals or lanthanide elements, especially all iridium, platinum and copper complexes, should be considered phosphorescent compounds.

[0202] Based on the overall mixture of the light emitter and the matrix material, the mixture of the compound of the present invention and the light-emitting compound contains between 99 vol% and 1 vol%, preferably between 98 vol% and 10 vol%, more preferably between 97 vol% and 60 vol%, especially between 95 vol% and 80 vol% of the compound of the present invention. Correspondingly, based on the overall mixture of the light emitter and the matrix material, the mixture contains between 1 vol% and 99 vol%, preferably between 2 vol% and 90 vol%, more preferably between 3 vol% and 40 vol%, especially between 5 vol% and 20 vol% of the light emitter.

[0203] In one embodiment of the present invention, the compound of the present invention is herein used as the sole matrix material ("single host") for the phosphorescent emitter.

[0204] Another embodiment of the present invention is to combine the compounds of the present invention with other host materials for use as host materials for phosphorescent emitters. Suitable host materials that can be used in combination with the compounds of the present invention are aromatic ketones, aromatic phosphine oxides, or aromatic sulfoxides or sulfones, such as those according to WO 2004 / 013080, WO 2004 / 093207, WO 2006 / 005627 or WO2010 / 006680; triarylamines; carbazole derivatives, such as CBP (N,N-dicarbazolylbiphenyl) or carbazole derivatives disclosed in WO 2005 / 039246, US2005 / 0069729, JP 2004 / 288381, EP 1205527, WO 2008 / 086851 or WO 2013 / 041176; indolocarbazole derivatives, such as those according to WO 2007 / 063754 or WO 2008 / 056746; indacarbazole derivatives, such as those according to WO 2010 / 136109, WO 2011 / 000455, WO 2013 / 041176 or WO 2013 / 056776; azacarbazole derivatives, such as those according to EP 1617710, EP1617711, EP 1731584, JP2005 / 347160; bipolar host materials, such as those according to WO 2007 / 137725; silanes, such as those according to WO 2005 / 111172; borazoles or borates, such as those according to WO 2006 / 117052; triazine derivatives, such as those according to WO2007 / 063754, WO 2008 / 056746, WO 2010 / 015306, WO 2011 / 057706, WO 2011 / 060859 or WO2011 / 060877; zinc complexes, such as those according to EP 652273 or WO 2009 / 062578; siladiazoles or silatetrazoles derivatives, such as those according to WO 2010 / 054729; phosphadiazoles derivatives, such as those according to WO2010 / 054730; bridged carbazole derivatives, such as those according to WO 2011 / 042107, WO 2011 / 060867, WO 2011 / 088877 and WO 2012 / 143080; terphenylidene derivatives, such as those according to WO 2012 / 048781; dibenzofuran derivatives, such as those according to WO 2015 / 169412, WO 2016 / 015810, WO 2016 / 023608, WO 2017 / 148564 or WO2017 / 148565; or bi-carbazole, such as those according to JP 3139321B2.

[0205] In a preferred configuration, the compound containing the compound of formula (I) or the structure / compound of the above preferred embodiments used as the host material is preferably:

[0206] - combined with one or more phosphorescent materials (triplet emitters); and / or

[0207] - combined with one or more fluorescent materials; and / or

[0208] - combined with a compound having TADF properties, where TADF represents "thermally activated delayed fluorescence".

[0209] Here, a hyperfluorescent system as described in WO 2012 / 133188 and / or a hyperphosphorescent system as described in US 2017271611 is preferably formed. This combination is a preferred embodiment according to the present invention.

[0210] WO 2015 / 091716 A1 and WO 2016 / 193243 A1 disclose OLEDs containing both a phosphorescent compound and a fluorescent emitter in the light-emitting layer, where energy is transferred from the phosphorescent compound to the fluorescent emitter (hyperphosphorescence). As is known to those skilled in the art, the host material has a higher singlet energy and triplet energy than the emitter, so that the energy from the host material will also be transferred to the emitter with maximum efficiency. The systems disclosed in the prior art exactly have this energy relationship.

[0211] The present invention also relates to an electronic device containing an organic layer, preferably a light-emitting layer, where the organic layer contains:

[0212] - a compound containing the compound of formula (I) or the structure / compound of the above preferred embodiments as the host material;

[0213] - an optional second compound as a co-host material;

[0214] - a photosensitizer; and

[0215] - a fluorescent emitter,

[0216] where the photosensitizer is a phosphorescent compound (triplet emitter) or a TADF compound.

[0217] Preferred emitters that can be used in combination with the compounds of the present invention are particularly described in Sungho Nam et al., Adv. Sci. 2021, 2100586 and Eungdo Kin et al., Sci. Adv. 2022, 8, 1641. Preferred triplet emitters or triplet emitter classes, also referred to as photosensitizers related to hyperphosphorescent systems, are also described in EP 3 435 438 A2, where emitter 2 and emitter 3 on page 21 are preferred; in CN 109111487, where the compounds shown on pages 76 and 77 are preferred; in US2020 / 0140471, where the compounds shown on pages 166 to 175 are preferred; in KR2020108705, where the compounds shown on pages 8 to 14 are preferred; in US2019 / 0119312, where the compounds shown on pages 114 to 121 are preferred; and in US2020 / 0411775, where the compounds shown on pages 123 to 128 are preferred. In addition, preferred fluorescent emitters or fluorescent emitter classes are described in the following documents: in WO 2021 / 090932, where the compounds shown on pages 129 to 133, 157 to 166, 171 to 187, 200 to 211, 222 to 227, 236 to 252, 255 are preferred; in WO 2020 / 054676, where the compounds shown on pages 44 to 104 are preferred; in WO 2020 / 017931, where the compounds shown on pages 17 to 39 are preferred; in WO 2020 / 218079, where the compounds shown on pages 64 to 258 are preferred; in WO 2018 / 212169, where the compounds shown on pages 33 to 42 are preferred; in WO 2019 / 235452, where the compounds shown on pages 46 to 168 are preferred; in US10,249,832, where the compounds shown on pages 19 to 106 are preferred; and in WO 2021 / 014001, where the compounds shown on pages 107 to 129 are preferred.

[0218] It is also feasible that other phosphorescent emitters that emit light at wavelengths shorter than the wavelength of the actual emitter are present in the mixture as co-host materials. Particularly good results are achieved when the emitter used is a red phosphorescent emitter and the co-host material used in combination with the compounds of the present invention is a yellow phosphorescent emitter.

[0219] In addition, the co-host material used may be a compound that, even though it participates in charge transport, does not participate to a significant extent, as described, for example, in WO 2010 / 108579. Particularly suitable as co-host materials in combination with the compounds of the present invention are compounds having a large bandgap and that, even though they participate in charge transport in the light-emitting layer, do not participate at least to a significant extent. Such materials are preferably pure hydrocarbons. Examples of such materials can be found, for example, in WO 2009 / 124627 or WO 2010 / 006680. In this context, it should be emphasized that the compounds of the present invention have advantageous properties in the absence of specific functional groups such as hole-transporting groups and / or electron-transporting groups.

[0220] Suitable phosphorescent compounds ( = triplet emitters) are in particular compounds that emit light when appropriately excited, preferably in the visible region; and that also contain at least one atom having an atomic number greater than 20, preferably greater than 38 and less than 84, more preferably greater than 56 and less than 80, in particular a metal having that atomic number. Preferred phosphorescent emitters used are compounds containing copper, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, iridium, palladium, platinum, silver, gold or europium, in particular compounds containing iridium or platinum.

[0221] Examples of such light emitters can be found in the following applications: WO 00 / 70655, WO 2001 / 41512, WO2002 / 02714, WO 2002 / 15645, EP 1191613, EP 1191612, EP 1191614, WO 05 / 033244, WO 05 / 019373, US2005 / 0258742, WO 2009 / 146770, WO 2010 / 015307, WO 2010 / 031485, WO 2010 / 054731, WO 2010 / 054728, WO 2010 / 086089, WO 2010 / 099852, WO 2010 / 102709, WO 2011 / 032626, WO 2011 / 066898, WO 2011 / 157339, WO 2012 / 007086, WO 2014 / 008982, WO 2014 / 023377, WO 2014 / 094961, WO 2014 / 094960, WO 2015 / 036074, WO 2015 / 104045, WO 2015 / 117718, WO 2016 / 015815, WO 2016 / 124304, WO 2017 / 032439, and WO 2018 / 011186. Generally, all phosphorescent complexes for phosphorescent electroluminescent devices according to the prior art and known to the person skilled in the art of organic electroluminescence are suitable, and the person skilled in the art will be able to use other phosphorescent complexes without creative effort.

[0222] Examples of phosphorescent dopants are listed in the following table:

[0223]

[0224]

[0225]

[0226]

[0227]

[0228] The compounds of the present invention are also particularly suitable as host materials for phosphorescent light emitters in organic electroluminescent devices, as described, for example, in WO 98 / 24271, US2011 / 0248247, and US 2012 / 0223633. In these multicolor display assemblies, an additional blue light-emitting layer is applied by vapor deposition over the entire area to all pixels, including those having non-blue colors.

[0229] In another embodiment of the present invention, the organic electroluminescent device of the present invention does not contain any separate hole injection layer and / or hole transport layer and / or hole blocking layer and / or electron transport layer, which means that the light-emitting layer is directly adjacent to the hole injection layer or the anode, and / or the light-emitting layer is directly adjacent to the electron transport layer or the electron injection layer or the cathode, as described, for example, in WO2005 / 053051. Additionally, a metal complex that is the same as or similar to the metal complex in the light-emitting layer can be used as the hole transport or hole injection material directly adjacent to the light-emitting layer, as described, for example, in WO 2009 / 030981.

[0230] In other layers of the organic electroluminescent device of the present invention, any materials commonly used according to the prior art can be used. Therefore, those skilled in the art will be able to combine any known materials for organic electroluminescent devices with the compounds of the present invention of formula (I) or the above-described preferred embodiments without creative efforts.

[0231] Additionally preferred is an organic electroluminescent device, which is characterized in that one or more layers are coated by sublimation. In this case, the material is applied by vapor deposition in a vacuum sublimation system at an initial pressure of less than 10 -5 mbar, preferably less than 10 -6 mbar. However, the initial pressure can even be lower, for example, less than 10 -7 mbar.

[0232] Also preferred is an organic electroluminescent device, which is characterized in that one or more layers are coated by OVPD (organic vapor deposition) method or by carrier gas sublimation. In this case, the material is applied at a pressure between 10 -5 mbar and 1 bar. A special case of this method is the OVJP (organic vapor jet printing) method, in which the material is directly applied through a nozzle and thus structured.

[0233] Additionally preferred is an organic electroluminescent device, which is characterized in that one or more layers are produced from a solution, for example, by spin coating, or by any printing method such as screen printing, flexographic printing, offset printing, LITI (light-induced thermal imaging, thermal transfer), inkjet printing or nozzle printing. For this purpose, soluble compounds obtained, for example, by suitable substitution are required.

[0234] The preparation containing the compound of formula (I) or its preferred embodiments detailed above is new. Therefore, the present invention also provides a preparation containing at least one solvent and the compound of formula (I) or its preferred embodiments detailed above.

[0235] In addition, hybrid methods are feasible, for example, where one or more layers are applied from a solution and one or more other layers are applied by vapor deposition.

[0236] These methods are generally known to those skilled in the art and can be applied to organic electroluminescent devices containing the compounds of the present invention without creative effort.

[0237] The compounds of the present invention and the organic electroluminescent devices of the present invention are particularly characterized by improved efficiency and / or operating voltage compared to the prior art. In addition, these compounds and the organic electroluminescent devices obtainable therefrom exhibit improved lifetime. In a particular variant, compared to the prior art, the compounds of the present invention and the organic electroluminescent devices of the present invention are particularly characterized by a low refractive index (RI). In addition, the preferred compounds of the present invention exhibit a high triplet T1 energy level, and thus these compounds are particularly suitable as host materials for triplet emitters for blue emission.

[0238] The electronic devices of the present invention, in particular organic electroluminescent devices, have one or more of the following surprising advantages compared to the prior art:

[0239] 1. An electronic device, in particular an organic electroluminescent device, comprising a compound of formula (I) or a preferred embodiment described in the context, in particular as a matrix material, as an electron-conducting material or as a hole-conducting material, has excellent efficiency. In this case, the compound of the present invention of formula (I) or a preferred embodiment described in the context brings a low operating voltage when used in an electronic device.

[0240] 2. An electronic device, in particular an organic electroluminescent device, comprising a compound of formula (I) or a preferred embodiment described in the context, in particular as a matrix material, as an electron-conducting material or as a hole-conducting material, has a very good lifetime. In this case, these compounds in particular bring a low roll-off, i.e., a small decrease in the power efficiency of the device at high emission densities.

[0241] 3. The compounds of the present invention of formula (I) or a preferred embodiment described in the context exhibit very high stability and lifetime.

[0242] 4. An electronic device, in particular an organic electroluminescent device, comprising a compound of formula (I) or a preferred embodiment described in the context, in particular as a matrix material, as an electron-conducting material or as a hole-conducting material, has a high T1 energy level.

[0243] 5. By using the compounds of formula (I) or the preferred embodiments described in the context, the formation of optical loss channels in electronic devices, especially organic electroluminescent devices, can be avoided. As a result, these devices are characterized by high PL efficiency of the lumophore and thus high EL efficiency, and excellent energy transfer from the matrix to the dopant.

[0244] 6. The compounds of formula (I) or the preferred embodiments described in the context have excellent glass film formation.

[0245] 7. The compounds of formula (I) or the preferred embodiments described in the context form very good films from solutions.

[0246] These above-mentioned advantages are not accompanied by very serious deterioration of other electronic properties.

[0247] It should be noted that the scope of the present invention covers variations of the embodiments described in the present invention. Unless any feature disclosed in the present invention is explicitly excluded, it can be exchanged with alternative features having the same purpose or equivalent or similar purposes. Therefore, unless otherwise specified, any feature disclosed in the present invention should be regarded as an instance of a general series or equivalent or similar features.

[0248] Unless specific features and / or steps are mutually exclusive, all features of the present invention can be combined with each other in any way. This is especially true for the preferred features of the present invention. Similarly, features that are not necessarily combined can be used individually (rather than in combination).

[0249] It should also be noted that many features of the present invention, especially those of the preferred embodiments, should be considered to be inventive in themselves, rather than just as some embodiments of the present invention. For these features, independent protection can be sought as a supplement or alternative to any currently claimed invention.

[0250] The technical teachings disclosed in the present invention can be refined and combined with other embodiments.

[0251] The present invention is exemplified in detail by the following examples, but is by no means intended to limit the present invention thereby. Those skilled in the art will be able to implement the present invention within the entire scope disclosed by using the information given without creative efforts, prepare other compounds of the present invention and use them in electronic devices, or adopt the methods of the present invention. Examples

[0252] Unless otherwise stated, the following syntheses are carried out in a dry solvent under a protective gas atmosphere. The metal complexes require additional handling in the dark or under yellow light. Solvents and reagents are commercially available, for example, from Sigma-ALDRICH or ABCR. The corresponding numbers in square brackets or the numbers cited for individual compounds are related to the CAS numbers of the compounds known from the literature. In the case of compounds that can exist in multiple enantiomeric, diastereomeric or tautomeric forms, one form is shown in a representative manner.

[0253] A) Preparation of synthon S

[0254] Example S1:

[0255]

[0256] a) Stage 1:

[0257] The procedure is similar to that of W. Sang et al., Adv. Synth. Catal., 2021, 363, 1408, see page 1415 "The LiOtBu promoted reactions". Starting materials: 5.34 g (22 mmol) of 2-chloro-1-(phenylmethyl)-1H-benzimidazole [43181-78-8], 931 mg (10 mmol) of aniline [62-53-3], 3.20 g (40 mmol) of lithium tert-butoxide [1907-33-1], 20 ml of m-xylene, 30 h, 120 °C. The volatile components are removed under reduced pressure and chromatographic purification is carried out (Torrent automatic chromatography column system from A. Semrau). Yield: 3.85 g (7.6 mmol), 76%; purity: approximately 97%, according to 1 1H NMR.

[0258] b) Stage 2:

[0259] The procedure is similar to that of A. A. Haddach et al., Tetrahedron Letters 43 (2002) 399–402, see page 401, item 7. Starting materials: 5.06 g (10 mmol) of the product from Stage 1, 140 ml of a 1 M solution of potassium tert-butoxide in THF, 200 ml of DMSO, 25 °C, oxygen is introduced with vigorous stirring for 20 min and then quenched with 200 ml of saturated ammonium chloride solution, and the extraction work-up (ethyl acetate: water) is carried out. Chromatographic separation of the crude product is carried out (Torrent automatic chromatography column system from A. Semrau). Yield: 2.11 g (6.4 mmol), 64%; purity: approximately 97%, according to 1 1H NMR.

[0260] c) Stage 2: Alternative hydrogenolysis variant

[0261] The process is similar to that of T.H. Graham et al., Tetrahedron Letters (2015), 56(21), 2688. Alternatively, hydrogen gas (1 - 5 bar) can be used instead of triethylsilane.

[0262] The following compounds can be prepared similarly:

[0263]

[0264]

[0265]

[0266]

[0267]

[0268]

[0269]

[0270]

[0271]

[0272]

[0273] B) Preparation examples of the compounds of the present invention Example B1:

[0274]

[0275] At -78 °C, 12.5 ml (20 mmol) of 1.6 M n-BuLi in n-hexane was added dropwise to a solution of 3.25 g (10 mmol) of S1 in 100 ml of THF, and the mixture was stirred for an additional 30 minutes. Subsequently, a solution of 1.59 g (10 mmol) of dichlorophenylborane [873-51-8] in 30 ml of THF was added dropwise, and the mixture was stirred for an additional 1 hour and then allowed to warm gradually to room temperature. After 12 hours, THF was removed under reduced pressure, the residue was dissolved in 50 ml of dichloromethane, lithium chloride was filtered off, the filtrate was adsorbed on an Isolute column and chromatographed (Torrent automated chromatography column system from A. Semrau). The product thus obtained was purified by repeated hot extraction crystallization (conventional organic solvents or combinations thereof, preferably acetonitrile-DCM, 1:3 to 1:1, volume:volume) and fractional sublimation or heat treatment under high vacuum. Yield: 2.91 g (7.1 mmol), 71%; Purity: approximately 99.9%, according to HPLC.

[0276] The following compounds can be prepared analogously, adjusting the respective stoichiometry of the reactants used, and the yields are generally 40% - 90%:

[0277]

[0278]

[0279]

[0280]

[0281]

[0282]

[0283]

[0284]

[0285]

[0286]

[0287]

[0288]

[0289]

[0290]

[0291]

[0292]

[0293]

[0294]

[0295] Example: Fabrication of OLED

[0296] 1) Vacuum-processed devices:

[0297] The OLEDs of the present invention and those according to the prior art are fabricated by a general method according to WO 2004 / 058911, adjusting the method to suit the circumstances described herein (layer thickness, variations in materials used).

[0298] In the following examples, results of various OLEDs are presented. Clean glass plates coated with 50 nm thick structured ITO (indium tin oxide) (cleaned in a Miele laboratory glass washer, Merck Extran detergent) are pre-treated with UV ozone for 25 minutes (UVP PR-100 UV ozone generator). These coated glass plates form the substrates on which the OLEDs are applied.

[0299] 1a) Blue fluorescent OLED assembly - BF:

[0300] The compounds of the present invention can be used in the hole injection layer (HIL), hole transport layer (HTL), and electron blocking layer (EBL). All materials are applied by hot vapor deposition in a vacuum chamber. Here, the emissive layer (EML) always consists of at least one matrix material (host material) SMB (see Table 1) and an emissive dopant (dopant, emitter) D, and the emissive dopant is added to one or more matrix materials by co-evaporation in a specific volume ratio. Details given in the form of, for example, SMB:D (97:3%) mean that the material SMB is present in the layer in a volume ratio of 97% and the dopant D is present in the layer in a volume ratio of 3%. Similarly, the electron transport layer can also consist of a mixture of two materials; see Table 1. The materials used for producing the OLEDs are shown in Table 5 or are related to the synthesis examples detailed above.

[0301] The OLEDs are characterized in a standard manner. For this purpose, the electroluminescence spectrum is determined, and the current efficiency (measured in cd / A), power efficiency (measured in lm / W), and external quantum efficiency (EQE, measured in %) as a function of the luminescence density are calculated from the current-voltage-luminescence density characteristics (IUL characteristics) assuming Lambertian emission characteristics, and the lifetime is also determined. At 1000 cd / m2 Report the EQE in (%) and the voltage in (V) at a luminous density of 10000 cd / m 2 Measure the lifetime at the initial luminous density. Set the measurement period during which the luminance of the reference decreases to 80% of its initial luminance to 100%. Report the lifetime of the OLED component containing the compound of the present invention as a percentage relative to the reference.

[0302] The OLED has the following layer structure:

[0303] Substrate

[0304] A hole injection layer (HIL) composed of HTM1 doped with 5% NDP-9 (available from Novaled), 20 nm

[0305] Hole transport layer (HTL), see Table 1

[0306] Electron blocking layer (EBL), see Table 1

[0307] Emission layer (EML), see Table 1

[0308] Electron transport layer (ETL), see Table 1

[0309] An electron injection layer (EIL) composed of ETM2, 1 nm

[0310] A cathode composed of aluminum, 100 nm

[0311] Table 1: Structure of the blue fluorescent OLED component

[0312]

[0313]

[0314] Table 2: Results of the blue fluorescent OLED component

[0315]

[0316] 1b) Phosphorescent OLED component:

[0317] The compound A of the present invention can be used as a matrix material (host material) M (see Table 5) or A (see the materials of the present invention) in the hole injection layer (HIL), hole transport layer (HTL), electron blocking layer (EBL), and emission layer (EML). For this purpose, all materials are applied by hot vapor deposition in a vacuum chamber. Here, the emission layer always consists of at least one or more than one matrix material M and a phosphorescent dopant Ir, and the phosphorescent dopant Ir is added to one or more matrix materials by co-evaporation in a specific volume ratio. The details given in the form of, for example, M1:M2:Ir (55%:35%:10%) mean that the material M1 is present in the layer in a volume ratio of 55%, M2 is present in the layer in a volume ratio of 35%, and Ir is present in the layer in a volume ratio of 10%. Similarly, the electron transport layer can also be composed of a mixture of two materials. The exact structure of the OLED can be found in Table 3. The materials used for producing the OLED are shown in Table 5 or are related to the synthesis examples detailed above.

[0318] The OLED is characterized in a standard manner. For this purpose, the electroluminescence spectrum is determined, and the current efficiency (measured in cd / A), power efficiency (measured in lm / W), and external quantum efficiency (EQE, measured in %) as a function of the emission density are calculated from the current-voltage-emission density characteristic (IUL characteristic) assuming Lambertian emission characteristics, and the lifetime is also measured. The EQE in (%) and the voltage in (V) are reported at an emission density of 1000 cd / m 2 The lifetime is measured at the initial emission density of 1000 cd / m for blue and red, and at the initial emission density of 10000 cd / m for green and yellow. The measurement period when the brightness of the reference drops to 80% of its initial brightness is set to 100%. The lifetime of the OLED component containing the compound of the present invention is reported as a percentage relative to the reference. 2 2

[0319] The OLED has the following layer structure:

[0320] Substrate

[0321] A hole injection layer (HIL) composed of HTM1 doped with 5% NDP-9 (available from Novaled), 20 nm

[0322] Hole transport layer (HTL), see Table 3

[0323] Electron blocking layer (EBL), see Table 3

[0324] Emission layer (EML), see Table 3

[0325] ​​Hole Blocking Layer (HBL), see Table 3

[0326] Electron Transport Layer (ETL), composed of ETM1:ETM2 (50%:50%), 30 nm

[0327] Electron Injection Layer (EIL) composed of ETM2, 1 nm

[0328] Cathode made of aluminum, 100 nm

[0329] Table 3: Structure of Phosphorescent OLED Components

[0330]

[0331]

[0332]

[0333] Table 4: Results for Phosphorescent OLED Components

[0334]

[0335]

[0336] Table 5: Structural Formulas of the Materials Used

[0337]

[0338]

[0339]

[0340]

Claims

1. A compound, the compound comprising at least one structure of formula (I), wherein the symbols are as follows: A is the same or different in each case and is B(R), B(Ar), P(R)O, P(Ar)O, C(R) 2 , C(Ar) 2 , Si(R) 2 , Si(Ar) 2 , Ge(R) 2 , Ge(Ar) 2 , Ti(R) 2 , Ti(Ar) 2 , Zr(R) 2 , Zr(Ar) 2 , Hf(R) 2 , Hf(Ar) 2 , SO 2 or SO; Z is the same or different in each case and is N(R a ), N(Ar a ), O or S; X 1 identical or different in each case and being N or CR b with the proviso that not more than two X's in a ring 1 、X 2 、X 3 groups are N, or the X 1 group together with the X 2 group forms an ortho-fused aromatic or heteroaromatic ring system having from 5 to 60 aromatic ring atoms and which may be substituted by one or more R b groups; X 2 identical or different in each case and being N or CR b , provided that no more than two Xs in a ring 1 、X 2 、X 3 groups are N; X 3 identical or different in each case and being N or CR b , provided that no more than two X in one ring 1 , X 2 , X 3 groups are N, or the X 3 group and the X 2 group together form an ortho-fused aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms and being optionally substituted by one or more R b groups, wherein the X 2 group in any ring and no more than one X 1 or X 3 group form an aromatic or heteroaromatic ring system; R is the same or different in each case and is H, D, OH, F, Cl, Br, I, CN, NO 2 , N(Ar) 2 , N(R c ) 2 , C(=O)N(Ar) 2 , C(=O)N(R c ) 2 , C(Ar) 3 , C(R c ) 3 , Si(Ar) 3 , Si(R c ) 3 , Ge(R c ) 2 , Ge(Ar) 3 , B(Ar) 2 , B(R c ) 2 , C(=O)Ar, C(=O)R c , P(=O)(Ar) 2 , P(=O)(R c ) 2 , P(Ar) 2 , P(R c ) 2 , S(=O)Ar, S(=O)R c , S(=O) 2 Ar, S(=O) 2 R c , OSO 2 , OSO 2 R c , a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 carbon atoms or an alkenyl or alkynyl group having 2 to 40 carbon atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl or alkynyl group may in each case be substituted by one or more R c groups, wherein one or more non-adjacent CH 2 groups may be replaced by R c C=CR c , C≡C, Si(R c ) 2 , Ge(R c ) 2 , C=O, C=S, C=Se, C=NR c , -C(=O)O-, -C(=O)NR c -, NR c , P(=O)(R c ), -O-, -S-, SO or SO 2 alternatively, an aromatic or heteroaromatic ring system having from 5 to 60 aromatic ring atoms and in each case being optionally substituted by one or more R c groups, or an aryloxy or heteroaryloxy group having from 5 to 60 aromatic ring atoms and being optionally substituted by one or more R c groups, or an arylthio or heteroarylthio group having from 5 to 60 aromatic ring atoms and being optionally substituted by one or more R c groups, or a diarylamino, arylheteroarylamino, diheteroarylamino group having from 5 to 60 aromatic ring atoms and from 1 to 10 carbon atoms in the alkyl group and being optionally substituted by one or more R c groups, or an aralkyl or heteroaralkyl group having from 5 to 60 aromatic ring atoms; simultaneously, one R group may together with other groups form a ring system; c ​ Ar is the same or different in each case and is an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms and being optionally substituted by one or more R c groups; simultaneously, two Ar groups bonded to the same carbon atom, silicon atom, germanium atom, titanium atom, zirconium atom, hafnium atom may also be bridged to each other by a single bond or a bridging group selected from: B(R c ), C(R c ) 2 , Si(R c ), 2 Ge(R c ), 2 C═O, C═NR c , C═C(R c ), 2 O, S, S═O, SO 2 , N(R c ), P(R c ) and P(═O)R c ; Ar a identical or different in each case and an aromatic or heteroaromatic ring system having from 5 to 60 aromatic ring atoms and which may be substituted by one or more R a groups; R a 、R b 、R c which are the same or different in each case and are H, D, OH, F, Cl, Br, I, CN, NO 2 , N(Ar') 2 , N(R 1 ) 2 , C(=O)N(Ar') 2 , C(=O)N(R 1 ) 2 , C(Ar') 3 , C(R 1 ) 3 , Si(Ar') 3 , Si(R 1 ) 3 、Ge(Ar') 3 、Ge(R 1 ) 3 , B(Ar') 2 , B(R 1 ) 2 , C(=O)Ar', C(=O)R 1 , P(=O)(Ar') 2 , P(=O)(R 1 ) 2 , P(Ar') 2 , P(R 1 ) 2 , S(=O)Ar', S(=O)R 1 , S(=O) 2 Ar', S(=O) 2 R 1 , OSO 2 Ar', OSO 2 R 1 , a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 carbon atoms or an alkenyl or alkynyl group having 2 to 40 carbon atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 20 carbon atoms, wherein the alkyl, alkoxy, thioalkoxy, alkenyl or alkynyl group may in each case be substituted by one or more R 1 groups, and wherein one or more non-adjacent CH 2 groups may be replaced by R 1 C=CR 1 、C≡C、Si(R 1 ) 2 、Ge(R 1 ) 2 、C=O、C=S、C=Se、C=NR 1 , -C(=O)O-, -C(=O)NR 1 -, NR 1 , P(=O)(R 1 ), -O-, -S-, SO or SO 2 is replaced by, or is an aromatic or heteroaromatic ring system having from 5 to 60 aromatic ring atoms and which in each case may be substituted by one or more R 1 groups, or an aryloxy or heteroaryloxy group having from 5 to 60 aromatic ring atoms and which may be substituted by one or more R 1 groups; simultaneously, two R a , R b , R c groups may also form a ring system with each other or with other groups; Ar' is identical or different in each case and is a ring having 5 to 60 aromatic ring atoms and may be replaced by one or more R 1 Aromatic or heteroaromatic ring system substituted with a group, wherein two Ar' groups bonded to the same carbon atom, silicon atom, germanium atom, nitrogen atom, phosphorus atom or boron atom may also be bridged to each other via a single bond or a bridging group selected from: B(R 1 )、C(R 1 ) 2 、Si(R 1 ) 2 、C=O、C=NR 1 , C=C(R 1 ) 2 ,O,S,S=O,SO 2 、N(R 1 )、P(R 1 ) and P(=O)R 1 ; R 1 Same or different in each case and being H, D, F, Cl, Br, I, CN, NO 2 , N(Ar”) 2 , N(R 2 ) 2 , C(=O)Ar”, C(=O)R 2 , P(=O)(Ar”) 2 , P(Ar”) 2 , B(Ar”) 2 , B(R 2 ) 2 , C(Ar”) 3 , C(R 2 ) 3 , Si(Ar”) 3 , Si(R 2 ) 3 , a straight-chain alkyl, alkoxy or thioalkoxy group having 1 to 40 carbon atoms or a branched or cyclic alkyl, alkoxy or thioalkoxy group having 3 to 40 carbon atoms or an alkenyl group having 2 to 40 carbon atoms, each of said groups being optionally substituted by one or more R 2 groups, where one or more non-adjacent CH 2 groups may be replaced by -R 2 C=CR 2 -, -C≡C-, Si(R 2 ) 2 , C=O, C=S, C=Se, C=NR 2 , -C(=O)O-, -C(=O)NR 2 (-), NR 2 , P(=O)(R 2 ), -O-, -S-, SO or SO 2 and where one or more hydrogen atoms may be replaced by D, F, Cl, Br, I, CN or NO 2 , or an aromatic or heteroaromatic ring system having 5 to 60 aromatic ring atoms and being optionally substituted by one or more R 2 groups, or an aryloxy or heteroaryloxy group having 5 to 60 aromatic ring atoms and being optionally substituted by one or more R 2 groups, or an aralkyl or heteroaralkyl group having 5 to 60 aromatic ring atoms and being optionally substituted by one or more R 2 groups, or a combination of these systems; simultaneously, two or more R 1 groups together may form a ring system; simultaneously, one or more R 1 groups may form a ring system with other parts of the compound; Ar" is identical or different in each case and is a radical having 5 to 30 aromatic ring atoms and may be replaced by one or more R 2 Aromatic or heteroaromatic ring system substituted with a group, wherein two Ar" groups bonded to the same carbon atom, silicon atom, nitrogen atom, phosphorus atom or boron atom may also be bridged to each other via a single bond or a bridging group selected from: B(R 2 )、C(R 2 ) 2 、Si(R 2 ) 2 、C=O、C=NR 2 , C=C(R 2 ) 2 ,O,S,S=O,SO 2 、N(R 2 )、P(R 2 ) and P(=O)R 2 ; R 2 identical or different in each case and selected from H, D, F, CN, aliphatic hydrocarbon radical groups having 1 to 20 carbon atoms or aromatic or heteroaromatic ring systems having 5 to 30 aromatic ring atoms and in which one or more hydrogen atoms may be replaced by D, F, Cl, Br, I or CN, and said aromatic or heteroaromatic ring systems may be substituted by one or more alkyl groups each having 1 to 4 carbon atoms, where two or more substituents R 2 together may form a ring system.

2. The compound according to claim 1, the compound comprising at least one structure of formula (I-1) to (I-11), wherein the symbols Z, A and R b have the definitions given in claim 1, and X is N or C(R b ).

3. The compound according to claim 1 or 2, characterized in that Ar and / or Ar a which are the same or different in each case and are selected from phenyl, biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, naphthalene, indole, benzofuran, benzothiophene, carbazole, dibenzofuran, dibenzothiophene, indolocarbazole, indoloindole, pyridine, pyrimidine, pyrazine, pyridazine, triazine, quinoline, isoquinoline, quinazoline, quinoxaline, phenanthrene or terphenylidyne, each of said groups being optionally substituted by one or more R c or R a groups.

4. The compound according to one or more of claims 1 to 3, the compound comprising at least one structure of formula (II-1) to (II-8), where the symbols A and R b have the definitions given in claim 1, and the other symbols used are as follows: Y is the same or different in each case and is B(R a )、C(R a ) 2 、Si(R a ) 2 、Ge(R a ) 2 、C=O、C=NR a 、C=C(R a ) 2 、O、S、S=O、SO 2 、N(R a )、P(R a ) or P(=O)R a , where R a has the definition given in claim 1, or if there is a group bonded to the said structure, then Y is C(R a )-, Si(R a )-, Ge(R a )-; X a identical or different in each case and being N, CR a , or X if there is a group bonded to said structure a is C, provided that no more than three of the X a groups in any ring are N, where R a has the definition given in claim 1; n is 0, 1, 2 or 3; m is 0, 1, 2, 3 or 4.

5. The compound according to one or more of claims 1 to 4, the compound comprising at least one structure of formula (III-1) to (III-12), where the symbols A, R a and R b have the definitions given in claim 1, and the other symbols used are as follows: Y is the same or different in each case and is B(R a )、C(R a ) 2 、Si(R a ) 2 、Ge(R a ) 2 、C=O、C=NR a 、C=C(R a ) 2 、O、S、S=O、SO 2 、N(R a )、P(R a ) or P(=O)R a , j is 0, 1 or 2; n is 0, 1, 2 or 3; m is 0, 1, 2, 3 or 4; l is 0, 1, 2, 3, 4 or 5.

6. The compound according to one or more of claims 1 to 5, the compound comprising at least one structure of formula (IV-1) to (IV-48), where the symbol R a , R b and R c have the definitions given in claim 1, and the other symbols used are as follows: M is the same or different in each case and is C, Si, Ge, Ti, Zr or Hf; Y is the same or different in each case and is B(R a )、C(R a ) 2 、Si(R a ) 2 、Ge(R a ) 2 、C=O、C=NR a 、C=C(R a ) 2 、O、S、S=O、SO 2 、N(R a )、P(R a ) or P(=O)R a ; j is 0, 1 or 2; n is 0, 1, 2 or 3; m is 0, 1, 2, 3 or 4; l is 0, 1, 2, 3, 4 or 5.

7. The compound according to one or more of claims 1 to 6, characterized in that at least one R a , R b , R c groups are the same or different in each case and are selected from H, D, branched or cyclic alkyl, alkoxy or thioalkoxy groups having 3 to 20 carbon atoms or aromatic or heteroaromatic ring systems selected from groups of the formulae Ar-1 to Ar-76, or R a , R b , R c groups are the same or different in each case and are selected from H, D or aromatic or heteroaromatic ring systems selected from groups of the formulae Ar-1 to Ar-76, and / or Ar' groups are the same or different in each case and are selected from groups of the formulae Ar-1 to Ar-76: wherein R 1 has the definition given above, the dashed line represents a bond connecting to the corresponding group, and in addition: Ar 1 identical or different in each case and being a divalent aromatic or heteroaromatic ring system having from 6 to 18 aromatic ring atoms and being in each case optionally substituted by one or more R 1 groups; A is the same or different in each case and is C(R 1 ) 2 , NR 1 , O or S; p is 0 or 1, where p = 0 means that the Ar 1 group does not exist, and the corresponding aromatic or heteroaromatic group is directly bonded to the corresponding group; q is 0 or 1, where q = 0 means that no A group is bonded to this position, while the R 1 group is bonded to the corresponding carbon atom.

8. The compound according to at least one of the foregoing claims, characterized in that the compound comprises at least one electron transport group and / or electron-withdrawing group.

9. The compound according to at least one of the foregoing claims, characterized in that the compound comprises at least one hole transport group.

10. An oligomer, polymer or dendrimer, the oligomer, polymer or dendrimer containing one or more compounds according to any one of claims 1 to 9, wherein, one or more bonds of the compound are present connecting to the polymer, oligomer or dendrimer in place of a hydrogen atom or a substituent.

11. A formulation, the formulation comprising at least one compound according to one or more of claims 1 to 9 or an oligomer, polymer or dendrimer according to claim 10 and at least one other compound, wherein the other compound is selected from one or more solvents.

12. A composition, the composition comprising at least one compound according to one or more of claims 1 to 9 or an oligomer, polymer or dendrimer according to claim 10 and at least one other compound, the other compound being selected from fluorescent emitters, phosphorescent emitters, emitters exhibiting TADF, host materials, electron transport materials, electron injection materials, hole conduction materials, hole injection materials, electron blocking materials and hole blocking materials.

13. A method for preparing a compound according to one or more of claims 1 to 9, characterized in that synthesizing a basic skeleton having an aromatic amino group and introducing at least one aromatic or heteroaromatic group.

14. Use of a compound according to one or more of claims 1 to 9 or an oligomer, polymer or dendrimer according to claim 10 in an electronic device.

15. An electronic device comprising at least one compound according to one or more of claims 1 to 9 or an oligomer, polymer or dendrimer according to claim 10.

16. The electronic device according to claim 15, wherein the electronic device is an organic electroluminescent device, characterized in that a compound according to one or more of claims 1 to 9 or an oligomer, polymer or dendrimer according to claim 10 is used as a host material, an electron transport material, an electron injection material, a hole conduction material, a hole injection material, an electron blocking material, or a hole blocking material.

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