CONNECTIONS FOR ELECTRONIC DEVICES

Description

[0001] The present application relates to spirobifluorene amines having certain aromatic or heteroaromatic ring systems on the amine nitrogen atom. These compounds are suitable for use in electronic devices.

[0002] For the purposes of this application, "electronic devices" refers to so-called organic electronic devices, which contain organic semiconductor materials as functional materials. In particular, this includes OLEDs (organic electroluminescent devices). The term OLED refers to electronic devices that contain one or more layers of organic compounds and emit light when an electrical voltage is applied. The structure and general operating principle of OLEDs are known to those skilled in the art.

[0003] There is great interest in improving the performance of electronic devices, especially OLEDs. A completely satisfactory solution has not yet been found in these areas.

[0004] Emission layers and hole-transporting layers have a significant impact on the performance of electronic devices. New compounds are being sought for use in these layers, particularly hole-transporting compounds and compounds that can serve as hole-transporting matrix materials, especially for phosphorescent emitters, within an emissive layer. Compounds exhibiting a high glass transition temperature, high stability, and high hole conductivity are particularly sought. High compound stability is essential for achieving a long lifetime of the electronic device. Furthermore, compounds are being sought whose use in electronic devices improves their performance, particularly by increasing efficiency, lifetime, and operating at low voltages.

[0005] In the prior art, triarylamine compounds such as spirobifluorenamines and fluorenamines are known as hole-transporting materials and hole-transporting matrix materials for electronic devices. Such compounds are disclosed, for example, in US 2019 / 372025 A1. However, further improvements regarding the aforementioned properties are still needed.

[0006] Spirobifluorene amines of formula (I) below, characterized by the presence of certain aromatic or heteroaromatic ring systems on the amine nitrogen atom, have been found to be exceptionally well-suited for use in electronic devices. They are particularly suitable for use in OLEDs, especially as hole transport materials and as hole-transporting matrix materials, particularly for phosphorescent emitters. These compounds result in long lifetimes, high efficiency, and low operating voltages for the devices. Furthermore, the compounds preferably exhibit a high glass transition temperature, high stability, and high hole conductivity.

[0007] The subject of the present application is therefore combinations of a formula (I) wherein the amino group shown with variable bond position on the spirobifluorene in formula (I) is bonded either to Z1< or to Z2<; and wherein for the groups and indices occurring: A is equal to C or Si; ArL< is chosen in each occurrence either the same or different from aromatic ring systems with 6 to 40 aromatic ring atoms, each substituted with R2< residues, and heteroaromatic ring systems with 5 to 40 aromatic ring atoms, each substituted with R2< residues; Ar1< is chosen in each occurrence either the same or different from aromatic ring systems with 6 to 24 aromatic ring atoms, substituted with R3< residues, and heteroaromatic ring systems with 5 to 24 aromatic ring atoms, substituted with R3< residues;Ar 2< is chosen in each occurrence either the same or differently from phenyl substituted with R 5< residues, naphthyl substituted with R 5< residues, and heteroaromatic ring systems with 6 to 10 aromatic ring atoms, each substituted with R 5< residues; Ar 3< is chosen from groups of formulas (Ar 3< -1) to (Ar 3< -7) that bond to the residue of formula (I) via the bond marked with *; where Z 4< is chosen from CR 6< and N in each occurrence, and where in formulas (Ar 3< -2) to (Ar 3< -7) the group Z 4< is equal to C, which bonds to a freely drawn bond; where in formula (Ar 3< -3) X can also equal to C(R 6< ) 2, which bonds to the remainder of formula (I), in which case a group R 6< in this group X is replaced by the bond to the remainder of formula (I); and where X is chosen from O, S, NR 6< and C(R 6< ) 2; and where in formula (Ar 3< -3) one or more units Z 4< =Z 4< are chosen by a unit from the units can be replaced, where the atoms marked with # each replace the atoms Z 4<; and where in formula (Ar 3< -3) one or more units Z 4< -Z 4< are chosen by a unit from the units may be replaced, with the atoms marked with # each replacing the atoms Z 4<; Z is chosen from CR 1< and N in each occurrence, either the same or different; Z 1< and Z 2< are C if the amino group drawn with variable bond position is bonded to it, and otherwise chosen from CR 1< and N; Z 3< is chosen from CR 4< and N in each occurrence, either the same or different; R 1< is chosen the same or differently for each occurrence from H, D, F, Cl, Br, I, C(=O)R 7< , CN, Si(R 7< ) 3 , N(R 7< ) 2 , -(Ar L< ) k -N(Ar 4< ) 2 , P(=O)(R 7< ) 2 , OR 7< , S(=O)R 7< , S(=O) 2 R 7< , straight-chain alkyl or alkoxy groups with 1 to 20 C atoms, branched or cyclic alkyl or alkoxy groups with 3 to 20 C atoms, alkenyl or alkynyl groups with 2 to 20 C atoms, aromatic ring systems with 6 to 40 aromatic ring atoms, and heteroaromatic ring systems with 5 to 40 aromatic ring atoms;wherein two or more R1< , R2< , R3< , R4< , R5< or R6< may be linked together and form a ring; wherein the aforementioned alkyl, alkoxy, alkenyl and alkynyl groups and the aforementioned aromatic ring systems and heteroaromatic ring systems are each substituted with R7< residues; and wherein one or more CH2 groups in the aforementioned alkyl, alkoxy, alkenyl and alkynyl groups may be replaced by -R7< C=CR7< -, -C≡C-, Si(R7< )2 , C=O, C=NR7< , -C(=O)O-, -C(=O)NR7< -, NR7< , P(=O)(R7< ), -O-, -S-, SO or SO2;R2<, R3<, R4<, R5< and R6< are each chosen to be the same or different from H, D, F, Cl, Br, I, C(=O)R7<, CN, Si(R7<)3, N(R7<)2, P(=O)(R7<)2, OR7<, S(=O)R7<, S(=O)2R7<, straight-chain alkyl or alkoxy groups with 1 to 20 carbon atoms, branched or cyclic alkyl or alkoxy groups with 3 to 20 carbon atoms, alkenyl or alkynyl groups with 2 to 20 carbon atoms, aromatic ring systems with 6 to 40 aromatic ring atoms, and heteroaromatic ring systems with 5 to 40 aromatic Ring atoms; wherein two or more residues R 2< , R 3< , R 4< , R 5< or R 6< can be linked together and form a ring; wherein the aforementioned alkyl, alkoxy, alkenyl and alkynyl groups and the aforementioned aromatic ring systems and heteroaromatic ring systems are each substituted with residues R 7<;and wherein one or more CH2 groups in the aforementioned alkyl, alkoxy, alkenyl and alkynyl groups may be replaced by -R7< C=CR7< -, -C=C-, Si(R7< ) 2 , C=O, C=NR7< , -C(=O)O-, -C(=O)NR7< -, NR7< , P(=O)(R7< ), -O-, -S-, SO or SO2; Ar4< is, in each occurrence, either the same or different from aromatic ring systems with 6 to 40 aromatic ring atoms substituted with one or more R7< residues, and heteroaromatic ring systems with 5 to 40 aromatic ring atoms substituted with one or more R7< residues;R 7< is chosen the same or differently for each occurrence from H, D, F, Cl, Br, I, C(=O)R 8< , CN, Si(R 8< ) 3 , N(R 8< ) 2 , P(=O)(R 8< ) 2 , OR 8< , S(=O)R 8< , S(=O) 2 R 8< , straight-chain alkyl or alkoxy groups with 1 to 20 C atoms, branched or cyclic alkyl or alkoxy groups with 3 to 20 C atoms, alkenyl or alkynyl groups with 2 to 20 C atoms, aromatic ring systems with 6 to 40 aromatic ring atoms, and heteroaromatic ring systems with 5 to 40 aromatic ring atoms; wherein two or more residues R 1< , R 2< , R 3< , R 4< , R 5< or R 6< can be linked together and form a ring; wherein the aforementioned alkyl, alkoxy, alkenyl and alkynyl groups and the aforementioned aromatic ring systems and heteroaromatic ring systems are each substituted with residues R 8<;and wherein one or more CH2 groups in the aforementioned alkyl, alkoxy, alkenyl and alkynyl groups may be replaced by -R8< C=CR8< -, -C=C-, Si(R8< )2 , C=O, C=NR8< , -C(=O)O-, -C(=O)NR8< -, NR8< , P(=O)(R8< ), -O-, -S-, SO or SO2 R8< is chosen the same or differently from H, D, F, Cl, Br, I, CN, alkyl or alkoxy groups with 1 to 20 C atoms, alkenyl or alkynyl groups with 2 to 20 C atoms, aromatic ring systems with 6 to 40 aromatic ring atoms and heteroaromatic ring systems with 5 to 40 aromatic ring atoms; wherein two or more R< ∞ residues can be linked together and form a ring; and wherein the aforementioned alkyl, alkoxy, alkenyl and alkynyl groups, aromatic ring systems and heteroaromatic ring systems can be substituted with one or more residues selected from F and CN; k is equal to 0, 1, 2, 3 or 4; m is equal to 0, 1, 2, 3 or 4; n is equal to 1, 2, 3 or 4.

[0008] The units in square brackets in formulas (Ar 3< -3) and (Ar 3< -5) can be tied to the link marked with * at any of their positions.

[0009] The following definitions apply to the chemical groups used in this application. They apply unless more specific definitions are given.

[0010] For the purposes of this invention, an aryl group is understood to be either a single aromatic cycle, i.e., benzene, or a condensed aromatic polycycle, for example, naphthalene, phenanthrene, or anthracene. A condensed aromatic polycycle, as defined in this application, consists of two or more single aromatic cycles condensed together. Condensation between cycles means that the cycles share at least one edge. An aryl group, as defined in this invention, contains 6 to 40 aromatic ring atoms. Furthermore, an aryl group contains no heteroatoms as aromatic ring atoms, but only carbon atoms.

[0011] A heteroaryl group within the meaning of this invention is understood to be either a single heteroaromatic cycle, for example pyridine, pyrimidine, or thiophene, or a condensed heteroaromatic polycycle, for example quinoline or carbazole. A condensed heteroaromatic polycycle within the meaning of the present application consists of two or more condensed single aromatic or heteroaromatic cycles, wherein at least one of the aromatic and heteroaromatic cycles is a heteroaromatic cycle. Condensation between cycles means that the cycles share at least one edge. A heteroaryl group within the meaning of this invention contains 5 to 40 aromatic ring atoms, at least one of which is a heteroatom. The heteroatoms of the heteroaryl group are preferably selected from N, O, and S.

[0012] The term aryl or heteroaryl group, which may be substituted with the aforementioned residues, refers in particular to groups derived from benzene, naphthalene, anthracene, phenanthrene, pyrene, dihydropyrene, chrysene, perylene, triphenylene, fluoranthene, benzanthracene, benzphenanthrene, tetracene, pentacene, benzopyrene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, benzimidazolo[1,2-a]benzimidazole. Naphthimidazole, phenanthrimidazole, pyridimidazole, pyrazinimidazole, quinoxalinimidazole, oxazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, 1,2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine, benzopyrimidine, quinoxaline, pyrazine, phenazine,Naphthyridin, Azacarbazol, Benzocarbolin, Phenanthrolin, 1,2,3-Triazol, 1,2,4-Triazol, Benzotriazol, 1,2,3-Oxadiazol, 1,2,4-Oxadiazol, 1,2,5-Oxadiazol, 1,3,4-Oxadiazol, 1,2,3-Thiadiazol, 1,2,4-Thiadiazol, 1,2,5-Thiadiazol, 1,3,4-Thiadiazol, 1,3,5-Triazin, 1,2,4-Triazin, 1,2,3-Triazin, Tetrazol, 1,2,4,5-Tetrazin, 1,2,3,4-Tetrazin, 1,2,3,5-Tetrazin, Purin, Pteridin, Indolizin und Benzothiadiazol.,

[0013] An aromatic ring system within the meaning of this invention is a system that does not necessarily contain only aryl groups, but may additionally contain one or more non-aromatic rings fused to at least one aryl group. These non-aromatic rings contain exclusively carbon atoms as ring atoms. Examples of groups encompassed by this definition are tetrahydronaphthalene, fluorene, and spirobifluorene. Furthermore, the term aromatic ring system includes systems consisting of two or more aromatic ring systems linked to one another by single bonds, for example, biphenyl, terphenyl, 7-phenyl-2-fluorenyl, quaterphenyl, and 3,5-diphenyl-1-phenyl. An aromatic ring system within the meaning of this invention contains 6 to 40 carbon atoms and no heteroatoms in the ring system. The definition of "aromatic ring system" does not include heteroaryl groups.

[0014] A heteroaromatic ring system corresponds to the above definition of an aromatic ring system, with the difference that it must contain at least one heteroatom as a ring atom. As with aromatic ring systems, the heteroaromatic ring system need not consist exclusively of aryl and heteroaryl groups; it may additionally contain one or more non-aromatic rings fused to at least one aryl or heteroaryl group. The non-aromatic rings may consist exclusively of carbon atoms as ring atoms, or they may additionally contain one or more heteroatoms, preferably chosen from nitrogen, oxygen, and sulfur. Benzopyranyl is an example of such a heteroaromatic ring system.Furthermore, the term "heteroaromatic ring system" is understood to mean systems consisting of two or more aromatic or heteroaromatic ring systems linked to one another by single bonds, such as 4,6-diphenyl-2-triazinyl. A heteroaromatic ring system within the meaning of this invention contains 5 to 40 ring atoms selected from carbon and heteroatoms, wherein at least one of the ring atoms is a heteroatom. The heteroatoms of the heteroaromatic ring system are preferably selected from N, O, and S.

[0015] The terms "heteroaromatic ring system" and "aromatic ring system" as defined in the present application differ in that an aromatic ring system cannot contain a heteroatom as a ring atom, whereas a heteroaromatic ring system must contain at least one heteroatom as a ring atom. This heteroatom can be a ring atom of a non-aromatic heterocyclic ring or a ring atom of an aromatic heterocyclic ring.

[0016] According to the definitions above, every aryl group is encompassed by the term "aromatic ring system", and every heteroaryl group is encompassed by the term "heteroaromatic ring system".

[0017] An aromatic ring system with 6 to 40 aromatic ring atoms or a heteroaromatic ring system with 5 to 40 aromatic ring atoms includes, in particular, groups derived from the groups mentioned above under aryl groups and heteroaryl groups, as well as from biphenyl, terphenyl, quaterphenyl, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, indenofluorene, truxene, isotruxene, spirotruxene, spiroisotruxene, indenocarbazole, or combinations of these groups.

[0018] Within the scope of the present invention, the following are preferably defined as a straight-chain alkyl group with 1 to 20 carbon atoms, a branched or cyclic alkyl group with 3 to 20 carbon atoms, or an alkenyl or alkynyl group with 2 to 40 carbon atoms, in which individual hydrogen atoms or CH₂ groups may also be substituted by the groups mentioned above in the definition of the residues: methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl, cyclopentyl, neopentyl, n-hexyl, cyclohexyl, neo-hexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, Trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl, ethynyl, propynyl, butynyl, pentinyl, hexynyl or octynyl.

[0019] Unter einer Alkoxy- oder Thioalkylgruppe mit 1 bis 20 C-Atomen, in der auch einzelne H-Atome oder CH 2 -Gruppen durch die oben bei der Definition der Reste genannten Gruppen substituiert sein können, werden bevorzugt Methoxy, Trifluormethoxy, Ethoxy, n-Propoxy, i-Propoxy, n-Butoxy, i-Butoxy, s-Butoxy, t-Butoxy, n-Pentoxy, s-Pentoxy, 2-Methylbutoxy, n-Hexoxy, Cyclohexyloxy, n-Heptoxy, Cycloheptyloxy, n-Octyloxy, Cyclooctyloxy, 2-Ethylhexyloxy, Pentafluorethoxy, 2,2,2-Trifluorethoxy, Methylthio, Ethylthio, n-Propylthio, i-Propylthio, n-Butylthio, i-Butylthio, s-Butylthio, t-Butylthio, n-Pentylthio, s-Pentylthio, n-Hexylthio, Cyclohexylthio, n-Heptylthio, Cycloheptylthio, n-Octylthio, Cyclooctylthio, 2-Ethylhexylthio, Trifluormethylthio, Pentafluorethylthio, 2,2,2-Trifluorethylthio, Ethenylthio, Propenylthio, Butenylthio, Pentenylthio, Cyclopentenylthio, Hexenylthio, Cyclohexenylthio, Heptenylthio, Cycloheptenylthio, Octenylthio, Cyclooctenylthio, Ethinylthio, Propinylthio, Butinylthio,Pentinylthio, hexinylthio, heptinylthio, or octinylthio are understood.

[0020] In the context of this application, the phrase "two or more residues can form a ring" is understood to mean, among other things, that the two residues are linked to each other by a chemical bond. Furthermore, the phrase also means that if one of the two residues represents hydrogen, the second residue binds to the position to which the hydrogen atom was bonded, forming a ring.

[0021] Preferably, group A is equal to group C.

[0022] Preferred are Z 1< and Z 2< each C if the amino group drawn with variable bonding position is bonded to it, otherwise equal to CR 1< .

[0023] Preferably, Z 3< equals CR 4< .

[0024] Preferably, Z equals CR 1< .

[0025] Preferably, Z 4< equals CR 6< .

[0026] Z 1< and Z 2< are particularly preferred if the amino group shown with variable bonding position is bonded to it, and otherwise equal to CR 1< , Z is equal to CR 1< , Z 3< is equal to CR 4< , and Z 4< is equal to CR 6< .

[0027] Preferably, R 1< is chosen in each instance as the same or different from H, D, F, CN, Si(R 7< ) 3 , N(R 7< ) 2 , -[Ar L< ] k -N(Ar 4< ) 2 , straight-chain alkyl or alkoxy groups with 1 to 20 C atoms, branched or cyclic alkyl or alkoxy groups with 3 to 20 C atoms, aromatic ring systems with 6 to 40 aromatic ring atoms, and heteroaromatic ring systems with 5 to 40 aromatic ring atoms; wherein the aforementioned alkyl and alkoxy groups, the aforementioned aromatic ring systems and the aforementioned heteroaromatic ring systems are each substituted with R 7< residues; and wherein in the aforementioned alkyl or alkoxy groups one or more CH 2 groups may be replaced by -C=C-, -R 7< C=CR 7< -, Si(R 7< ) 2 , C=O, C=NR 7< , -NR 7< -, -O-, -S-, -C(=O)O- or -C(=O)NR 7< -.Particularly preferably, R1 is selected, in each instance, as the same or different from H, -[ArL]k-N(Ar4)2, straight-chain alkyl groups with 1 to 20 carbon atoms, branched or cyclic alkyl groups with 3 to 20 carbon atoms, aromatic ring systems with 6 to 40 aromatic ring atoms, and heteroaromatic ring systems with 5 to 40 aromatic ring atoms; wherein the aforementioned alkyl groups, aromatic ring systems, and heteroaromatic ring systems are each substituted with R7 substituents. Most preferably, R1 is equal to H.

[0028] Preferred groups R 1< in the combination of formula (I) are chosen from the following groups: R-1 R-2 R-3 R-4 R-5 R-6 R-7 R-8 R-9 R-10 R-11 R-12 R-13 R-14 R-15 R-16 R-17 R-18 R-19 R-20 R-21 R-22 R-23 R-24 R-25 R-26 R-27 R-28 R-29 R-30 R-31 R-32 R-33 R-34 R-35 R-36 R-37 R-38 R-39 R-40 R-41 R-42 R-43 R-44 R-45 R-46 R-47 R-48 R-49 R-50 R-51 R-52 R-53 R-54 R-55 R-56 R-57 R-58 R-59 R-60 R-61 R-62 R-63 R-64 R-65 R-66 R-67 R-68 R-69 R-70 R-71 R-72 R-73 R-74 R-75 R-76 R-77 R-78 R-79 R-80 R-81 R-82 R-83 R-84 R-85 R-86 R-87 R-88 R-89 R-90 R-91 R-92 R-93 R-94 R-95 R-96 R-97 R-98 R-99 R-100 R-101 R-102 R-103 R-104 R-105 R-106 R-107 R-108 R-109 R-110 R-111 R-112 R-113 R-114 R-115 R-116 R-117 R-118 R-119 R-120 R-121 R-122 R-123 R-124 R-125 R-126 R-127 R-128 R-129 R-130 R-131 R-132 R-133 R-134 R-135 R-136 R-137 R-138 R-139 R-140 R-141 -F -Cl R-142 R-143 R-144 -Br -I -H R-145 R-146 R-147 -CH3 -CH 2 CH 3 R-148 R-149 R-150 - CF 3 -CF 2 CF 3 R-151 R-152 R-153 -OCF 3 -SCF 3 - SF 5 R-154 R-155 R-156 -OCF 2 CF 3 -SCF 2 CF 3 R-157 R-158 R-159 R-160 R-161 R-162 -CN -SCN -OCH 2 CH 3 R-163 R-164 R-165 - OCH 3 -SCH 3 -Si(CH 3 ) 3 R-166 R-167 R-168 -Si(CH 3 ) 2 t-Bu -Si(iPr) 3 -Si(CH 3 ) 2 Ph R-169 R-170 R-171 Si-(Ph) 3 C-(Ph) 3 -D R-172 R-173 R-174 - CD 3 -CD 2 -CD 3 -C(CD 3 ) 3 R-175 R-176 R-177 -CD 2 -(CD 3 ) 2 - OCD 3 -SCD 3 R-178 R-179 R-180 -Si(CD 3 ) 3 R-181 R-182 R-183 -CD 2 (CH 3 ) 2 R-184 R-185 R-186 -CD 2 (CH 3 ) 3 -[On L< ] k -N(On 4< )2 R-187 R-188

[0029] Particularly favored are the formulas R-1, R-2, R-143, R-147, R-148, R-149, R-154.

[0030] Preferably, R 2< , R 3< , R 4< , R 5< and R 6< are selected, in each occurrence, as the same or different from H, D, F, CN, Si(R 7< ) 3 , N(R 7< ) 2 , straight-chain alkyl or alkoxy groups with 1 to 20 C atoms, branched or cyclic alkyl or alkoxy groups with 3 to 20 C atoms, aromatic ring systems with 6 to 40 aromatic ring atoms, and heteroaromatic ring systems with 5 to 40 aromatic ring atoms; wherein the aforementioned alkyl and alkoxy groups, the aforementioned aromatic ring systems and the aforementioned heteroaromatic ring systems are each substituted with R 7< residues; and wherein in the aforementioned alkyl or alkoxy groups one or more CH 2 groups may be replaced by -C=C-, -R 7< C=CR 7< -, Si(R 7< ) 2 , C=O, C=NR 7< , -NR 7< -, -O-, -S-, -C(=O)O- or -C(=O)NR 7< -.

[0031] According to a preferred embodiment, the compound comprises at least one, preferably a group R 4<, selected from aromatic ring systems with 6 to 40 aromatic ring atoms, and heteroaromatic ring systems with 5 to 40 aromatic ring atoms, each substituted with R 7< groups. Particularly preferred are phenyl, biphenyl, terphenyl, naphthyl, phenanthrenyl, fluorenyl, carbazolyl, dibenzofuranyl, and dibenzothiophenyl, each substituted with R 7< groups.

[0032] Preferably, R 7< is selected in each instance as the same or different from H, D, F, CN, Si(R 8< ) 3 , N(R 8< ) 2 , straight-chain alkyl or alkoxy groups with 1 to 20 C atoms, branched or cyclic alkyl or alkoxy groups with 3 to 20 C atoms, aromatic ring systems with 6 to 40 aromatic ring atoms, and heteroaromatic ring systems with 5 to 40 aromatic ring atoms; wherein the aforementioned alkyl and alkoxy groups, the aforementioned aromatic ring systems and the aforementioned heteroaromatic ring systems are each substituted with R 8< residues; and wherein in the aforementioned alkyl or alkoxy groups one or more CH 2 groups may be replaced by -C=C-, -R 8< C=CR 8< -, Si(R 8< ) 2 , C=O, C=NR 8< , -NR 8< -, -O-, -S-, -C(=O)O- or -C(=O)NR 8< -.

[0033] Index k is preferably chosen from 0, 1 and 2, especially preferably chosen from 0 and 1, and most especially preferably index k is equal to 0.

[0034] Ar L< is preferably selected in each occurrence as the same or different from aromatic or heteroaromatic rings with 6 aromatic ring atoms and aromatic or heteroaromatic ring systems with 10 aromatic ring atoms, particularly preferably selected from phenyl, biphenyl, naphthyl and fluorenyl, each of which is substituted with R 2< groups; most particularly preferably selected from phenyl, which is substituted with R 2< groups.

[0035] Ar L< is preferably chosen the same or different from groups of the following formulas for each occurrence: At L< -23 At L< -24 At L< -25 At L< -26 On L< -27 At L< -28 On L< -29 At L< -30 On L< -31 At L< -32 At L< -33 At L< -34 At L< -35 At L< -36 On L< -37 At L< -38 On L< -39 At L< -40 At L< -41 At L< -42 At L< -43 At L< -44 At L< -45 At L< -46 At L< -47 At L< -48 At L< -49 At L< -50 At L< -51 At L< -52 At L< -53 At L< -54 At L< -55 At L< -56 At L< -57 At L< -58 At L< -59 At L< -60 At L< -61 At L< -62 At L< -63 At L< -64 At L< -65 At L< -66 On L< -67 At L< -68 At L< -69 At L< -70 At L< -71 At L< -72 At L< -73 At L< -74 At L< -75 At L< -76 On L< -77 At L< -78 At L< -79 At L< -80 On L< -81 At L< -82 On L< -83 On L< -84 At L< -85 On L< -86 On L< -87 At L< -88 On L< -89 At L< -90 On L< -91 At L< -92 On L< -93 On L< -94 At L< -95 On L< -96 On L< -97 At L< -98 At L< -99 At L< -100 Ar L< -101 Ar L< -102 Ar L< -103 Ar L< -104 where the dashed lines represent the connections to the rest of the formula. Among the formulas mentioned above are the formulas Ar. L -23, Ar L -24, Ar L -25, Ar L -26, Ar L -37, Ar L -42, Ar L -47, Ar L -58 is particularly preferred.

[0036] Preferably, the index m is equal to 0 or 1. According to an alternative preferred embodiment, the index m is equal to 2 or 3, particularly preferably equal to 2.

[0037] Preferably, Ar 1< is selected, in each occurrence, as either the same or different aromatic or heteroaromatic ring systems with 6 aromatic ring atoms substituted with R 3< groups, as aromatic or heteroaromatic ring systems with 10 aromatic ring atoms substituted with R 3< groups, and as fluorenyl substituted with R 3< groups. Particularly preferably, Ar 1< is selected, in each occurrence, as either the same or different phenyl, naphthyl, fluorenyl, and biphenyl, each substituted with R 3< groups. Most preferably, Ar 3< is identical to phenyl substituted with R 3< groups.

[0038] The unit is preferably a unit , so that the compounds of formula (I) correspond to a preferred formula (I-sub):

[0039] The unit is particularly preferred when chosen from units of a formula , so that the compounds of formula (I) correspond to a preferred formula (I-sub-1), (I-sub-2) or (I-sub-3): Formal (I-sub-1) Formal (I-sub-2) Formel (I-sub-3).

[0040] Preferred Units are selected from the following: Naph-1 Naph-2 Naph-3 Naph-4 Naph-5 Naph-6 Naph-7 Naph-8 Naph-9 Naph-10 Naph-11 Naph-12 Naph-13 Naph-14 Naph-15 Naph-16 Naph-17 Naph-18 Naph-19 Naph-20 Naph-21 Naph-22 Naph-23 Naph-24 Naph-25 Naph-26 Naph-27 Naph-28 Naph-29 Naph-30 Naph-31 Naph-32 Naph-33 Naph-34 Naph-35 Naph-36 Naph-37 Naph-38 Naph-39 Naph-40 Naph-41 Naph-42 Naph-43 Naph-44 Naph-45 Naph-46 Naph-47 Naph-48 Naph-49 Naph-50 Naph-51 Naph-52 Naph-53 Naph-54 Naph-55 Naph-56 Naph-57 Naph-58 Naph-59 Naph-60 Naph-61 Naph-62 Naph-63 Naph-64 Naph-65 Naph-66 Naph-67 Naph-68 Naph-69 Naph-70 Naph-71 Naph-72 Naph-73 Naph-74 Naph-75 Naph-76 Naph-77 Naph-78 Naph-79 Naph-80 Naph-81 Naph-82 Naph-83 Naph-84 Naph-85 Naph-86 Naph-87 Naph-88 Naph-89 Naph-90 Naph-91 Naph-92 Naph-93 Naph-94 Naph-95 Naph-96 Naph-97 Naph-98 Naph-99 Naph-100 Naph-101 Naph-102 Naph-103 Naph-104 Naph-105 Naph-106 Naph-107 Naph-108 Naph-109 Naph-110 Naph-111 Naph-112 Naph-113 Naph-114 Naph-115 Naph-116 Naph-117 Naph-118 Naph-119 Naph-120 Naph-121 Naph-122 Naph-123 Naph-124 Naph-125 Naph-126 Naph-127 Naph-128 Naph-129 Naph-130 Naph-131 Naph-132 Naph-133 Naph-134 Naph-135 Naph-136 Naph-137 Naph-138 Naph-139 Naph-140 Naph-141 Naph-142 Naph-143 Naph-144 Naph-145 Naph-146 Naph-147 Naph-148 Naph-149 Naph-150 Naph-151 Naph-152 Naph-153 Naph-154 Naph-155 Naph-156 Naph-157 Naph-158 Naph-159 Naph-160 Naph-161 Naph-162 Naph-163 Naph-164 Naph-165 Naph-166 Naph-167 Naph-168 Naph-169 Naph-170 Naph-171 Naph-172 Naph-173 Naph-174 Naph-175 Naph-176 Naph-177 Naph-178 Naph-179 Naph-180 Naph-181 Naph-182 Naph-183 Naph-184 Naph-185 Naph-186 Naph-187 Naph-188 Naph-189 Naph-190 Naph-191 Naph-192 Naph-193 Naph-194 Naph-195 Naph-196 Naph-197

[0041] Among these groups, the groups Naph-1, Naph-12, Naph-18, Naph-23, Naph-25, Naph-26, Naph-27, Naph-41, Naph-52, Naph-56, Naph-82, Naph-87, Naph-108, Naph-109, Naph-116, Naph-122, Naph-194, Naph-195, Naph-197 are particularly preferred.

[0042] Preferably, Ar 2< is chosen in each occurrence as either the same or different from phenyl and naphthyl, each of which is substituted with R 5< groups; phenyl substituted with R 5< groups is particularly preferred. Phenyl can be ortho-phenylene, meta-phenylene, or para-phenylene, with para-phenylene being preferred.

[0043] Preferably, n is equal to 1 or 2.

[0044] The unit -[Ar 2< ] n - is particularly preferred, either as phenylene substituted with R 5< groups or as biphenylene substituted with R 5< groups. Para-phenylene units are preferred over meta- or ortho-phenylene units.

[0045] Preferably, Ar 3< is chosen from groups of formulas (Ar 3< -2), (Ar 3< -3) and (Ar 3< -4), particularly preferably groups of formulas (Ar 3< -2) and (Ar 3< -3). In these cases, Z 4< is preferably equal to CR 6<, or C, if the bonding to the rest of the formula occurs via this Z 4<.

[0046] Preferred groups Ar 3< are selected from the following groups: Ar 3< -1 Ar 3< -2 Ar 3< -3 Ar 3< -4 Ar 3< -5 Ar 3< -6 Ar 3< -7 Ar 3< -8 Ar 3< -9 Ar 3< -10 Ar 3< -11 Ar 3< -12 Ar 3< -13 Ar 3< -14 Ar 3< -15 Ar 3< -16 Ar 3< -17 Ar 3< -18 Ar 3< -19 Ar 3< -20 Ar 3< -21 Ar 3< -22 Ar 3< -23 Ar 3< -24 Ar 3< -25 Ar 3< -26 Ar 3< -27 Ar 3< -28 Ar 3< -29 Ar 3< -30 Ar 3< -31 Ar 3< -32 Ar 3< -33 Ar 3< -34 Ar 3< -35 Ar 3< -36 Ar 3< -37 Ar 3< -38 Ar 3< -39 Ar 3< -40 Ar 3< -41 Ar 3< -42 Ar 3< -43 Ar 3< -44 Ar 3< -45 Ar 3< -46 Ar 3< -47 Ar 3< -48 Ar 3< -49 Ar 3< -50 Ar 3< -51 Ar 3< -52 Ar 3< -53 Ar 3< -54 Ar 3< -55 Ar 3< -56 Ar 3< -57 Ar 3< -58 Ar 3< -59 Ar 3< -60 Ar 3< -61 Ar 3< -62 Ar 3< -63 Ar 3< -64 Ar 3< -65 Ar 3< -66 Ar 3< -67 Ar 3< -68 Ar 3< -69 Ar 3< -70 Ar 3< -71 Ar 3< -72 Ar 3< -73 Ar 3< -74 Ar 3< -75 Ar 3< -76 Ar 3< -77 Ar 3< -78 Ar 3< -79 Ar 3< -80 Ar 3< -81 Ar 3< -82 Ar 3< -83 Ar 3< -84 Ar 3< -85 Ar 3< -86 Ar 3< -87 Ar 3< -88 Ar 3< -89 Ar 3< -90 Ar 3< -91 Ar 3< -92 Ar 3< -93 Ar 3< -94 Ar 3< -95 Ar 3< -96 Ar 3< -97 Ar 3< -98 Ar 3< -99 Ar 3< -100 Ar 3< -101 Ar 3< -102 Ar 3< -103 Ar 3< -104 Ar 3< -105 Ar 3< -106 Ar 3< -107 Ar 3< -108 Ar 3< -109 Ar 3< -110 Ar 3< -111 Ar 3< -112 Ar 3< -113 Ar 3< -114 Ar 3< -115 Ar 3< -116 Ar 3< -117 Ar 3< -118 Ar 3< -119 Ar 3< -120 Ar 3< -121 Ar 3< -122 Ar 3< -123 Ar 3< -124 Ar 3< -125 Ar 3< -126 Ar 3< -127 Ar 3< -128 Ar 3< -129 Ar 3< -130 Ar 3< -131 Ar 3< -132 Ar 3< -133 Ar 3< -134 Ar 3< -135 Ar 3< -136 Ar 3< -137 Ar 3< -138 Ar 3< -139 Ar 3< -140 Ar 3< -141 Ar 3< -142 Ar 3< -143 Ar 3< -144 Ar 3< -145 Ar 3< -146 Ar 3< -147 Ar 3< -148 Ar 3< -149 Ar 3< -150 Ar 3< -151 Ar 3< -152 Ar 3< -153 Ar 3< -154 Ar 3< -155 Ar 3< -156 > Ar 3< -157 Ar 3< -158 Ar 3< -159 Ar 3< -160 Ar 3< -161 Ar 3< -162 Ar 3< -163 Ar 3< -164 Ar 3< -165 Ar 3< -166 Ar 3< -167 Ar 3< -168 Ar 3< -169 Ar 3< -170 Ar 3< -171 Ar 3< -172 Ar 3< -173 Ar 3< -174 Ar 3< -175 Ar 3< -176 Ar 3< -177 Ar 3< -178 Ar 3< -179 Ar 3< -180 Ar 3< -181 Ar 3< -182 Ar 3< -183 Ar 3< -184 Ar 3< -185 Ar 3< -186 Ar 3< -187 Ar 3< -188 Ar 3< -189 Ar 3< -190 Ar 3< -191 Ar 3< -192 Ar 3< -193 Ar 3< -194 Ar 3< -195 Ar 3< -196 Ar 3< -197 Ar 3< -198 Ar 3< -199 Ar 3< -200 Ar 3< -201 Ar 3< -202 Ar 3< -203 Ar 3< -204 Ar 3< -205 Ar 3< -206 Ar 3< -207 Ar 3< -208 Ar 3< -209 Ar 3< -210 Ar 3< -211 Ar 3< -212 Ar 3< -213 Ar 3< -214 Ar 3< -215 Ar 3< -216 Ar 3< -217 Ar 3< -218 Ar 3< -219 Ar 3< -220 Ar 3< -221 Ar 3< -222 Ar 3< -223 Ar 3< -224 Ar 3< -225 Ar 3< -226 Ar 3< -227 Ar 3< -228 Ar 3< -229 Ar 3< -230 Ar 3< -231 Ar 3< -232 Ar 3< -233 Ar 3< -234 Ar 3< -235 Ar 3< -236 Ar 3< -237 Ar 3< -238 Ar 3< -239 Ar 3< -240 Ar 3< -241 Ar 3< -242 Ar 3< -243 Ar 3< -244 Ar 3< -245 Ar 3< -246 Ar 3< -247 Ar 3< -248 Ar 3< -249 Ar 3< -250 Ar 3< -251 Ar 3< -252 Ar 3< -253 Ar 3< -254 Ar 3< -255 Ar 3< -256 Ar 3< -257 Ar 3< -258 Ar 3< -259 Ar 3< -260 Ar 3< -261 Ar 3< -262 Ar 3< -263 Ar 3< -264 Ar 3< -265 Ar 3< -266 Ar 3< -268 Ar 3< -269 Ar 3< -270

[0047] Among these, the groups Ar 3< -1, Ar 3< -2, Ar 3< -3, Ar 3< -5, Ar 3< -50, Ar 3< -56, Ar 3< -78, Ar 3< -82, Ar 3< -111, Ar 3< -114, Ar 3< -140, Ar 3< -141, Ar 3< -257, Ar 3< -262, Ar 3< -263 are particularly preferred.

[0048] Units -[Ar 2< ] n -Ar 3< are preferably chosen from the following units

[0049] Preferred embodiments of formula (I) are selected from the following formulas: (I-1) (I-2) (I-3) (I-4) (I-5) (I-6) (I-7) (I-8) (I-9) (I-10) wherein the variables appearing are defined as above, and wherein formulas (I-1) and (I-2) are preferred, formula (I-1) being particularly preferred. Preferably, the preferred embodiments of the variable groups and indices, in particular groups Z, Z, apply in the formulas. 3 , Ar L , Ar 1 , Ar 2 , Ar 3 , k, m and n. In particular, Z is preferably equal to CR. 1 .

[0050] In formulas (I-3) to (I-10), the preferred group is -[Ar L< ] k -N(Ar 4< ) 2 defined as a group of the formula

[0051] The corresponding preferred formulas for the combinations claimed in the application are: (I-3-1) (I-4-1) (I-6-1) (I-7-1) (I-8-1) (I-10-1) where the groups appearing are defined as above. Preferably, the preferred embodiments of the variable groups and indices, in particular groups Z, Z, apply in the formulas. 3 , Ar L , Ar 1 , Ar 2 , Ar 3 , k, m and n. In particular, Z is preferably equal to CR. 1 and Z 3 is equal to CR 4 .

[0052] Particularly preferred embodiments of formula (I) are selected from the following formulas: (I-A-1) (I-A-2) (I-A-3) (I-A-4) (I-A-5) (I-A-6) (I-A-7) (I-A-8) (I-A-9) (I-B-1) (I-B-2) (I-B-3) (I-B-4) (I-B-5) (I-B-6) (I-B-7) (I-B-8) (I-B-9) (I-C-1) (I-C-2) (I-C-3) (I-C-4) (I-C-5) (I-C-6) (I-C-7) (I-C-8) (I-C-9) (I-D-1) (I-D-2) (I-D-3) (I-D-4) (I-D-5) (I-D-6) (I-D-7) (I-D-8) (I-D-9) (I-E-1) (I-E-2) (I-E-3) (I-F-1) (I-F-2) (I-F-3) (I-F-4) (I-F-5) (I-F-6) (I-G-1) (I-G-2) (I-G-3) (I-G-4) (I-G-5) (I-G-6) (I-H-1) (I-H-2) (I-I-1) (I-I-2) (I-I-3) (I-J-1) (I-J-2) (I-J-3) (I-J-4) (I-J-5) (I-J-6) (I-K-1) (I-K-2) (I-K-3) (I-K-4) (I-K-5) (I-K-6) (I-L-1) (I-L-2) (I-M-1) (I-M-2) where groups M and Q are defined as follows: Gruppe M Gruppe Q and where the other variables are defined as above, and where R1 is defined as R 1 .

[0053] Preferred compounds are shown in the following table: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63

[0054] The following are preferred methods for preparing compounds according to formula (I):

[0055] According to the procedure shown in Scheme 1, a compound of formula (I) is prepared starting from a halogen-substituted spirobifluorene via a Buchwald coupling reaction with a diarylamine. X: Halogen G 1 , G 2 : aromatic or heteroaromatic group

[0056] Alternatively, according to the procedure shown in Scheme 2, a Buchwald coupling can first be carried out between a halogen-substituted fluorenone and a diarylamine, and then the spirobifluorene framework can be prepared by addition of ortho-haloylbiphenyl with organometallic compound and ring closure. X: Halogen G 1 , G 2 : aromatic or heteroaromatic group

[0057] Alternatively, compounds according to formula (I) containing a spacer group between the spirobifluorenyl group and the amino group can be prepared via the synthesis shown in Scheme 3. For this, a halogenyl-substituted fluorenone is reacted in a Suzuki coupling with a boronic acid-substituted aryl group bearing a halogenyl group. The coupling product is then reacted with diarylamine in a Buchwald reaction. Subsequently, analogous to the synthesis shown in Scheme 2, the spirobifluorene framework is prepared via the addition of ortho-haloylbiphenyl to an organometallic group and ring closure. X: Halogen G 1 , G 2 : aromatic or heteroaromatic group An_: aromatic or heteroaromatic group

[0058] Another preferred method for the preparation of compounds according to formula (I), which have a spacer group between the spirobifluorenyl group and the amino group, is shown in Scheme 4. For this purpose, a halogen-substituted spirobifluorene is reacted in a Suzuki coupling with an amine having three aromatic or heteroaromatic residues, one of which has a boronic acid group. X: Halogen G 1 , G 2 : aromatic or heteroaromatic group An_: aromatic or heteroaromatic group

[0059] Another preferred method for the preparation of compounds according to formula (I) having a spacer group between the spirobifluorenyl group and the amino group is shown in Scheme 5.

[0060] In this process, a spirobifluorene bearing a halogen group is reacted in a Suzuki coupling with a boronic acid-substituted aryl group bearing a halogen group. Subsequently, a diarylamine group is introduced in a Buchwald coupling. X: Halogen G 1 , G 2 : aromatic or heteroaromatic group An_: aromatic or heteroaromatic group

[0061] The present application relates to a process for the preparation of a compound of formula (I), characterized in that an amino group is introduced by means of an organometallic coupling reaction. Preferably, the organometallic coupling reaction is selected from a Suzuki coupling and a Buchwald coupling. More preferably, the organometallic coupling reaction takes place between a spirobifluorenyl derivative having a halogen substituent or a fluorenone derivative having a halogen substituent and the amino group.

[0062] The compounds according to the invention described above, in particular compounds substituted with reactive leaving groups such as bromine, iodine, chlorine, boronic acid, or boronic esters, can be used as monomers for the production of corresponding oligomers, dendrimers, or polymers. Suitable reactive leaving groups include, for example, bromine, iodine, chlorine, boronic acids, boronic esters, amines, alkenyl or alkynyl groups with terminal C-C double or C-C triple bonds, oxiranes, oxetanes, groups that undergo a cycloaddition, for example, a 1,3-dipolar cycloaddition, such as dienes or azides, carboxylic acid derivatives, alcohols, and silanes.

[0063] A further object of the invention is therefore oligomers, polymers, or dendrimers containing one or more compounds according to formula (I), wherein the bond(s) to the polymer, oligomer, or dendrimer can be located at any position substituted in formula (I) by R< 1< , R< 2< , R< 3< , R< 4< , R< 5< , or R< 6< ). Depending on the linkage of the compound according to formula (I), the compound is a component of a side chain of the oligomer or polymer or a component of the main chain. For the purposes of this invention, an oligomer is understood to be a compound composed of at least three monomer units. For the purposes of this invention, a polymer is understood to be a compound composed of at least ten monomer units. The polymers, oligomers, or dendrimers according to the invention can be conjugated, partially conjugated, or non-conjugated. The oligomers or polymers according to the invention can be linear, branched, or dendritic.In linearly linked structures, the units according to formula (I) can be directly linked to one another, or they can be linked via a bivalent group, for example, a substituted or unsubstituted alkylene group, a heteroatom, or a bivalent aromatic or heteroaromatic group. In branched and dendritic structures, for example, three or more units according to formula (I) can be linked via a trivalent or higher-valent group, for example, a trivalent or higher-valent aromatic or heteroaromatic group, to form a branched or dendritic oligomer or polymer.

[0064] The same preferences apply to the repeating units according to formula (I) in oligomers, dendrimers and polymers as described above for compounds according to formula (I).

[0065] To produce the oligomers or polymers, the monomers according to the invention are homopolymerized or copolymerized with further monomers. Suitable and preferred comonomers are selected from fluorenes, spirobifluorenes, paraphenylenes, carbazoles, thiophenes, dihydrophenanthrenes, cis- and trans-indenofluorenes, ketones, phenanthrenes, or even several of these units. The polymers, oligomers, and dendrimers typically contain further units, for example, emitting (fluorescent or phosphorescent) units, such as vinyltriarylamines or phosphorescent metal complexes, and / or charge transport units, in particular those based on triarylamines.

[0066] The polymers, oligomers and dendrimers according to the invention have advantageous properties, in particular long lifetimes, high efficiencies and good color coordinates.

[0067] The polymers and oligomers according to the invention are generally produced by polymerization of one or more types of monomers, at least one of which leads to repeat units of formula (I) in the polymer. Suitable polymerization reactions are known to those skilled in the art and are described in the literature. Particularly suitable and preferred polymerization reactions that lead to CC or CN linkages are the following: (A) SUZUKI polymerization; (B) YAMAMOTO polymerization; (C) STILLE polymerization; and (D) HARTWIG-BUCHWALD polymerization.

[0068] How the polymerization can be carried out according to these methods and how the polymers can then be separated from the reaction medium and purified is known to those skilled in the art and is described in detail in the literature.

[0069] For processing the compounds according to the invention from the liquid phase, for example by spin coating or by printing processes, formulations of the compounds according to the invention are required. These formulations can be, for example, solutions, dispersions, or emulsions. It may be preferred to use mixtures of two or more solvents for this purpose. Suitable and preferred solvents include, for example, toluene, anisole, o-, m- or p-xylene, methyl benzoate, mesitylene, tetralin, veratrol, THF, methyl-THF, THP, chlorobenzene, dioxane, phenoxytoluene, in particular 3-phenoxytoluene, (-)-fenchone, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, 1-methylnaphthalene, 2-methylbenzothiazole, 2-phenoxyethanol, 2-pyrrolidinone, 3-methylanisole, 4-methylanisole, 3,4-dimethylanisole, 3,5-dimethylanisole, acetophenone, alpha-terpineol, benzothiazole, butylbenzoate, cumene, cyclohexanol, cyclohexanone, cyclohexylbenzene. Decalin, dodecylbenzene, ethyl benzoate, indane, methyl benzoate, NMP,p-Cymene, phenetol, 1,4-diisopropylbenzene, dibenzyl ether, diethylene glycol butyl ether, triethylene glycol butyl 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 or mixtures of these solvents.

[0070] The invention therefore further relates to a formulation, in particular a solution, dispersion or emulsion, containing at least one compound according to formula (I) or at least one polymer, oligomer or dendrimer containing at least one unit according to formula (I) and at least one solvent, preferably an organic solvent. How such solutions can be prepared is known to those skilled in the art.

[0071] The compound according to formula (I) is suitable for use in an electronic device, in particular an organic electroluminescent device (OLED). Depending on the substitution, the compound of formula (I) can be used in different functions and layers. Its use as a hole-transporting material in a hole-transporting layer and / or as a matrix material in an emitting layer is preferred, especially in combination with a phosphorescent emitter.

[0072] A further object of the invention is therefore the use of a compound according to formula (I) in an electronic device. The electronic device is preferably selected from the group consisting of organic integrated circuits (OICs), organic field-effect transistors (OFETs), organic thin-film transistors (OTFTs), organic light-emitting transistors (OLETs), organic solar cells (OSCs), organic optical detectors, organic photoreceptors, organic field-quench devices (OFQDs), organic light-emitting electrochemical cells (OLECs), organic laser diodes (O-lasers), and particularly preferably organic electroluminescent devices (OLEDs).

[0073] The invention further relates to an electronic device comprising at least one connection according to formula (I). The electronic device is preferably selected from the devices mentioned above.

[0074] Particularly preferred is an organic electroluminescent device comprising an anode, a cathode, and at least one emitting layer, characterized in that at least one organic layer in the device contains at least one compound according to formula (I). A more preferred organic electroluminescent device comprising an anode, a cathode, and at least one emitting layer is characterized in that at least one organic layer in the device, selected from hole-transporting and emitting layers, contains at least one compound according to formula (I).

[0075] A hole-transporting layer is understood to be any layer arranged between the anode and the emitting layer, preferably a hole injection layer, a hole transport layer, and an electron blocking layer. A hole injection layer is understood to be a layer that directly adjoins the anode. A hole transport layer is understood to be a layer located between the anode and the emitting layer, but not directly adjacent to the anode, and preferably not directly adjacent to the emitting layer either. An electron blocking layer is understood to be a layer located between the anode and the emitting layer and directly adjacent to the emitting layer. An electron blocking layer preferably has a high-energy LUMO and thereby prevents electrons from escaping the emitting layer.

[0076] In addition to the cathode, anode, and emitting layer, the electronic device may contain further layers. These are selected, for example, from one or more hole injection layers, hole transport layers, hole blocking layers, electron transport layers, electron injection layers, electron blocking layers, exciton blocking layers, interlayers, charge-generation layers, and / or organic or inorganic p / n junctions. It should be noted, however, that not every one of these layers is necessarily present, and the choice of layers always depends on the compounds used and, in particular, on whether the device is a fluorescent or phosphorescent electroluminescent device.

[0077] The sequence of layers of the electronic device is preferably as follows: Anode - Hole injection layer - Hole transport layer - optional further hole transport layers - Emitting layer - optional hole blocking layer - Electron transport layer - Electron injection layer - Cathode.

[0078] It should be noted again that not all of the mentioned layers need to be present, and / or that additional layers may be present.

[0079] The organic electroluminescent device according to the invention can contain several emitting layers. Particularly preferably, these emission layers exhibit several emission maxima between 380 nm and 750 nm, resulting in overall white emission. This means that different emitting compounds are used in the emitting layers, which can fluoresce or phosphoresce and emit blue, green, yellow, orange, or red light. Three-layer systems are particularly preferred, i.e., systems with three emitting layers, wherein one of the three layers exhibits blue emission, one of the three layers exhibits green emission, and one of the three layers exhibits orange or red emission. The compounds according to the invention are preferably present in a hole-transporting layer or in the emitting layer.It should be noted that for the generation of white light, instead of several color-emitting emitter compounds, a single emitter compound which emits in a broad wavelength range may also be suitable.

[0080] It is preferred that the compound of formula (I) is used as the hole transport material. The emitting layer can be a fluorescent or a phosphorescent layer. Preferably, the emitting layer is a blue fluorescent or a green phosphorescent layer.

[0081] If the device containing the compound of formula (I) includes a phosphorescent emitting layer, it is preferred that this layer contains two or more, preferably exactly two, different matrix materials (mixed-matrix system). Preferred embodiments of mixed-matrix systems are described in more detail below.

[0082] If the compound according to formula (I) is used as a hole transport material in a hole transport layer, a hole injection layer or an electron blocking layer, the compound can be used as a pure material, i.e. in a proportion of 100%, in the hole transport layer, or it can be used in combination with one or more other compounds.

[0083] According to a preferred embodiment, a hole-transporting layer containing the compound of formula (I) additionally contains one or more further hole-transporting compounds. These further hole-transporting compounds are preferably selected from triarylamine compounds, particularly preferably from mono-triarylamine compounds. Most preferably, they are selected from the preferred embodiments of hole-transporting materials specified below. In the described preferred embodiment, the compound of formula (I) and the one or more further hole-transporting compounds are preferably each present in a proportion of at least 10%, particularly preferably each present in a proportion of at least 20%.

[0084] According to a preferred embodiment, a hole-transporting layer containing the compound of formula (I) additionally includes one or more p-dotandes. According to the present invention, the p-dotandes preferably used are organic electron-accepting compounds that can oxidize one or more of the other compounds in the mixture.

[0085] Particularly preferred as p-doping compounds are quinodimethane compounds, azaindenofluorenediones, azaphenalenes, azatriphenylenes, I₂, metal halides, preferably transition metal halides, metal oxides, preferably metal oxides containing at least one transition metal or a metal of group 3, and transition metal complexes, preferably complexes of Cu, Co, Ni, Pd, and Pt with ligands containing at least one oxygen atom as a bonding site. Transition metal oxides are also preferred as doping compounds, preferably oxides of rhenium, molybdenum, and tungsten, particularly Re₂O₇, MoO₃, WO₃, and ReOs. Complexes of bismuth in the (III) oxidation state, especially bismuth(III) complexes with electron-deficient ligands, particularly carboxylate ligands, are again preferred.

[0086] The p-doping agents are preferably distributed largely uniformly throughout the p-doped layers. This can be achieved, for example, by co-evaporation of the p-doping agent and the hole transport material matrix. The p-doping agent is preferably present in a proportion of 1 to 10% in the p-doped layer.

[0087] The following compounds are particularly preferred as p-doping agents:

[0088] According to a preferred embodiment, the device includes a hole injection layer corresponding to one of the following embodiments: a) it contains a triarylamine and a p-doped element; or b) it contains a single electron-deficient material (electron acceptor). According to a preferred embodiment of embodiment a), the triarylamine is a mono-triarylamine, in particular one of the preferred triarylamine derivatives mentioned below. According to a preferred embodiment of embodiment b), the electron-deficient material is a hexaazatriphenylene derivative as described in US 2007 / 0092755.

[0089] The compound of formula (I) can be contained in a hole injection layer, a hole transport layer, and / or an electron blocking layer of the device. If the compound is present in a hole injection layer or a hole transport layer, it is preferably p-doped, that is, it is present in the layer mixed with a p-doping compound as described above.

[0090] Preferably, the compound of formula (I) is contained in an electron-blocking layer. Preferably, in this case, it is not p-doped. Furthermore, preferably, it exists as a single compound in the layer, without the addition of any other compound.

[0091] According to an alternative preferred embodiment, the compound of formula (I) is incorporated into an emitting layer as a matrix material in combination with one or more emitting compounds, preferably phosphorescent emitting compounds. The phosphorescent emitting compounds are preferably selected from red and green phosphorescent compounds.

[0092] In this case, the proportion of matrix material in the emitting layer is between 50.0 and 99.9 vol.%, preferably between 80.0 and 99.5 vol.% and particularly preferably between 85.0 and 97.0 vol.%.

[0093] Accordingly, the proportion of the emitting compound is between 0.1 and 50.0 vol.%, preferably between 0.5 and 20.0 vol.% and particularly preferably between 3.0 and 15.0 vol.%.

[0094] An emitting layer of an organic electroluminescent device can also contain systems comprising multiple matrix materials (mixed-matrix systems) and / or multiple emitting compounds. In this case, too, the emitting compounds are generally those compounds with the smallest proportion in the system, and the matrix materials are those compounds with the largest proportion. In some cases, however, the proportion of a single matrix material in the system may be smaller than the proportion of a single emitting compound.

[0095] It is preferred that the compounds according to formula (I) are used as a component of mixed-matrix systems, preferably for phosphorescent emitters. The mixed-matrix systems preferably comprise two or three different matrix materials, particularly preferably two different matrix materials. Preferably, one of the two materials is a material with hole-transporting properties and the other material is a material with electron-transporting properties. It is further preferred if one of the materials is selected from compounds with a large energy difference between HOMO and LUMO (wide-bandgap materials). In a mixed-matrix system, the compound of formula (I) preferably represents the matrix material with hole-transporting properties.Accordingly, when the compound of formula (I) is used as a matrix material for a phosphorescent emitter in the emitting layer of an OLED, a second matrix compound is present in the emitting layer, which exhibits electron-transporting properties. The two different matrix materials can be present in a ratio of 1:50 to 1:1, preferably 1:20 to 1:1, particularly preferably 1:10 to 1:1, and most preferably 1:4 to 1:1.

[0096] However, the desired electron-transporting and hole-transporting properties of the mixed-matrix components can also be mainly or completely combined in a single mixed-matrix component, with the other mixed-matrix component(s) fulfilling other functions.

[0097] The following material classes are preferably used in the aforementioned layers of the device: Phosphorescent emitters:

[0098] The term phosphorescent emitters typically encompasses compounds in which light emission occurs through a spin-forbidden transition, for example, a transition from an excited triplet state or a state with a higher spin quantum number, such as a quintet state.

[0099] Suitable phosphorescent emitters are compounds that, upon appropriate excitation, emit light, preferably in the visible range, and also contain at least one atom with an atomic number greater than 20, preferably greater than 38 and less than 84, and particularly preferably greater than 56 and less than 80. Compounds containing copper, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, iridium, palladium, platinum, silver, gold, or europium are preferred as phosphorescent emitters, especially those containing iridium, platinum, or copper.

[0100] For the purposes of the present invention, all luminescent iridium, platinum or copper complexes are considered to be phosphorescent compounds.

[0101] In general, all phosphorescent complexes used in phosphorescent OLEDs according to the prior art and known to those skilled in the art in the field of organic electroluminescence devices are suitable for use in the devices according to the invention. Further examples of suitable phosphorescent emitters are shown in the following table: Fluorescent emitters:

[0102] Preferred fluorescent-emitting compounds are selected from the class of arylamines. For the purposes of this invention, an arylamine or aromatic amine is understood to be a compound containing three substituted or unsubstituted aromatic or heteroaromatic ring systems directly bonded to the nitrogen atom. Preferably, at least one of these aromatic or heteroaromatic ring systems is a condensed ring system, particularly preferably with at least 14 aromatic ring atoms. Preferred examples include aromatic anthracene, aromatic anthracenediamine, aromatic pyrene, aromatic pyrenediamine, aromatic chrysene, or aromatic chrysenediamine. An aromatic anthracene is understood to be a compound in which a diarylamine group is directly bonded to an anthracene group, preferably at position 9.An aromatic anthracenediamine is defined as a compound in which two diarylamine groups are directly bonded to an anthracene group, preferably at the 9,10 position. Aromatic pyrenamines, pyrenediamines, chrysenamines, and chrysenediamines are defined analogously, wherein the diarylamine groups are preferably bonded to the pyrene at the 1-position or the 1,6-position, respectively. Further preferred emitting compounds are indenofluorenamines or diamines, benzoindenofluorenamines or diamines, and dibenzoindenofluorenamines or diamines, as well as indenofluorene derivatives with fused aryl groups. Pyrene arylamines are also preferred. Benzoindenofluorene amines, benzofluorene amines, extended benzoindenofluorenes, phenoxazines, and fluorene derivatives linked to furan or thiophene units are also preferred. Matrix materials for fluorescent emitters:

[0103] Preferred matrix materials for fluorescent emitters are selected from the classes of oligoarylenes (e.g., 2,2',7,7'-tetraphenylspirobifluorene), in particular oligoarylenes containing fused aromatic groups, oligoarylene vinylenes, polypodal metal complexes, hole-conducting compounds, electron-conducting compounds, in particular ketones, phosphine oxides, and sulfoxides; atropisomers, boronic acid derivatives, or benzanthracenes. Particularly preferred matrix materials are selected from the classes of oligoarylenes containing naphthalene, anthracene, benzanthracene, and / or pyrene or atropisomers of these compounds, oligoarylene vinylenes, ketones, phosphine oxides, and sulfoxides. Particularly preferred matrix materials are selected from the classes of oligoarylenes containing anthracene, benzanthracene, benzphenanthrene and / or pyrene or atropisomers of these compounds.For the purposes of this invention, an oligoarylene shall be understood to be a compound in which at least three aryl or arylene groups are bonded to one another. Matrix materials for phosphorescent emitters:

[0104] Preferred matrix materials for phosphorescent emitters, besides the compounds of formula (I), are aromatic ketones, aromatic phosphine oxides or aromatic sulfoxides or sulfones, triarylamines, carbazole derivatives, e.g. CBP (N,N-biscarbazolylbiphenyl) or carbazole derivatives, indolocarbazole derivatives, indenocarbazole derivatives, azacarbazole derivatives, bipolar matrix materials, silanes, azaboroles or boron esters, triazine derivatives, zinc complexes, diazasilol or tetraazasilol derivatives, diazaphosphol derivatives, bridged carbazole derivatives, triphenylene derivatives, or lactams. Electron-transporting materials:

[0105] Suitable electron-transporting materials include, for example, the compounds disclosed in Y. Shirota et al., Chem. Rev. 2007, 107(4), 953-1010, or other materials such as those used in these layers according to the prior art.

[0106] Any materials used as electron transport materials in electron transport layers according to the prior art can be used as materials for the electron transport layer. In particular, suitable materials include aluminum complexes, for example Alq 3, zirconium complexes, for example Zrq 4, lithium complexes, for example Liq, benzimidazole derivatives, triazine derivatives, pyrimidine derivatives, pyridine derivatives, pyrazine derivatives, quinoxaline derivatives, quinoline derivatives, oxadiazole derivatives, aromatic ketones, lactams, boranes, diazaphosphole derivatives, and phosphine oxide derivatives.

[0107] Preferred electron transport and electron injection materials are shown in the following table: Hole transporting materials:

[0108] Other compounds that, in addition to the compounds of formula (I), are preferably used in hole-transporting layers of the OLEDs according to the invention are indenofluorenamine derivatives, amine derivatives, hexaazatriphenylene derivatives, amine derivatives with condensed aromatics, monobenzoindenofluorenamines, dibenzoindenofluorenamines, spirobifluorene amines, fluorene amines, spiro-dibenzopyran amines, dihydroacridine derivatives, spirodibenzofurans and spirodibenzothiophenes, phenanthrene diarylamines, spiro-tribenzotropolones, spirobifluorenes with meta-phenyldiamine groups, spiro-bisacridines, xanthene diarylamines, and 9,10-dihydroanthracene spiro compounds with diarylamine groups. The compounds disclosed in the table on pages 76-80 of WO 2020 / 109434 A1 are particularly preferred for this purpose.

[0109] The above-mentioned compounds selected from indenofluorenamine derivatives, amine derivatives, hexaazatriphenylene derivatives, amine derivatives with condensed aromatics, monobenzoindenofluorenamines, dibenzoindenofluorenamines, spirobifluorene amines, fluorene amines, spiro-dibenzopyran amines, dihydroacridine derivatives, spirodibenzofurans and spirodibenzothiophenes, phenanthrene diarylamines, spiro-tribenzotropolones, spirobifluorenes with meta-phenyldiamine groups, spiro-bisacridines, xanthene diarylamines, and 9,10-dihydroanthracene spiro compounds with diarylamine groups, and the compounds disclosed in the table on pages 76-80 of WO 2020 / 109434 A1, are generally suitable for use in layers with hole-transporting function. Layers with hole-transporting functions include hole injection layers, hole transport layers, electron blocking layers, and also emitting layers.When used in emissive layers, the compounds are suitable as matrix materials, in particular as matrix materials with hole-transporting properties. This applies to OLEDs of any structure, not only to OLEDs according to the definitions of the present application.

[0110] Particularly suitable for use in layers with hole-transporting function of any OLEDs, not only the OLEDs according to the definitions of the present application, are the following compounds: HT-1 HT-2 WO 2013 / 182263 WO 2013 / 120577 HT-3 HT-4 WO 2013 / 120577 WO 2013 / 120577 HT-5 HT-6 WO 2012 / 034627 WO 2013 / 120577 HT-7 HT-8 WO 2012 / 034627 WO 2019 / 115577 HT-9 HT-10 WO 2019 / 115577 WO 2012 / 034627 HT-11 HT-12 WO 2019 / 115577 WO 2019 / 115577 HT-13 HT-14 WO 2019 / 115577 WO 2013 / 120577 HT-15 HT-16 WO 2012 / 034627 WO 2014 / 072017

[0111] The compounds HT-1 to HT-16 are generally suitable for use in hole-transporting layers. Their use is not limited to specific OLEDs, such as the OLEDs described in the present application.

[0112] Compounds HT-1 to HT-16 can be produced according to the procedures disclosed in the patent applications listed in the table above. The further teaching concerning the use and production of the compounds, disclosed in the patent applications listed in the table above, is hereby explicitly incorporated and is preferably to be combined with the aforementioned teaching concerning the use of the aforementioned compounds as hole-transporting materials. Compounds HT-1 to HT-16 exhibit excellent properties when used in OLEDs, in particular excellent lifetime and efficiency.

[0113] Metals with low work function, metal alloys, or multilayer structures of different metals are preferred as cathodes for electronic devices. These include alkaline earth metals, alkali metals, main group metals, and lanthanides (e.g., Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.). Alloys of an alkali or alkaline earth metal and silver are also suitable, for example, a magnesium-silver alloy. In multilayer structures, additional metals with relatively high work functions, such as Ag or Al, can be used, typically in combinations of these metals, such as Ca / Ag, Mg / Ag, or Ba / Ag. It may also be advantageous to insert a thin interlayer of a material with a high dielectric constant between a metallic cathode and the organic semiconductor.Suitable materials for this purpose include alkali metal or alkaline earth metal fluorides, as well as the corresponding oxides or carbonates (e.g., LiF, Li₂O, BaF₂, MgO, NaF, CsF, Cs₂CO₃, etc.). Lithium quinolinate (LiQ) can also be used. The thickness of this layer is preferably between 0.5 and 5 nm.

[0114] Materials with a high work function are preferred as anodes. Preferably, the anode has a work function greater than 4.5 eV vs. vacuum. Metals with a high redox potential, such as Ag, Pt, or Au, are suitable for this purpose. Alternatively, metal / metal oxide electrodes (e.g., Al / Ni / NiO₂, Al / PtO₂) may also be preferred. For some applications, at least one of the electrodes must be transparent or semi-transparent to allow either the irradiation of the organic material (organic solar cell) or the extraction of light (OLED, O-LASER). Preferred anode materials in this case are conductive mixed metal oxides. Indium tin oxide (ITO) or indium zinc oxide (IZO) are particularly preferred. Conductive doped organic materials, especially conductive doped polymers, are also preferred.Furthermore, the anode can also consist of several layers, for example an inner layer of ITO and an outer layer of a metal oxide, preferably tungsten oxide, molybdenum oxide or vanadium oxide.

[0115] In a preferred embodiment, the electronic device is characterized in that one or more layers are coated using a sublimation process. The materials are deposited in vacuum sublimation systems at an initial pressure of less than 10⁻⁵ mbar, preferably less than 10⁻⁶ mbar. However, it is also possible for the initial pressure to be even lower, for example less than 10⁻⁷ mbar.

[0116] A preferred electronic device is characterized in that one or more layers are coated using the OVPD (Organic Vapor Phase Deposition) process or by means of carrier gas sublimation. The materials are applied at a pressure between 10⁻⁵ mbar and 1 bar. A special case of this process is the OVJP (Organic Vapor Jet Printing) process, in which the materials are applied directly through a nozzle and thus structured (e.g., BMS Arnold et al., Appl. Phys. Lett. 2008, 92, 053301).

[0117] A further preferred electronic device is characterized in that one or more layers are produced from a solution, e.g., by spin coating, or by any printing process, e.g., screen printing, flexographic printing, nozzle printing, or offset printing, but particularly preferably LITI (light-induced thermal imaging, thermal transfer printing) or inkjet printing. Soluble compounds according to formula (I) are required for this purpose. High solubility can be achieved by suitable substitution of the compounds.

[0118] It is further preferred that, for the production of an electronic device according to the invention, one or more layers of solution and one or more layers are applied by a sublimation process.

[0119] After the layers are applied, the device is structured, contacted, and finally sealed, depending on the application, to exclude damaging effects from water and air.

[0120] According to the invention, the electronic devices containing one or more compounds according to formula (I) can be used in displays, as light sources in lighting applications, and as light sources in medical and / or cosmetic applications. Beispiele A) Synthesis examples 1) Synthese N-[4-(naphthalen-1-yl)phenyl]-N-(4-{8-oxatricyclo[7.4.0.0 2,7< ]trideca-1(13),2,4,6,9,11-hexaen-6-yl}phenyl)-9,9'-spirobi[fluoren]-1-amin 1a

[0121]

[0122] 16.8 g of 4-(naphthalen-1-yl)-N-(4-{8-oxatricyclo[7.4.0.0 2,7< ]trideca-1(13),2,4,6,9,11-hexaen-6yl}phenyl)aniline (36.4 mmol) and 1-bromo-9,9'-spirobi[fluorene] (13.8 g, 34.7 mol) are dissolved in 250 mL of toluene. The solution is degassed and saturated with N₂. It is then treated with 1 g (5.1 mmol) of S-Phos and 1.6 g (1.7 mmol) of Pd₂(dba)₃, followed by 5 g of sodium tert-butoxide (52.05 mmol). The reaction mixture is heated to boiling overnight under a protective atmosphere. The mixture is then dispersed between toluene and water, the organic phase is washed three times with water, and dried and rotated over Na₂SO₄. After filtration of the crude product through silica gel with toluene, the remaining heptane / toluene residue is recrystallized. The substance is finally sublimed under high vacuum; purity is 99.9%, determined by HPLC. The yield is 7.1 g (26% of theory).

[0123] Similarly, the following connections are made: Bsp. Br-spiro Amin Produkt 1b 1c 1d 1e 1f 1g 1h 1i 1j 1k 1l 1m 1n 1o 1p 1p 2) Synthese 1-{[4-(naphthalen-1-yl)phenyl](4-{8-oxatricyclo[7.4.0.0 2,7< ]trideca-1(13),2,4,6,9,11-hexaen-6-yl}phenyl)amino}-9H-fluoren-9-one 2a

[0124]

[0125] N-[4-(naphthalen-1-yl)phenyl]-4-{8-oxatricyclo[7.4.0.0 2,7< ]trideca-1(9),2(7),3,5,10,12-hexaen-6-yl}aniline (40.3 g; 87.4 mmol), 1-bromofluoren-9-one (22.6 g, 87.4 mmol), and sodium tert-pentoxide (20.2 g, 174.7 mmol) are dissolved in 700 mL of toluene. The solution is degassed and saturated with N₂. It is then treated with tri-tert-butylphosphine (3.5 mL; 3.5 mmol, 1 M in toluene) and 1.6 g (1.7 mmol) of Pd₂(dba)₃. The reaction mixture is heated to boiling overnight under a protective atmosphere. The mixture is cooled and separated between toluene and water. The organic phase is washed three times with water and dried over Na₂SO₄ and rotated. After filtration of the crude product through silica gel with toluene, the remaining heptane / toluene residue is recrystallized. The yield is 49.2 g (80% of theory).

[0126] Similarly, the following connections are made: Bsp. Bromo-fluorenon Amin Produkt: 1-Amin-fluorenon 2b 2c 2d 2e 2f 2g 2h 2i 2j 3) Synthese N-[4-(naphthalen-1-yl)phenyl]-N-(4-{8-oxatricyclo[7.4.0.0 2,7< ]trideca-1(13),2,4,6,9,11-hexaen-6-yl}phenyl)-9,9'-spirobi[fluoren]-1-amin 1a 3a

[0127]

[0128] 25 g (105.2 mmol) of 2-bromo-1,1'-biphenyl are dissolved in 300 mL of dried THF in a heated flask. The reaction mixture is cooled to -78°C. At this temperature, 39.3 mL of a 2.5 M solution of n-BuLi in hexane (98.2 mmol) are slowly added dropwise. The mixture is stirred for 1 hour at -70°C. Subsequently, 49.2 g of 1-{[4-(naphthalen-1-yl)phenyl](4-{8-oxatricyclo[7.4.0.0 2,7< ]trideca-1(13),2,4,6,9,11-hexaen-6-yl}phenyl)amino}-9H-fluoren-9-one (70.1 mmol) are dissolved in 300 mL of THF and added dropwise at -70°C. After the addition is complete, the reaction mixture is slowly heated to room temperature, the reaction is stopped with NH₄Cl, and then concentrated using a rotary evaporator. The solid is slaked in 500 mL of toluene, and then 720 mg (3.8 mmol) of p-toluenesulfonic acid are added. The mixture is heated under reflux for 6 hours, then allowed to cool to room temperature and treated with water.The precipitated solid is vacuumed off and washed with heptane (40.10 g, 68% yield).

[0129] The remaining residue is recrystallized from heptane / toluene. The substance is then sublimed under high vacuum; purity is 99.9%, determined by HPLC. The yield is 19.2 g (48% of theory).

[0130] Similarly, the following connections are made: Bsp. Edukt: 1-Amin-fluorenon Br-Biphenyl Produkt 3b 3c 3d 3e 3f 3g 4) Synthesis of N-[4-(naphthalen-1-yl)phenyl]-N-(4-{8-oxatricyclo[7.4.0.0 2,7< ]trideca-1(13),2,4,6,9,11- hexaen-6-yl}phenyl)-4-{9,9'-spirobi[fluoren]-8-yl}aniline 4a

[0131]

[0132] 25.9 g (39 mmol) of 4-(naphthalen-1-yl)-N-(4-{8-oxatricyclo[7.4.0.0 2,7< ]trideca-1(13),2,4,6,9,11-hexaen-6-yl} phenyl)-N-[4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)phenyl]aniline and 16.6 g (42 mmol) of 8-bromo-9,9'-spirobi[fluorene] are suspended in 400 mL of dioxane and 13.7 g (90 mmol) of cesium fluoride. To this suspension, 4.0 g (5.4 mmol) of palladium dichloride bis(tricyclohexylphosphine) are added, and the reaction mixture is heated under reflux for 18 h. After cooling, the organic phase is separated, filtered through silica gel, washed three times with 80 mL of water, and then concentrated to dryness. After filtration of the crude product through silica gel with toluene, the remaining heptane / toluene residue is recrystallized and finally sublimed under high vacuum. Purity is 99.9%, determined by HPLC. The yield is 11 g (33% of theory).

[0133] Similarly, the following connections are made: Bsp. Spiro Amin Produkt 4b 4c 4d 4e 4f 5) Synthesis of 1-(4-Chloro-phenyl)-fluoren-9-one 5a

[0134]

[0135] 76 g (486 mmol) of 4-chlorophenylboronic acid, 120 g (463 mmol) of 1-bromofluorine, and 16 g (14 mmol) of Pd(Ph₃P)₄ are dissolved in 1.9 L of THF. The solution is degassed and saturated with N₂, and 463 mL of 2 M potassium carbonate solution are slowly added to this suspension. The reaction mixture is heated to boiling overnight under a protective atmosphere. The mixture is then dispersed between toluene and water, the organic phase is washed three times with water, and dried and rotated over Na₂SO₄. The residue is purified by crystallization with MeOH. Yield: 125 g (93% of theory), purity by HPLC >98%.

[0136] Similarly, the following connections are made: Bsp. 1-Br-Fluorenon Boronsäure Produkt 5b 5c 5d 5e 6)Synthese 1-(4-{[4-(naphthalen-1-yl)phenyl](4-{8-oxatricyclo[7.4.0.0 2,7< ]trideca-1(13),2,4,6,9,11-hexaen-6-yl}phenyl)amino}phenyl)-9H-fluoren-9-one 6a

[0137]

[0138] N-[4-(naphthalen-1-yl)phenyl]-4-{8-oxatricyclo[7.4.0.0 2,7< ]trideca-1(9),2(7),3,5,10,12-hexaen-6-yl}aniline (32 g, 69 mmol), 1-1-(4-chlorophenyl)-fluoren-9-one (20 g, 69 mmol), and sodium tert-butoxide (9.5 g, 138 mmol) are dissolved in 300 mL of toluene. The solution is degassed and saturated with N₂. It is then treated with tri-tert-butylphosphine (2 mL; 2 mmol, 1 M in toluene) and 0.98 g (1 mmol) of Pd₂(dba)₃. The reaction mixture is heated to boiling overnight under a protective atmosphere. The mixture is cooled and separated between toluene and water. The organic phase is washed three times with water and dried over Na₂SO₄ and rotated. After filtration of the crude product through silica gel with toluene, the remaining heptane / toluene residue is recrystallized. The yield is 43 g (87% of theory).

[0139] Similarly, the following connections are made: Bsp. Fluorenon Amin Produkt 6b 6c 6d 6f 6g 7) Synthese N-[4-(naphthalen-1-yl)phenyl]-N-(4-{8-oxatricyclo[7.4.0.0 2,7< ]trideca-1(13),2,4,6,9,11- hexaen-6-yl}phenyl)-4-{9,9'-spirobi[fluoren]-8-yl}aniline 7a

[0140]

[0141] 17 g (73 mmol) of 2-bromo-1,1'-biphenyl are dissolved in 90 mL of dried THF in a heated flask. The reaction mixture is cooled to -78°C. At this temperature, 165 mL of a 2.5 M solution of n-BuLi in hexane (66 mmol) are slowly added dropwise. The mixture is stirred for 1 hour at -70°C. Subsequently, 50 g of 1-(4-{[4-(naphthalen-1-yl)phenyl](4-{8-oxatricyclo [7.4.0.0 2,7< ]trideca-1(13),2,4,6,9,11-hexaen-6-yl}phenyl)amino}phenyl)-9H-fluoren-9-one (70.1 mmol) are dissolved in 300 mL of THF and added dropwise at -70°C. After the addition is complete, the reaction mixture is slowly heated to room temperature, the reaction is stopped with NH₄Cl, and then concentrated using a rotary evaporator. The solid is slaked in 500 mL of toluene, and then 720 mg (3.8 mmol) of the solid are removed. pToluenesulfonic acid was added. The mixture was heated under reflux for 6 hours, then allowed to cool to room temperature and treated with water. The precipitated solid was filtered off and washed with heptane (40.10 g, 66% yield).

[0142] The remaining residue is recrystallized from heptane / toluene. The substance is then sublimed under high vacuum; purity is 99.9%, determined by HPLC. The yield is 28 g (48% of theory).

[0143] Similarly, the following connections are made: Bsp. 1- Amine-fluorenon Br-Biphenyl Produkt 7b 7c 7d 7e 8) Synthese 8'-(4-chlorophenyl)-9,9'-spirobifluoren 8a

[0144]

[0145] 10.7 g (69 mmol) of 4-chlorophenylboronic acid, 27.2 g (69 mmol) of 1-bromospiro, and 5.4 g (5 mmol) of Pd(Ph3P)4 are dissolved in 600 mL of THF. The solution is degassed and saturated with N2, and 155 mL of 2 M potassium carbonate solution are slowly added to this suspension. The reaction mixture is heated to boiling overnight under a protective atmosphere. The mixture is then dispersed between toluene and water, the organic phase is washed three times with water, and dried and rotated over Na2SO4. The residue is purified by crystallization with MeOH. Yield: 25 g (85% of theory). Purity by HPLC >98%.

[0146] Similarly, the following connections are made: Bsp. Edukt 1 Edukt 2 Produkt 8b 8c 8d 8e 9) Synthese von N-((1,1'-biphenyl)-4-yl)N-(4-(2',7'-di-tert-butyl-9,9'-spirobi(fluorene)-1-yl)phenyl)-9,9-dimethylfluoren-2-amin 9a

[0147]

[0148] 10.1 g (28 mmol) of N-[4-(naphthalen-1-yl)phenyl]-4--8-oxatricyclo[7.4.0.02,7]trideca-1(9),2(7),3,5,10,12-hexaen-6-yl aniline and 14.5 g (27 mol) of 8'-(4-chlorophenyl)-9,9'--spirobifluorene are dissolved in 225 ml of toluene. The solution is degassed and saturated with N₂. It is then treated with 2.1 ml (2.1 mmol) of tri-tert-butylphosphine solution (1 M in toluene) and 0.98 g (1 mmol) of Pd₂(dba)₃, followed by 5.1 g (53 mmol) of sodium tert-butoxide. The reaction mixture is heated to boiling overnight under a protective atmosphere. The mixture is then dispersed between toluene and water, the organic phase is washed three times with water, and dried and rotated over Na₂SO₄. After filtration of the crude product through silica gel with toluene, the remaining heptane / toluene residue is recrystallized. The substance is finally sublimed under high vacuum; purity is 99.9%, determined by HPLC. The yield is 6 g (26% of theory).

[0149] Similarly, the following connections are made: Bsp. Spirofluoren Amin Produkt 9b 9c 9d 9e 9f 9g 10) Synthese von N-[4-(naphthalen-1-yl)phenyl]-N-(4-{8-oxatricyclo[7.4.0.0 2,7< ]trideca-1(13),2,4,6,9,11-hexaen-6-yl}phenyl)-4'-{9,9'-spirobi[fluoren]-8-yl}-[1,1'-biphenyl]-4- amine 10a

[0150]

[0151] 10.1 g (28 mmol) of N-[4-(naphthalen-1-yl)phenyl]-4--8-oxatricyclo[7.4.0.02,7]trideca-1(9),2(7),3,5,10,12-hexaen-6-yl-aniline and 14.5 g (29 mmol) of 1-{4'-chloro-[1,1'-biphenyl]-4-yl}-9,9'-spirobi[fluorene] are dissolved in 225 ml of toluene. The solution is degassed and saturated with N₂. It is then treated with 2.1 ml (2.1 mmol) of tri-tert-butylphosphine solution (1 M in toluene) and 0.98 g (1 mmol) of Pd₂(dba)₃, followed by the addition of 5.1 g (53 mmol) of sodium tert-butoxide. The reaction mixture is heated to boiling overnight under a protective atmosphere. The mixture is then dispersed between toluene and water, the organic phase is washed three times with water, and dried and rotated over Na₂SO₄. After filtration of the crude product through silica gel with toluene, the remaining heptane / toluene residue is recrystallized. Finally, the substance is sublimed under high vacuum; purity is 99.9%. The yield is 8 g (30% of theory).

[0152] Similarly, the following connections are made: Bsp. Spirofluoren Amin Produkt 10b 10c 10d 10e 10f 10g B) Device Examples 1) General manufacturing process for the OLEDs and characterization of the OLEDs

[0153] Glass plates coated with structured ITO (indium tin oxide) of 50 nm thickness form the substrates onto which the OLEDs are applied.

[0154] The OLEDs generally have the following layer structure: substrate / hole injection layer (HIL) / hole transport layer (HTL) / electron blocking layer (EBL) / emission layer (EML) / optional hole blocking layer (HBL) / electron transport layer (ETL) / electron injection layer (EIL), and finally a cathode. The cathode is formed by a 100 nm thick aluminum layer. The exact structure of the OLEDs can be found in the following tables. The materials used to manufacture the OLEDs are shown in the following table. Material H is an anthracene derivative, and material SEB is a spirobifluorene diamine. NDP-9 from Novaled AG, Dresden, is used as the p-doper.

[0155] All materials are thermally vapor-deposited in a vacuum chamber. The emission layer consists of at least one matrix material (host material) and an emitting dopant, which is added to the matrix material(s) by co-evaporation in a specific volume fraction. A specification such as H:SEB (95%:5%) means that material H is present in the layer at a volume fraction of 95% and SEB at a fraction of 5%. Similarly, the electron transport layer and the hole injection layer also consist of a mixture of two materials. The structures of the materials used in the OLEDs are shown in Table 3.

[0156] The OLEDs are characterized according to standard procedures. This involves determining the electroluminescence spectra, the external quantum efficiency (EQE, measured in %) as a function of luminance, calculated from current-voltage-luminance characteristic curves assuming a Lambertian emission characteristic, and the lifetime. The specification EQE @ 10 mA / cm²< denotes the external quantum efficiency achieved at 10 mA / cm²<. The specification U @ 10 mA / cm²< denotes the operating voltage at 10 mA / cm²<. The lifetime LT is defined as the time after which the luminance, when operating at a constant current density, decreases from the initial luminance to a certain percentage. A specification LT90 means that the stated lifetime corresponds to the time after which the luminance has decreased to 90% of its initial value. The specification @80 mA / cm 2< means that the relevant lifetime is measured at 80 mA / cm 2<. 2) OLEDs according to the invention containing a compound of formula (I) in the EBL of blue fluorescent OLEDs: Comparison of the inventive substitution positions 1 and 2 with the substitution positions 3 and 4

[0157] Devices as shown in the following table are manufactured: Bsp. HIL HTL EBL EML HBL ETL EIL Dicke / nm Dicke / nm Dicke / nm Dicke / nm Dicke / nm Dicke / nm Dicke / nm E1 HTM: p-dopant (5%) 10 nm HTM 180 nm HTM-1 10 nm H:SEB(3%) 20 nm HBM 10nm ETM:LiQ(50%) 30 nm LiQ 1 nm E2 HTM: p-dopant (5%) 10 nm HTM 180 nm HTM-2 10 nm H:SEB(3%) 20 nm HBM 10nm ETM:LiQ(50%) 30 nm LiQ 1 nm E-C1 HTM: p-dopant (5%) 10 nm HTM 180 nm HTM-C1 10 nm H:SEB(3%) 20 nm HBM 10nm ETM:LiQ(50%) 30 nm LiQ 1 nm E-C2 HTM: p-dopant (5%) 10 nm HTM 180 nm HTM-C2 10 nm H:SEB(3%) 20 nm HBM 10nm ETM:LiQ(50%) 30 nm LiQ 1 nm

[0158] Compounds according to the present application are used in the OLEDs E1 and E2. OLEDs E-C1 and E-C2 serve as a reference and contain compounds that are substituted with the amino group at positions 3 and 4 on the spiro, respectively.

[0159] According to measurements, the OLEDs according to the invention (substitution position on the spirobifluorene 1 or 2) show an improved lifetime compared to the OLEDs E-C1 and E-C2 with substitution position 3 or 4 of the amino group on the spirobifluorene: LT90 @ 60 mA / cm 2< (h) E1 210 E2 240 E-C1 180 E-C2 180 3) Use of the compounds according to the invention in the EBL of green phosphorescent OLEDs

[0160] The following OLEDs are manufactured: Bsp. HIL HTL EBL EML HBL ETL EIL Dicke / nm Dicke / nm Dicke / nm Dicke / nm Dicke / nm Dicke / nm Dicke / nm E-3 HTM: p-Dotand (5%) 20 nm HTM 90 nm HTM-1 20 nm TMM-1 (32%) TMM-2(60%) TEG (8%) 30 nm HBM 10nm ETM:LiQ(50%) 30 nm LiQ 1 nm E-4 HTM: p-Dotand (5%) 20 nm HTM 90 nm HTM-2 20 nm TMM-1 (32%) TMM-2(60%) TEG (8%) 30 nm HBM 10nm ETM:LiQ(50%) 30 nm LiQ 1 nm E-5 HTM: p-Dotand (5%) 20 nm HTM 90 nm HTM-3 20 nm TMM-1 (32%) TMM-2(60%) TEG (8%) 30 nm HBM 10nm ETM:LiQ(50%) 30 nm LiQ 1 nm

[0161] The compounds HTM-1 to HTM-3 according to the invention achieve good performance data with regard to lifetime (90 - 120 h LT90@80mA), operating voltage (3.5V-3.9VU@10mA) and efficiency (22.2-24.4% EQE@10mA). 4) Use of the compounds according to the invention in the HIL and HTL of blue fluorescent OLEDs

[0162] The following OLEDs are manufactured: Bsp. HIL HTL EBL EML HBL ETL EIL Dicke / nm Dicke / nm Dicke / nm Dicke / nm Dicke / nm Dicke / nm Dicke / nm E-6 HTM-1: p-Dotand (5%) 10 nm HTM-1 180 nm EBM 10 nm H:SEB(3%) 20 nm HBM 10nm ETM:LiQ(50%) 30 nm LiQ 1 nm E-7 HTM-2: p-Dotand (5%) 10 nm HTM-2 180 nm EBM 10 nm H:SEB(3%) 20 nm HBM 10nm ETM:LiQ(50%) 30 nm LiQ 1 nm

[0163] The connections according to the invention achieve good performance data, especially with regard to efficiency (8.0 - 9.0 % EQE@10mA), at an operating voltage of 4.0 - 8.0 VU@10mA. 5) Use of the compounds according to the invention in the EBL of blue fluorescent OLEDs

[0164] The following OLED is manufactured: Bsp. HIL HTL1 HTL2 EBL EML ETL EIL E-8 HTM-A: p-Dotand (5%) 20 nm HTM-A 160 nm HTM-4: p-Dotand (5%) 20nm HTM-4 10nm H-1:SEB-1(5%) 20 nm ETM-1 : LiQ(50%) 30 nm LiQ 1 nm

[0165] Good results are obtained with the HTM-4 compound according to the invention. The lifetime LT90@60mA is 210 h, the efficiency EQE@10mA is approximately 8%, and the voltage U@10mA is approximately 4 V. Tabelle 3: Strukturen der Verbindungen HTM-1 HTM-2 HTM-3 HTM-4 HTM-C1 HTM-C2 HTM EBM TMM-1 TMM-2 TEG ETM LiQ HBM H-1 ETM-1 SEB-1 HTM-A

Claims

1. Compound of a formula (I) where the amino group drawn with variable bonding position to the spiro-bifluorene in formula (I) is bonded either to Z1 or to Z2; and where the following applies to the groups and indices occurring: A is equal to C or Si; ArL is selected on each occurrence, identically or differently, from aromatic ring systems having 6 to 40 aromatic ring atoms, which are in each case substituted by radicals R2, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms, which are in each case substituted by radicals R2; Ar1 is selected on each occurrence, identically or differently, from aromatic ring systems having 6 to 24 aromatic ring atoms, which are substituted by radicals R3, and heteroaromatic ring systems having 5 to 24 aromatic ring atoms, which are substituted by radicals R3; Ar2 is selected on each occurrence, identically or differently, from phenyl, which is substituted by radicals R5, naphthyl, which is substituted by radicals R5, and heteroaromatic ring systems having 6 to 10 aromatic ring atoms, which are in each case substituted by radicals R5; Ar3 is selected from groups of the formulae (Ar3-1) to (Ar3-7), which are bonded to the remainder of the formula (I) via the bond marked with * where Z4 is selected on each occurrence, identically or differently, from CR6 and N, and where in formulae (Ar3-2) to (Ar3-7) the group Z4 that is bonded via a freely drawn bond is C; where in formula (Ar3-3) X equals C(R6)2 may also be bonded to the remainder of the formula (I), in which case a group R6 in this group X is replaced by the bond to the remainder of the formula (I); and where X is selected from O, S, NR6 and C(R6)2; and where in formula (Ar3-3) one or more units Z4=Z4 may be replaced by a unit selected from the units where the atoms marked with # in each case replace the atoms Z4; and where in formula (Ar3-3) one or more units Z4-Z4 may be replaced by a unit selected from the units where the atoms marked with # in each case replace the atoms Z4; Z is selected on each occurrence, identically or differently, from CR1 and N; Z1 and Z2 are in each case C if the amino group drawn with variable bonding position is bonded thereto and are otherwise selected from CR1 and N; Z3 is selected on each occurrence, identically or differently, from CR4 and N; R1 is selected on each occurrence, identically or differently, from H, D, F, Cl, Br, I, C(=O)R7, CN, Si(R7)3, N(R7)2, -(ArL)k-N(Ar4)2, P(=O)(R7)2, OR7, S(=O)R7, S(=O)2R7, straight-chain alkyl or alkoxy groups having 1 to 20 C atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 C atoms, alkenyl or alkynyl groups having 2 to 20 C atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; where two or more radicals R1, R2, R3, R4, R5 or R6 may be linked to one another and may form a ring; where the said alkyl, alkoxy, alkenyl and alkynyl groups and the said aromatic ring systems and heteroaromatic ring systems are in each case substituted by radicals R7; and where one or more CH2 groups in the said alkyl, alkoxy, alkenyl and alkynyl groups may be replaced by -R7C=CR7-, -C=C-, Si(R7)2, C=O, C=NR7, -C(=O)O-, -C(=O)NR7-, NR7, P(=O)(R7), -O-, -S-, SO or SO2; R2, R3, R4, R5 and R6 are in each case selected, on each occurrence identically or differently, from H, D, F, Cl, Br, I, C(=O)R7, CN, Si(R7)3, N(R7)2, P(=O)(R7)2, OR7, S(=O)R7, S(=O)2R7, straight-chain alkyl or alkoxy groups having 1 to 20 C atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 C atoms, alkenyl or alkynyl groups having 2 to 20 C atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; where two or more radicals R2, R3, R4, R5 or R6 may be linked to one another and may form a ring; where the said alkyl, alkoxy, alkenyl and alkynyl groups and the said aromatic ring systems and heteroaromatic ring systems are in each case substituted by radicals R7; and where one or more CH2 groups in the said alkyl, alkoxy, alkenyl and alkynyl groups may be replaced by -R7C=CR7-, -C=C-, Si(R7)2, C=O, C=NR7, -C(=O)O-, -C(=O)NR7-, NR7, P(=O)(R7), -O-, -S-, SO or SO2; Ar4 is selected on each occurrence, identically or differently, from aromatic ring systems having 6 to 40 aromatic ring atoms, which are substituted by one or more radicals R7, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms, which are substituted by one or more radicals R7; R7 is selected on each occurrence, identically or differently, from H, D, F, Cl, Br, I, C(=O)R8, CN, Si(R8)3, N(R8)2, P(=O)(R8)2, OR8, S(=O)R8, S(=O)2R8, straight-chain alkyl or alkoxy groups having 1 to 20 C atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 C atoms, alkenyl or alkynyl groups having 2 to 20 C atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; where two or more radicals R1, R2, R3, R4, R5 or R6 may be linked to one another and may form a ring; where the said alkyl, alkoxy, alkenyl and alkynyl groups and the said aromatic ring systems and heteroaromatic ring systems are in each case substituted by radicals R8; and where one or more CH2 groups in the said alkyl, alkoxy, alkenyl and alkynyl groups may be replaced by -R8C=CR8-, -C=C-, Si(R8)2, C=O, C=NR8, -C(=O)O-, -C(=O)NR8-, NR8, P(=O)(R8), -O-, -S-, SO or SO2; R8 is selected on each occurrence, identically or differently, from H, D, F, Cl, Br, I, CN, alkyl or alkoxy groups having 1 to 20 C atoms, alkenyl or alkynyl groups having 2 to 20 C atoms, aromatic ring systems having 6 to 40 aromatic ring atoms and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; where two or more radicals R8 may be linked to one another and may form a ring; and where the said alkyl, alkoxy, alkenyl and alkynyl groups, aromatic ring systems and heteroaromatic ring systems may be substituted by one or more radicals selected from F and CN; k is equal to 0, 1, 2, 3 or 4; m is equal to 0, 1, 2, 3 or 4; n is equal to 1, 2, 3 or 4.

2. Compound according to Claim 1, characterised in that Z1 and Z2 are in each case C if the amino group drawn with variable bonding position is bonded thereto, and otherwise are equal to CR1, Z is equal to CR1, Z3 is equal to CR4 and Z4 is equal to CR6.

3. Compound according to Claim 1 or 2, characterised in that R1 is selected on each occurrence, identically or differently, from H, -[ArL]k-N(Ar4)2, straight-chain alkyl groups having 1 to 20 C atoms, branched or cyclic alkyl groups having 3 to 20 C atoms, aromatic ring systems having 6 to 40 aromatic ring atoms, and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; where the said alkyl groups, the said aromatic ring systems and the said heteroaromatic ring systems are in each case substituted by radicals R7.

4. Compound according to one or more of Claims 1 to 3, characterised in that R2, R3, R4, R5 and R6 are selected on each occurrence, identically or differently, from H, D, F, CN, Si(R7)3, N(R7)2, straight-chain alkyl or alkoxy groups having 1 to 20 C atoms, branched or cyclic alkyl or alkoxy groups having 3 to 20 C atoms, aromatic ring systems having 6 to 40 aromatic ring atoms and heteroaromatic ring systems having 5 to 40 aromatic ring atoms; where the said alkyl and alkoxy groups, the said aromatic ring systems and the said heteroaromatic ring systems are in each case substituted by radicals R7; and where one or more CH2 groups in the said alkyl or alkoxy groups may be replaced by -C=C-, -R7C=CR7-, Si(R7)2, C=O, C=NR7, -NR7-, -O-, -S-, -C(=O)O- or -C(=O)NR7-.

5. Compound according to one or more or Claims 1 to 4, characterised in that it contains at least one group R4 that is selected from aromatic ring systems having 6 to 40 aromatic ring atoms and heteroaromatic ring systems having 5 to 40 aromatic ring atoms, which are in each case substituted by radicals R7.

6. Compound according to one or more of Claims 1 to 5, characterised in that index k is equal to 0.

7. Compound according to one or more of Claims 1 to 6, characterised in that Ar1 is selected on each occurrence, identically or differently, from phenyl, naphthyl, fluorenyl and biphenyl, which are in each case substituted by radicals R3.

8. Compound according to one or more of Claims 1 to 7, characterised in that it conforms to a formula selected from the following formulae: formula (I-sub-1) formula (I-sub-2) formula (I-sub-3) where the groups and indices occurring are defined as in one or more of Claims 1 to 7.

9. Compound according to one or more of Claims 1 to 8, characterised in that it conforms to one of the following formulae: (I-1) (I-2) (I-3) (I-4) (I-5) (I-6) (I-7) (I-8) (I-9) (I-10) where the indices occurring are defined as in one or more of Claims 1 to 8.

10. Compound according to one or more of Claims 1 to 9, characterised in that Ar2 is selected on each occurrence, identically or differently, from phenyl and naphthyl, which are in each case substituted by radicals R5.

11. Compound according to one or more of Claims 1 to 10, characterised in that index n is equal to 1 or 2.

12. Compound according to one or more of Claims 1 to 11, characterised in that Ar3 is selected from groups of the formulae (Ar3-2) and (Ar3-3):

13. Compound according to one or more of Claims 1 to 12, characterised in that A is equal to C.

14. Process for the preparation of a compound according to one or more of Claims 1 to 13, characterised in that an amino group is introduced by means of an organometallic coupling reaction.

15. Oligomer, polymer or dendrimer containing one or more compounds according to one or more of Claims 1 to 13, where the bond(s) to the polymer, oligomer or dendrimer may be localised at any desired positions that are substituted by R1, R2, R3, R4, R5 or R6 in formula (I).

16. Formulation comprising at least one compound according to one or more of Claims 1 to 13 or at least one polymer, oligomer or dendrimer according to Claim 15 and at least one solvent.

17. Electronic device containing at least one compound according to one or more of Claims 1 to 13 or at least one polymer, oligomer or dendrimer according to Claim 15.

18. Electronic device according to Claim 17, characterised in that it is an organic electroluminescent device and comprises anode, cathode and at least one emitting layer, and in that the compound is present in a hole-transporting layer or in an emitting layer of the device.

19. Use of a compound according to one or more of Claims 1 to 13 in an electronic device.