Dicyanoaryl compounds for organic electroluminescent devices

Abstract

The present invention relates to dicyanoaryl compounds for use in electronic devices, in particular in organic electroluminescent devices, and to electronic devices, in particular organic electroluminescent devices, which contain these materials.

Description

[0001] Dicyanoaryl compounds for organic electroluminescent devices

[0002] The present invention relates to dicyanoaryl compounds for use in electronic devices, in particular in organic electroluminescent devices, and to electronic devices, in particular organic electroluminescent devices, containing these materials.

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

[0004] In addition to an emission layer, many electroluminescent devices comprise additional layers, such as one or more hole injection layers, hole transport layers, hole blocking layers, electron transport layers, electron injection layers, exciton blocking layers, electron blocking layers, and / or charge generation layers. These layers have a significant impact on the performance of electroluminescent devices.

[0005] In addition, electroluminescent devices that use fluorescent emitters or emitters that exhibit TADF also face similar challenges.

[0006] Among other things, the electroluminescent devices described above are described in document DE 10 2020 123014 A1. However, the compounds described in DE 10 2020 123014 A1 specifically relate to materials that exhibit emission.

[0007] In general, there is still room for improvement in these materials, for example for use as matrix materials, particularly with regard to lifetime, but also with regard to the efficiency and operating voltage of the device.

[0008] The object of the present invention is therefore to provide compounds which are suitable for use in an organic electronic device, in particular in an organic electroluminescent device, and which, when used in this device, lead to good device properties, as well as to provide the corresponding electronic device.

[0009] In particular, the object of the present invention is to provide compounds that result in a long lifetime, good efficiency, and low operating voltage. Electron-injection materials, electron-transport materials, and hole-blocking materials contribute in particular to these properties. Furthermore, the properties of the matrix materials, also referred to herein as host materials, also have a significant influence on the lifetime and efficiency of the organic electroluminescent device.

[0010] Furthermore, it is the object of the present invention to provide compounds which are characterized by a low refractive index (RI).

[0011] A further object of the present invention can be seen in providing compounds suitable for use in phosphorescent or fluorescent electroluminescent devices, in particular as matrix materials. In particular, it is an object of the present invention to provide matrix materials suitable for green or blue phosphorescent electroluminescent devices and, optionally, also for red or yellow phosphorescent electroluminescent devices.

[0012] Furthermore, the compounds should lead to devices exhibiting excellent color purity, particularly when used as host material, electron injection material, electron transport material, or hole blocking material in organic electroluminescent devices.

[0013] Another task can be seen in providing electronic devices with excellent performance as cost-effectively as possible and in consistent quality

[0014] Furthermore, the electronic devices should be able to be used or adapted for a variety of purposes. In particular, the performance of the electronic devices should be maintained over a wide temperature range.

[0015] Surprisingly, it has been found that certain compounds, described in more detail below, solve this problem, are well suited for use in electroluminescent devices, and lead to organic electroluminescent devices that exhibit very good properties, particularly with regard to lifetime, color purity, efficiency, operating voltage, and refractive index. These compounds, as well as electronic devices, in particular organic electroluminescent devices, containing such compounds, are therefore the subject of the present invention.

[0016] The present invention relates to a compound according to formula (I),

[0017] where the ring Ar z represents an aromatic ring system having 6 to 60 aromatic ring atoms, preferably 6 to 30 and particularly preferably 6 to 24 ring atoms, which is substituted with one or more radicals R zmay be substituted, wherein the aromatic ring system may contain Si atoms or Ge atoms which are not directly linked to one another via a bond, and the aromatic ring system may comprise one or more ring elements with one or two O atoms and 6 ring atoms, wherein an O atom is not directly linked to an O atom, Si atom or Ge atom via a bond; the index I represents an integer in the range from 1 to 10 and Ar CN a group of the following formula (Ar c )

[0018] Formula (Ar c ), where X is CR or N, preferably CR, where at most 2 non-adjacent symbols X are N, and the dashed bond is the attachment point of the group Ar CN to the Ring Ar z means; where for the other symbols

[0019] R z represents, identically or differently at each occurrence, H, D, F, CN, C(Ar')3, C(R 1 )3, Si(Ar')3, Si(R1 )3, Ge(Ar')3, Ge(R 1 )3, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, each of which is substituted by one or more radicals R 1 may be substituted, with one or more non-adjacent CH2 groups being replaced by -R 1 C=CR 1 -, Si(R 1 )2 or Ge(R 1 )2, and wherein one or more Fl atoms may be replaced by D, F or CN, or an aromatic ring system with 6 to 24 aromatic ring atoms, each of which is replaced by one or more radicals R 1 may be substituted, preferably H, D, a straight-chain alkyl group having 1 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms or a phenyl group, each substituted with one or more radicals R 1 can be substituted, two, preferably adjacent substituents R zform a ring system, where, if two substituents R z together form a ring system, this can comprise several ring elements with 6 ring atoms containing an O;

[0020] R represents, identically or differently at each occurrence, H, D, F, C(Ar')3, C(R 1 )3, Si(Ar')3, Si(R 1 )3, Ge(Ar')3, Ge(R 1 )s, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, each of which is substituted by one or more radicals R 1 may be substituted, with one or more non-adjacent CH2 groups being replaced by -R 1 C=CR 1 -, Si(R 1 )2 Ge(R 1 )2 and where one or more H atoms can be replaced by D or F, or an aromatic ring system with 6 to 24 aromatic ring atoms, each of which is replaced by one or more radicals R 1may be substituted, preferably H, D, a straight-chain alkyl group having 1 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms or a phenyl or biphenyl group, each substituted by one or more radicals R 1 can be substituted, two, preferably adjacent, substituents R can form a ring system with each other;

[0021] Ar' is at each occurrence, identically or differently, an aromatic ring system with 6 to 60 aromatic ring atoms, which is substituted with one or more radicals R 1 may be substituted, whereby two radicals Ar' which bind to the same C-atom, Si-atom or Ge-atom may also be connected by a single bond or a bridge selected from C(R 1 )2, Si(R 1 )2 and Ge(R 1 )2, be bridged together;

[0022] R 1 is the same or different at each occurrence: H, D, F, CN, C(Ar”)3, C(R 2 )3, Si(Ar”)3, Si(R 2)3, Ge(Ar”)3, Ge(R 2 )3, a straight-chain alkyl group having 1 to 40 C atoms or a branched or cyclic alkyl group having 3 to 40 C atoms or an alkenyl group having 2 to 40 C atoms, each of which is substituted by one or more radicals R 2 may be substituted, with one or more non-adjacent CH2 groups being replaced by -R 2 C=CR 2 -, -C=C-, Si(R 2 )2 or Ge(R 2 )2 and where one or more H atoms can be replaced by D, F or CN, or an aromatic ring system with 6 to 60 aromatic ring atoms, each of which is replaced by one or more radicals R 2 may be substituted; two or more, preferably adjacent, radicals R 1 form a ring system with each other;

[0023] Ar” is at each occurrence, identically or differently, an aromatic ring system with 5 to 30 aromatic ring atoms, which with one or more radicals R 2may be substituted, whereby two radicals Ar” which bind to the same C-atom, Si-atom or Ge-atom may also be connected by a single bond or a bridge selected from C(R 2 )2, Si(R 2 )2, and Ge(R 2 ), be bridged together;

[0024] R 2 is selected, identically or differently at each occurrence, from the group consisting of H, D, F, CN, an aliphatic hydrocarbon radical having 1 to 20 C atoms or an aromatic ring system having 6 to 30 aromatic ring atoms, in which one or more H atoms may be replaced by D, F or CN and which may be substituted by one or more alkyl groups each having 1 to 4 carbon atoms, where two or more, preferably adjacent, substituents R 2 form a ring system with each other; wherein the compound according to formula (I) does not comprise an anthracene group or a fluoranthene group.

[0025] An aryl group within the meaning of this invention contains 6 to 40 carbon atoms. An aryl group is understood to be either a simple aromatic ring, i.e., benzene, or a fused (fused) aryl group, for example, naphthalene, phenanthrene, etc. Aromatics linked by a single bond, such as biphenyl, are not referred to as aryl groups, but rather as an aromatic ring system. The present compound does not comprise an anthracene or fluoranthene group. These groups are known in the art and comprise, in the case of anthracene, three linearly fused aromatic 6-membered rings or, in the case of fluoranthene, two fused aromatic 6-membered rings connected to another aromatic 6-membered ring via two bonds, thereby forming a 5-membered ring.

[0026] An aromatic ring system within the meaning of this invention contains 6 to 60 C atoms in the ring system. An aromatic ring system within the meaning of this invention is understood to mean a system that does not necessarily contain only aryl groups, but in which several aryl groups can also be linked by a non-aromatic unit, such as a C, Si, or Ge atom. For example, systems such as fluorene, 9,9'-spirobifluorene, 9,9-diarylfluorene, stilbene, etc. are also understood to be aromatic ring systems within the meaning of this invention, as are systems in which two or more aryl groups are linked, for example, by a short alkyl group. The aromatic ring system is preferably selected from fluorene, 9,9'-spirobifluorene, 9,9-diarylamine, or groups in which two or more aryl groups are linked by single bonds.Furthermore, the term aromatic ring system also includes ring systems that, in addition to one or more aryl groups, comprise one or more ring elements with one or two O atoms and 6 ring atoms. In the context of the present invention, an aliphatic hydrocarbon radical or an alkyl group which may contain 1 to 20 C atoms and in which individual H atoms or CH2 groups may be substituted by the above-mentioned groups is preferably the radicals methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, t-butyl, 2-methylbutyl, n-pentyl, s-pentyl, neo-pentyl, cyclopentyl, n-hexyl, neo-hexyl, cyclohexyl, n-heptyl, cycloheptyl, n-octyl, cyclooctyl, 2-ethylhexyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, Cyclohexenyl, heptenyl, cycloheptenyl, octenyl or cyclooctenyl.In general, alkyl groups according to the present invention may be straight-chain, branched, or cyclic, wherein one or more non-adjacent CH2 groups may be replaced by the above-mentioned groups; furthermore, one or more H atoms may be replaced by D, F, or CN, preferably F or CN.

[0027] An aromatic ring system with 6 - 60 or 6 to 40 aromatic ring atoms, which can also be substituted with the above-mentioned radicals and which can be linked to the aromatic via any position, is understood to mean in particular groups derived from benzene, naphthalene, phenanthrene, pyrene, chrysene, biphenyl, biphenylene, terphenyl, triphenylene, fluorene, spirobifluorene, dihydrophenanthrene, dihydropyrene, tetrahydropyrene, cis- or trans-indenofluorene, truxene, isotruxene, spirotruxene, spiroisotruxene or groups derived from combinations of these systems.

[0028] For the purposes of this description, the phrase "two or more residues can form a ring" is understood to mean, among other things, that the two residues are linked by a chemical bond with the formal elimination of two hydrogen atoms. This is illustrated by the following scheme. Furthermore, the above formulation should also be understood to mean that if one of the two residues represents hydrogen, the second residue binds to the position to which the hydrogen atom was bonded, forming a ring. This is illustrated by the following scheme:

[0029] In a preferred embodiment of the present invention, it can be provided that the group Ar z selected from structures of

[0030] Formulas (Ar z -1 ) to (Ar z -14) where the structures of the structures of the formulas (Ar z -1 ) to (Ar z -14) with one or more residues R z may be substituted and the other symbols have the following meaning: n, m is each independently 0 or 1 , where 0 means that the group Y is not present;

[0031] Y is C(R Z )2, Si(R z )2, Ge(R z )2, C(R Z )=C(R Z ), an ortho-linked arylene group, a bond or 0, preferably C(R Z )2,C(R Z )=C(R Z ), an ortho-linked phenylene group, a bond or 0, particularly preferably C(R Z )2, C(R Z )=C(R Z ), an ortho-linked phenylene group or a bond;

[0032] W is C, Si, Ge, preferably C or Si and particularly preferably C;

[0033] Z is C(R Z )2, Si(R z )2, Ge(R z )2, 0, preferably C(R Z )2 or Si(Rz )2, and particularly preferably C(R Z )2; and

[0034] R z has the meaning given above, in particular in formula (I).

[0035] In a further preferred embodiment, it can be provided that the group Ar z is selected from structures of the formulas (Ar z -1 a) to (Ar z -14b)

[0036]

[0037]

[0038] where the dashed bond or the dashed bonds represent the attachment site(s) of the ring Ar z to the group / groups Ar CN marked / mark and the other symbols have the following meaning: n, m is each independently 0 or 1 , where 0 means that the group Y is not present and the corresponding carbon atoms are attached to the residues R z are bound;

[0039] Y is C(R Z )2, Si(R z )2, Ge(R z )2, C(R Z )=C(R Z ), an ortho-linked arylene group, a bond or 0, preferably C(R Z )2,C(R Z )=C(R Z ), an ortho-linked phenylene group, a bond or 0, particularly preferably C(R Z )2, C(R Z )=C(R Z ), an ortho-linked phenylene group or a bond;

[0040] W is C, Si, Ge, preferably C or Si and particularly preferably C;

[0041] Z is C(R Z )2, Si(R z )2, Ge(R z )2 or 0, preferably C(R Z )2 or Si(R z )2, and particularly preferably C(R Z )2; k is 0 or 1; i is 0, 1 or 2, preferably 0 or 1; j is 0, 1, 2 or 3, preferably 0 or 1; h is 0, 1, 2, 3 or 4, preferably 0, 1 or 2, particularly preferably 0 or 1; g is 0, 1, 2, 3, 4 or 5, preferably 0, 1 or 2, particularly preferably 0 or 1; and

[0042] R z has the meaning given above, in particular in formula (I).

[0043] Preferably, the index I in formula (I) can be an integer in the range from 2 to 6, preferably 2 to 4.

[0044] Furthermore, it can be provided that the compound according to formula (I) has at least one fluorene group or one spiro group.

[0045] Preferably, the compound may correspond to one of the following formulas (II-1) to (II-34):

[0046] Formula (II-3) Formula (II-4)

[0047] Formula (11-11) Formula (11-12)

[0048] where the symbols R and R z have the meanings given above, in particular in formula (I), the indices and symbols n, m, Y, W and Z have the meanings given above, in particular in formulas (Ar z -1a) to (Ar z-14b), and furthermore: k is 0 or 1; i is 0, 1 or 2, preferably 0 or 1; j is 0, 1, 2 or 3, preferably 0 or 1; h is 0, 1, 2, 3 or 4, preferably 0, 1 or 2, particularly preferably 0 or 1; and g is 0, 1, 2, 3, 4 or 5, preferably 0, 1 or 2, particularly preferably 0 or 1.

[0049] The compounds (II-3), (II-8), (II-9), (II-12), (II-15), (II-25), (II-27), (II-29) and (II-31) are / are preferred, where in compounds of the formula (II-15) the group Y is preferably O, in compounds of the formula (II-25) at least one, preferably both of the groups Y is preferably O, in compounds of the formula (II-29) the group W is preferably C and in compounds of the formula (II-31) the group W is preferably C.

[0050] Furthermore, it can preferably be provided that in formulas (11-13) to (11-15) the group Y is selected from C(R Z )2, Si(R z )2, Ge(R z)2, C(R Z )=C(R Z ), an ortho-linked arylene group or 0, preferably C(R Z )2,C(R Z )=C(R Z ), an ortho-linked phenylene group or O, particularly preferably C(R Z )2, C(R Z )=C(R Z ) or an ortho-linked phenylene group, where R z has the meaning given above, in particular in formula (I).

[0051] Furthermore, it can preferably be provided that in formulas (II-25), (II-26) and (II-29) the sum of n + m is 1 or 2 and the group Y is selected from C(R Z )2, Si(R z )2, Ge(R z )2, C(R Z )=C(R Z ), an ortho-linked arylene group or 0, preferably C(R Z )2,C(R Z )=C(R Z ), an ortho-linked phenylene group or 0, particularly preferably C(R Z )2, C(R Z )=C(R Z ) or an ortho-linked phenylene group.

[0052] Preferably, in particular in structures of the formulas (II-1) to (II-34), it can be provided that the sum of the indices k, i, j, h and g is at most 10, preferably at most 8, particularly preferably at most 6 and particularly preferably at most 4.

[0053] Furthermore, it can be provided that at least one group R in formula (A c ) is an aromatic ring system with 6 to 24 aromatic ring atoms, each of which is substituted by one or more radicals R 1 may be substituted, but is preferably unsubstituted and / or the group in formulas (II-1) to (II-33) the index j is 1, 2 or 3 and one of the radicals R represents an aromatic ring system with 6 to 24 aromatic ring atoms, each of which is substituted by one or more radicals R 1 can be substituted, but is preferably unsubstituted.

[0054] Preferably, it can be provided that the index I in formula (I) is 1 and at least one, preferably at least two of the groups R in formula (A c ) is an aromatic ring system with 6 to 24 aromatic ring atoms, each of which is substituted by one or more radicals R 1 can be substituted, but is preferably unsubstituted.

[0055] In a further preferred embodiment, it can be provided that the group Ar CN is selected from structures of the formulas (Ar c -1 ) to (Ar c -3) and / or the group in formulas (II-1) to (II-33) is selected from structures of the formulas

[0056] (Ar c -1 ) to (Ar c -3)

[0057] Formula (Ar c -3) where the dashed bond or bonds represent the attachment point of the group Ar CN to the Ring Ar zmarked and the other symbols have the following meaning:

[0058] R a is F, H or D, preferably H or D;

[0059] R b is an aromatic ring system having 6 to 24 aromatic ring atoms, preferably 6 to 18 and particularly preferably 6 to 12 aromatic ring atoms, each of which is substituted by one or more radicals R 1 may be substituted, where R 1 has the meaning given above, in particular in formula (I), particularly preferably phenyl or biphenyl.

[0060] Preferably, the compound according to formula (I) may contain at least one group Ar CN according to formula (Ar c -3), preferably at least two groups according to formula (Ar c -3) in case the index I is at least 2.

[0061] In a further preferred embodiment, it can be provided that the compound corresponds to one of the following formulas (III-1) to (III-64):

[0062] Formula (III-1) Formula (III-2)

[0063] Formula (111-9) Formula (111-10)

[0064]

[0065] Formula (111-29) Formula (111-30)

[0066] 35

[0067] Formula (111-59) Formula (111-60)

[0068] where the symbol R z has the meaning given above, in particular for formula (I), the symbols and indices n, m, Y, W and Z have the meaning given above, in particular in formulas (Ar z -1 a) to (Ar z -14b), the symbols R a and R b which are expressed in formulas (Ar c -1 ) to (Ar c-3) and furthermore: k is 0 or 1; i is 0, 1 or 2, preferably 0 or 1; j is 0, 1, 2 or 3, preferably 0 or 1; h is 0, 1, 2, 3 or 4, preferably 0, 1 or 2, particularly preferably 0 or 1; and g is 0, 1, 2, 3, 4 or 5, preferably 0, 1 or 2, particularly preferably 0 or 1.

[0069] The compounds of the formulas (III-3), (III-11), (III-13), (III-14), (III-15), (III-16), (III-19), (III-20), (III-25), (III-26), (III-45), (III-46), (III-49), (III-50), (III-53), (III-54), (III-57) and (III-58) are / are preferred, where in compounds of the formula ((III-25) or (III-26) the group Y is preferably 0, in compounds of the formula (III-45), (III-46) at least one, preferably both of the groups Y is preferably 0, in compounds of the formula (III-53), (III-54) the group W is preferably C or Si and in compounds of the formula (III-57), (III-58) the group W is preferably C or Si.

[0070] Furthermore, it can preferably be provided that in formulas (III-23) to (III-26) the group Y is selected from C(R Z )2, Si(R z )2, Ge(R z )2, C(R Z )=C(R Z ), an ortho-linked arylene group or 0, preferably C(R Z )2,C(R Z )=C(R Z ), an ortho-linked phenylene group or O, particularly preferably C(R Z )2, C(R Z )=C(R Z ) or an ortho-linked phenylene group, where R z has the meaning given above, in particular in formula (I).

[0071] Furthermore, it can preferably be provided that in formulas (III-45) to (III-48), (III-53) and (III-53) the sum of n + m is 1 or 2 and the group Y is selected from C(R Z )2, Si(R z )2, Ge(R z )2, C(R Z )=C(R Z ), an ortho-linked arylene group or 0, preferably C(R Z )2,C(R Z )=C(RZ ), an ortho-linked phenylene group or O, particularly preferably C(R Z )2, C(R Z )=C(R Z ) or an ortho-linked phenylene group.

[0072] Preferably, in particular in structures of the formulas (III-1) to (III-64), it can be provided that the sum of the indices k, i, j, h and g is at most 10, preferably at most 8, particularly preferably at most 6 and particularly preferably at most 4.

[0073] For use in a blue-emitting electronic device, the compound may comprise a ring Ar z the formula (Ar z -12) or the formulas (Ar z -12a) to (Ar z -12e), in which the sum n + m is greater than or equal to 1, preferably 2, and wherein at least one, preferably both, of the groups Y are selected from C(R Z )2, Si(R z )2, Ge(R z )2, C(R Z )=C(R Z), an ortho-linked arylene group or 0, preferably C(R Z )2,C(R Z )=C(R Z ), an ortho-linked phenylene group or 0, particularly preferably 0. For use in a blue-emitting electronic device, it can furthermore preferably be provided that the compound has a ring Ar z the formula (Ar z -12) or the formulas (Ar z -12a) to (Ar z -12e), wherein the group W is preferably Si. Particularly preferably, the compound can have a ring Ar z the formula (Ar z -12) or the formulas (Ar z -12a) to (Ar z -12e), wherein the group W is preferably Si and wherein the sum n + m is greater than or equal to 1, preferably 2, and wherein at least one, preferably both, of the groups Y are selected from C(R Z )2, Si(R z )2, Ge(R z )2, C(R Z )=C(R Z), an ortho-linked arylene group or 0, preferably C(R Z )2,C(R Z )=C(R Z ), an ortho-linked phenylene group or 0, particularly preferably 0.

[0074] For use in a green, red or yellow emitting electronic device, the compound may comprise a ring Ar z the formula (Ar z -12) or the formulas (Ar z -12a) to (Ar z -12e), in which the sum n + m is greater than or equal to 1, preferably 2, and wherein at least one, preferably both, of the groups Y represents a bond. For use in a green, red or yellow emitting electronic device, it can be provided that the compound comprises a ring Ar z the formula (Ar z -12) or the formulas (Ar z -12a) to (Ar z - 12e), wherein the group W is preferably C. Particularly preferably, the compound can have a ring Arz the formula (Ar z -12) or the formulas (Ar z -12a) to (Ar z -12e), wherein the group W is preferably C and wherein the sum n + m is greater than or equal to 1, preferably 2, and wherein at least one, preferably both, of the groups Y represents a bond.

[0075] Furthermore, it can be provided that the compound according to the invention does not comprise a tetraphenylmethyl radical in which the four phenyl groups of the radical are not connected via a ring structure. Preferably, the compound does not comprise a tetraarylmethyl radical in which the four aryl groups of the radical are not connected via a ring structure. Accordingly, compounds with rings Ar z the formula (Ar z -12) or formulas (Ar z -12a) to (Ar z-12e) in which the sum n + m is greater than or equal to 1 are preferred over compounds in which this sum is 0. Among the particular advantages that can be achieved by this embodiment is, in particular, a longer service life of the electronic devices.

[0076] Preferably, the connection According to a preferred embodiment, the compound excluded from protection by residues R 1 be substituted.

[0077] Furthermore, in particular in compounds of the formulas (I) (II-1) to (II-34) and (III-1) to (III-64), it can be provided that at most five of the radicals R z , preferably at most two of the radicals R z and particularly preferably at most one of the radicals R z are / is not equal to H or D.

[0078] In a further embodiment, particularly in compounds of the formulas (I) (II-1) to (II-34) and (III-1) to (III-64), it can be provided that at most five of the radicals R 1 , preferably at most two of the radicals R 1 and particularly preferably at most one of the radicals R 1 are not H or D. Furthermore, it can be provided that the substituents R, R z and R 1 according to the above formulas with the ring atoms of the ring system to which the substituents R, R z and R 1 bind, do not form a condensed aromatic ring system. This excludes the formation of a condensed aromatic ring system with possible substituents R 1 and R 2 which are bound to the substituents R, R z and R 1 may be bound.

[0079] When the compound according to the invention is provided with aromatic groups R, R z , R 1 or R 2is substituted, it is preferred if these do not contain any aryl groups with more than two directly fused aromatic six-membered rings. Particularly preferably, the substituents do not contain any aryl groups with directly fused six-membered rings. This preference is due to the low triplet energy of such structures. Condensed aryl groups with more than two directly fused aromatic six-membered rings that are nevertheless also suitable according to the invention are phenanthrene and triphenylene, since these also have a high triplet level.

[0080] Preferably, it can be provided that the compound according to the invention comprises at most two, preferably at most one and particularly preferably no group with two or more condensed aromatic radicals.

[0081] When two residues, which can be selected in particular from R, R z , R 1 and / or R 2, form a ring system, this may be mono- or polycyclic, aliphatic or aromatic. The residues forming a ring system may be adjacent, ie, these residues may be attached to the same carbon atom or to carbon atoms that are directly bonded to one another, or they may be further apart. Furthermore, the residues with the substituents R, R z , R 1 and / or R 2 The ring systems may also be connected to each other via a bond, so that a ring closure can be effected. Preferably, the ring Ar z with the group Ar CN according to formula (I) or the preferred embodiments of this formula, a continuous conjugation is formed. Continuous conjugation of the aromatic systems is formed as soon as direct bonds are formed between adjacent aromatic rings.

[0082] Preferably, it can be provided that at least one radical R, R z is selected, identically or differently on each occurrence, from the group consisting of an aromatic ring system having 6 to 24 aromatic ring atoms, which is substituted with one or more radicals R 1 may be substituted, preferably at least one substituent R, R z is selected, identically or differently on each occurrence, from the group consisting of an aromatic ring system having 6 to 18 aromatic ring atoms, which is substituted with one or more radicals R 1 can be substituted.

[0083] Furthermore, it can be provided that at least one radical R, R z is selected, identically or differently at each occurrence, from phenyl, biphenyl, terphenyl, quaterphenyl, fluorenyl, spirobifluorenyl, naphthalyl, phenanthrenyl or triphenylenyl, each of which is substituted with one or more radicals R 1 can be substituted.

[0084] Furthermore, it can be provided that at least one radical R, R z is selected, identically or differently on each occurrence, from the group consisting of an aromatic ring system selected from the groups of the following formulas Ar-1 to Ar-40 and / or the group Ar' is selected, identically or differently on each occurrence, from the groups of the following formulas Ar-1 to Ar-40

[0085] Ar-11 Ar-12

[0086]

[0087] Ar-35 Ar-36 Ar-37 Ar-38

[0088] where R 1 has the meanings given above, represents the dashed bond to the corresponding group and furthermore:

[0089] Ar 1 is at each occurrence, identically or differently, a bivalent aromatic ring system with 6 to 18 aromatic ring atoms, each of which is substituted by one or more radicals R 1can be substituted;

[0090] A is the same or different at each occurrence C(R 1 )2; p is 0 or 1 , where p = 0 means that the group Ar 1 is not present and that the corresponding aromatic group is directly bonded to the corresponding residue; q is 0 or 1, where q = 0 means that no group A is bonded to this position and the corresponding carbon atoms are bonded instead to residues R 1 are bound.

[0091] Structures of the formulas (Ar-1), (Ar-2), (Ar-3), (Ar-12), (Ar-13), (Ar-14), (Ar-15), (Ar-31), (Ar-32), (Ar-33), (Ar-34), (Ar-35), (Ar-36) are preferred and structures of the formulas (Ar-1), (Ar-2), (Ar-3), (Ar-12), (Ar-13), (Ar-14), (Ar-15) are particularly preferred.

[0092] In a further preferred embodiment of the invention, the radical R, R zidentically or differently on each occurrence selected from the group consisting of H, D, F, a straight-chain alkyl group having 1 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms, where the alkyl group is in each case substituted with one or more radicals R 1 may be substituted, or an aromatic ring system having 6 to 60 aromatic ring atoms, preferably having 6 to 40 aromatic ring atoms, each substituted by one or more radicals R 1 can be substituted.

[0093] Preferred aromatic ring systems for which the substituents R, R zor Ar' or Ar" are selected from phenyl, biphenyl, in particular ortho-, meta- or para-biphenyl, terphenyl, in particular ortho-, meta-, para- or branched terphenyl, quaterphenyl, in particular ortho-, meta-, para- or branched quaterphenyl, fluorene, which may be linked via the 1-, 2-, 3- or 4-position, spirobifluorene, which may be linked via the 1-, 2-, 3- or 4-position, naphthalene, in particular 1- or -linked naphthalene, phenanthrene or triphenylene, which are each linked with one or more radicals R, R 1 or R 2may be substituted. The structures Ar-1 to Ar-40 listed above are particularly preferred, with structures of the formulas (Ar-1), (Ar-2), (Ar-3), (Ar-12), (Ar-13), (Ar-14), (Ar-15), (Ar-31), (Ar-32), (Ar-33), (Ar-34), (Ar-35), (Ar-36) being preferred and structures of the formulas (Ar-1), (Ar-2), (Ar-3), (Ar-12), (Ar-13), (Ar-14), (Ar-15). With regard to the structures Ar-1 to Ar-40, it should be noted that these can be substituted with a substituent R 1 In the case of the ring systems Ar“ these substituents R 1 by R 2 to replace.

[0094] In a further preferred embodiment of the invention, R 1 identically or differently on each occurrence selected from the group consisting of H, D, F, CN, a straight-chain alkyl group having 1 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms, where the alkyl group is in each case substituted with one or more radicals R 2may be substituted, or an aromatic ring system with 6 to 24 aromatic ring atoms, each substituted by one or more radicals R 2 may be substituted. In a particularly preferred embodiment of the invention, R 1 identically or differently on each occurrence selected from the group consisting of H, a straight-chain alkyl group having 1 to 6 C atoms, in particular having 1, 2, 3 or 4 C atoms, or a branched or cyclic alkyl group having 3 to 6 C atoms, where the alkyl group is substituted with one or more radicals R 2 may be substituted, but is preferably unsubstituted, or an aromatic ring system having 6 to 13 aromatic ring atoms, each substituted by one or more radicals R 2 can be substituted, but is preferably unsubstituted.

[0095] In a further preferred embodiment of the invention, R 2identical or different on each occurrence H, an alkyl group having 1 to 4 C atoms or an aryl group having 6 to 10 C atoms, which may be substituted by an alkyl group having 1 to 4 C atoms, but is preferably unsubstituted.

[0096] In compounds according to the invention that are processed by vacuum evaporation, the alkyl groups preferably have no more than five carbon atoms, particularly preferably no more than 4 carbon atoms, and most preferably no more than 1 carbon atom. Also suitable for compounds that are processed from solution are compounds that are substituted by alkyl groups, particularly branched alkyl groups, with up to 10 carbon atoms, or that are substituted by oligoarylene groups, for example ortho-, meta-, para-, or branched terphenyl or quaterphenyl groups.

[0097] In a preferred embodiment, the compounds according to the invention have a high degree of deuteration. Preferably, the degree of deuteration is at least 50%, preferably at least 80%, especially preferably at least 90%, and most preferably at least 95%. The degree of deuteration is determined from the numerical ratio of deuterium to the sum of deuterium and 1 H-hydrogen (D / (D+H)*100). The compounds are particularly preferably fully deuterated.

[0098] Preferably, compounds according to the invention, preferably compounds according to formulas (II-1) to (II-34) and / or (III-1) to (III-64), have a molecular weight of less than or equal to 4000 g / mol, preferably less than or equal to 3000 g / mol, particularly preferably less than or equal to 2000 g / mol, especially preferably less than or equal to 1500 g / mol, more especially preferably less than or equal to 1200 g / mol, and very particularly preferably less than or equal to 900 g / mol. Furthermore, preferred compounds according to the invention are characterized in that they are sublimable. These compounds generally have a molecular weight of less than approximately 1200 g / mol.

[0099] Furthermore, it can be provided that the compounds according to the invention, preferably compounds according to formulas (II-1) to (II-34) and / or (III-1) to (III-64), have a molecular weight of greater than or equal to 300 g / mol, preferably greater than or equal to 400 g / mol, particularly preferably greater than or equal to 500 g / mol. This improves the sublimability of the compounds.

[0100] Preferably, the compounds according to the invention, preferably compounds according to formulas (II-1) to (II-34) and / or (III-1) to (III-64), comprise at least 4, preferably 5, and particularly preferably 6 aryl radicals, which are preferably linked via a single bond. This configuration achieves particularly efficient and readily controllable sublimation of the compounds.

[0101] Preferably, the compound may not comprise a phenyl group with three or more CN residues, preferably a phenyl or naphthalyl group with three or more CN residues, and particularly preferably an aryl group with three or more CN residues. Compounds comprising one or more phenyl groups, each with three or more CN residues, exhibit lower performance than others, in particular a relatively short service life and high operating voltages of the electronic devices obtained therefrom.

[0102] The above-mentioned preferred embodiments can be combined with one another as desired within the limitations defined in claim 1. In a particularly preferred embodiment of the invention, the above-mentioned preferences occur simultaneously. Examples of preferred compounds according to the above-mentioned embodiments are the compounds listed in the following table.

[0103] The basic structure of the compounds according to the invention can be prepared according to the methods outlined in the following schemes. The individual synthesis steps, such as coupling reactions leading to CC bonds, are known in principle to the person skilled in the art. These include, among others, reactions according to SUZUKI, YAMAMOTO, NEGISHI, and HIYAMA. Further information on the synthesis of the compounds according to the invention

[0104] Compounds can be found in the synthesis examples.

[0105] The following scheme describes the preparation of the compounds of the invention by using explicit phenyl compounds reacted with an aryl compound (Ar). This representation is to be understood as an example, so that further compounds of the invention can be obtained via similar synthetic routes, for example, comprising two or more dicyanoaryl groups.

[0106] The compounds according to the invention can be prepared in one step starting from 1-halo-2,6-dicyanobenzenes and arylboronic acids or their esters in a Suzuki-type CC coupling, see Scheme 1 . Typical catalyst systems for the Suzuki coupling include literature-known combinations of palladium compounds and phosphines, such as triarylphosphines, SPhos, XPhos, RuPhos, AdaPhos, etc., typical bases include alkali metal-alkaline earth metal carbonates, phosphates, hydroxides, fluorides, and solvents for single-phase reactions include DMSO, DMF, DMAc, NMP, THF, dioxane, or for two-phase reactions, mixtures of water with THF, dioxane, glyme, alcohols, toluene, etc. Alternative coupling processes such as Negish or Grignard cross coupling can also be used.

[0107] Scheme 1

[0108] Suzuki clutch:

[0109] Alternatively, the compounds of the invention can be prepared by the process described in the literature starting from the corresponding 1,3-dicyanobenzenes under “CH activation”, see NE

[0110] Ihanainen, et al, Eur. J. Org. Chem., 2015, 3226.

[0111] Scheme (1 ) is to be understood as an example, so that other groups X are also suitable, as set out in the prior art.

[0112] The meaning of the symbols used in the scheme presented above corresponds essentially to that defined for formula (I), although for reasons of clarity, numbering and a complete representation of all symbols have been omitted.

[0113] A further object of the present invention is therefore a process for preparing a compound according to the invention, wherein a dicyanophenyl compound is synthesized and at least one aromatic radical is introduced, preferably by means of a nucleophilic aromatic substitution reaction or a coupling reaction.

[0114] By these processes, optionally followed by purification, such as recrystallization or sublimation, the compounds according to the invention can be obtained in high purity, preferably more than 99% (determined by 1 H-NMR and / or HPLC).

[0115] The compounds of the invention can also be mixed with a polymer. It is also possible to covalently incorporate these compounds into a polymer. This is particularly possible with compounds substituted by reactive leaving groups, such as bromine, iodine, chlorine, boronic acid, or boronic acid esters, or by reactive, polymerizable groups, such as olefins or oxetanes. These can be used as monomers to produce corresponding oligomers, dendrimers, or polymers. The oligomerization or polymerization preferably takes place via the halogen functionality or the boronic acid functionality, or via the polymerizable group, respectively. It is also possible to crosslink the polymers via such groups. The compounds and polymers of the invention can be used as crosslinked or uncrosslinked layers.The invention therefore further provides oligomers, polymers or dendrimers comprising one or more of the above-listed compounds of the formula (I) and preferred embodiments of these compounds, wherein, instead of a hydrogen atom or a substituent, one or more bonds of the compounds to the polymer, oligomer or dendrimer are present. Depending on the linkage of the structures of the formula (I) and preferred embodiments of this formula or of the compounds, these therefore form a side chain of the oligomer or polymer or are linked in the main chain. The polymers, oligomers or dendrimers can be conjugated, partially conjugated or non-conjugated. The oligomers or polymers can be linear, branched or dendritic. The same preferences apply to the repeating units of the compounds according to the invention in oligomers, dendrimers and polymers as described above.

[0116] To prepare the oligomers or polymers, the monomers according to the invention are homopolymerized or copolymerized with other monomers. Copolymers are preferred, wherein the units according to formula (I) or the preferred embodiments described above and below are present in amounts of 0.01 to 99.9 mol%, preferably 5 to 90 mol%, particularly preferably 20 to 80 mol%. Suitable and preferred comonomers which form the polymer backbone are selected from fluorenes (e.g. according to EP 842208 or WO 2000 / 022026), spirobifluorenes (e.g. according to EP 707020, EP 894107 or WO 2006 / 061181), para-phenylenes (e.g. according to WO 92 / 18552), carbazoles (e.g. according to WO 2004 / 070772 or WO 2004 / 113468), thiophenes (e.g. according to EP 1028136), dihydrophenanthrenes (e.g. according to WO 2005 / 014689), cis- and trans-indenofluorenes (e.g. according to WO 2004 / 041901 or WO 2004 / 113412), ketones (e.g. according to WO 2005 / 040302), phenanthrenes (e.g.according to WO 2005 / 104264 or WO 2007 / 017066) or several of these units. The polymers, oligomers and dendrimers can contain further units, for example hole transport units, in particular those based on triarylamines, and / or electron transport units. Of particular interest are also compounds according to the invention which are characterized by a high glass transition temperature. In this context, particular preference is given to compounds according to the invention comprising structures according to the formula (I) or the preferred embodiments set out above and below which have a glass transition temperature of at least 70 °C, more preferably of at least 110 °C, most preferably of at least 125 °C and especially preferably of at least 150 °C, determined according to DIN 51005 (version 2005-08).

[0117] For processing the compounds of the invention from the liquid phase, for example by spin coating or printing processes, formulations of the compounds of the invention are required. These formulations can be, for example, solutions, dispersions, or emulsions. It may be preferred to use mixtures of two or more solvents for this purpose. Suitable and preferred solvents are, for example, toluene, anisole, o-, m- or p-xylene, methyl benzoate, mesitylene, tetralin, veratrole, THF, methyl-THF, THP, chlorobenzene, dioxane, phenoxytoluene, in particular 3-phenoxytoluene, (-)-fenchone, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, 1-methylnaphthalene, 2-methylbenzothiazole, 2-phenoxyethanol, 2-pyrrolidinone, 3-methylanisole, 4-methylanisole, 3,4-dimethylanisole, 3,5-dimethylanisole, acetophenone, a-terpineol, benzothiazole, butylbenzoate, cumene, cyclohexanol, cyclohexanone, Cyclohexylbenzene, decalin, dodecylbenzene, ethyl benzoate, indane, NMP,p-Cymene, phenetole, 1,4-diisopropylbenzene, dibenzyl ether, diethylene glycol butylmethyl ether, triethylene glycol butylmethyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, tripropylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 2-isopropylnaphthalene, pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene, 1,1-bis(3,4-dimethylphenyl)ethane, 2-methylbiphenyl, 3-methylbiphenyl, 1-methylnaphthalene, 1-ethylnaphthalene, ethyl octanoate, diethyl sebacate, octyloctanoate, heptylbenzene, menthyl isovalerate, cyclohexylhexanoate or mixtures of these solvents. The present invention therefore further provides a formulation or composition comprising at least one compound according to the invention and at least one further compound. The further compound can be, for example, a solvent,in particular, one of the above-mentioned solvents or a mixture of these solvents. If the further compound comprises a solvent, this mixture is referred to herein as a formulation. However, the further compound can also be at least one further organic or inorganic compound that is also used in the electronic device, for example an emitting compound and / or a further matrix material. Preferably, it can be provided that at least one further compound is selected from the group consisting of fluorescent emitters, phosphorescent emitters, emitters that exhibit TADF, host materials, electron-transport materials, electron-injection materials, hole-conductor materials, hole-injection materials, electron-blocking materials, and hole-blocking materials, preferably host materials.

[0118] The present invention further provides for the use of a compound according to the invention in an electronic device, in particular in an organic electroluminescent device. Preferably, the compounds according to the invention are used in an electronic device as a host material, electron injection material, electron transport material, or hole blocking material, particularly preferably as an electron injection material, electron transport material, or hole blocking material.

[0119] The present invention further relates to an electronic device comprising at least one compound according to the invention. An electronic device within the meaning of the present invention is a device which contains at least one layer containing at least one organic compound. The component can also contain inorganic materials or layers composed entirely of inorganic materials. Particularly preferred is an electronic device selected from the group consisting of organic electroluminescent devices (OLEDs, sOLEDs, PLEDs, LECs, etc.), preferably organic light-emitting diodes (OLEDs), organic light-emitting diodes based on small molecules (sOLEDs), organic light-emitting diodes based on polymers (PLEDs), light-emitting electrochemical cells (LECs), organic laser diodes (O-lasers), organic plasmon emitting devices (DMKoller et al., Nature Photonics 2008, 1- 4); organic integrated circuits (O-ICs), organic field-effect transistors (O-FETs), organic thin-film transistors (O-TFTs), organic light-emitting transistors (O-LETs), organic solar cells (O-SCs), organic optical detectors, organic photoreceptors, organic field-quench devices (O-FQDs) and organic electrical sensors, preferably organic electroluminescent devices (OLEDs, sOLEDs, PLEDs, LECs, etc.), particularly preferably organic light-emitting diodes (OLEDs), organic light-emitting diodes based on small molecules (sOLEDs), organic light-emitting diodes based on polymers (PLEDs), in particular phosphorescent OLEDs.

[0120] The organic electroluminescent device contains a cathode, an anode, and at least one emitting layer. In addition to these layers, it may contain further layers, for example, one or more hole-injection layers, hole-transport layers, hole-blocking layers, electron-transport layers, electron-injection layers, exciton-blocking layers, electron-blocking layers, and / or charge-generation layers. Interlayers, which, for example, have an exciton-blocking function, may also be inserted between two emitting layers. It should be noted, however, that not all of these layers are necessarily present. The organic electroluminescent device may contain one emitting layer or it may contain multiple emitting layers.If multiple emission layers are present, they preferably have a total of multiple emission maxima between 380 nm and 750 nm, resulting in overall white emission. This means that different emitting compounds that can fluoresce or phosphoresce are used in the emitting layers. Systems with three emitting layers are particularly preferred, with the three layers exhibiting blue, green, and orange or red emission. The organic electroluminescent device according to the invention can also be a tandem electroluminescent device, particularly for white-emitting OLEDs.

[0121] The compound according to the invention can be used in different layers, depending on the precise structure. An organic electroluminescent device comprising a compound according to formula (I) or the preferred embodiments described above in an emitting layer is preferred as a matrix material for phosphorescent emitters or for emitters exhibiting TADF (thermally activated delayed fluorescence), in particular for phosphorescent emitters. Furthermore, the compound according to the invention can also be used in an electron-transport layer and / or in a hole-blocking layer.The compound according to the invention is particularly preferably used as a matrix material for phosphorescent emitters, in particular for red, orange, blue, green or yellow, preferably for blue or green phosphorescent emitters, in an emitting layer, as a host material, electron transport material, electron injection material or hole blocking material.

[0122] Preferably, it can be provided that the organic electroluminescent device comprises at least one emission layer and at least one electron transport layer and the electron transport layer contains the compound according to the present invention.

[0123] If the compound according to the invention is used as a matrix material for a phosphorescent compound in an emitting layer, it is preferably used in combination with one or more phosphorescent materials (triplet emitters). Phosphorescence, within the meaning of this invention, is understood to mean luminescence from an excited state with higher spin multiplicity, i.e., a spin state > 1, in particular from an excited triplet state. For the purposes of this application, all luminescent complexes with transition metals or lanthanides, in particular all indium, platinum, and copper complexes, are to be considered phosphorescent compounds.

[0124] The mixture of the compound according to the invention and the emitting compound contains between 99 and 1 vol.%, preferably between 98 and 10 vol.%, particularly preferably between 97 and 60 vol.%, in particular between 95 and 80 vol.% of the compound according to the invention, based on the total mixture of emitter and matrix material. Accordingly, the mixture contains between 1 and 99 vol.%, preferably between 2 and 90 vol.%, particularly preferably between 3 and 40 vol.%, in particular between 5 and 20 vol.% of the emitter, based on the total mixture of emitter and matrix material.

[0125] In one embodiment of the invention, the compound according to the invention is used as the sole matrix material (“single host”) for the phosphorescent emitter.

[0126] A further embodiment of the present invention is the use of the compound according to the invention as a matrix material for a phosphorescent emitter in combination with another matrix material. Suitable matrix materials that can be used in combination with the compounds according to the invention are aromatic ketones, aromatic phosphine oxides or aromatic sulfoxides or sulfones, e.g., according to WO 2004 / 013080, WO 2004 / 093207, WO 2006 / 005627, or WO 2010 / 006680, triarylamines, carbazole derivatives, e.g., B. CBP (N,N-biscarbazolylbiphenyl) or those in WO 2005 / 039246, US 2005 / 0069729, JP 2004 / 288381, EP 1205527, WO 2008 / 086851 or WO 2013 / 041176, indolocarbazole derivatives, e.g. according to WO 2007 / 063754 or WO 2008 / 056746, indenocarbazole derivatives, e.g. according to WO 2010 / 136109, WO 2011 / 000455, WO 2013 / 041176 or WO 2013 / 056776, azacarbazole derivatives, e.g. B. according to EP 1617710, EP 1617711 , EP 1731584, JP 2005 / 347160, bipolar matrix materials, e.g.according to WO 2007 / 137725, silanes, e.g. according to WO 2005 / 111172, azaboroles or boronate esters, e.g. according to WO 2006 / 117052, triazine derivatives, e.g. according to WO 2007 / 063754, WO 2008 / 056746, WO 2010 / 015306, WO 2011 / 057706, WO 2011 / 060859 or WO 2011 / 060877, zinc complexes, e.g. according to EP 652273 or WO 2009 / 062578, diazasilole or tetraazasilole derivatives, e.g. according to WO 2010 / 054729, diazaphosphole derivatives, e.g. B. according to WO 2010 / 054730, bridged carbazole derivatives, e.g. according to WO 2011 / 042107, WO 2011 / 060867, WO 2011 / 088877 and WO 2012 / 143080, triphenylene derivatives, e.g. according to WO 2012 / 048781, dibenzofuran derivatives, e.g. according to WO 2015 / 169412, WO 2016 / 015810, WO 2016 / 023608, WO 2017 / 148564 or WO 2017 / 148565 or biscarbazoles, e.g. according to JP 3139321 B2.

[0127] Here, the concentration of a compound according to formula (I), as described above or preferably described, in the mixture according to the invention or in the light-emitting layer of the device according to the invention is usually in the range from 10 wt.% to 95 wt.%, preferably in the range from 15 wt.% to 90 wt.%, more preferably in the range from 15 wt.% to 80 wt.%, even more preferably in the range from 20 wt.% to 70 wt.%, very particularly preferably in the range from 40 wt.% to 80 wt.% and most preferably in the range from 50 wt.% to 70 wt.%, based on the total mixture or based on the total composition of the light-emitting layer.

[0128] Likewise, another phosphorescent emitter, which emits at a shorter wavelength than the actual emitter, can be present in the mixture as a co-host. Particularly good results are achieved when a red-phosphorescent emitter is used as the emitter and a yellow-phosphorescent emitter is used as the co-host in combination with the compound according to the invention.

[0129] Furthermore, a compound can be used as co-host which does not participate, or does not participate to a significant extent, in charge transport, as described, for example, in WO 2010 / 108579. In particular, compounds which have a large band gap and themselves do not participate, or at least do not participate to a significant extent, in the charge transport of the emitting layer are suitable as co-matrix material in combination with the compound according to the invention. Such materials are preferably pure hydrocarbons. Examples of such materials can be found, for example, in WO 2009 / 124627 or WO 2010 / 006680. In this context, it should be noted that compounds according to the invention without special functional groups, for example hole transport groups and / or electron transport groups, have advantageous properties.

[0130] Particularly suitable phosphorescent compounds (= triplet emitters) are compounds that emit light upon suitable excitation, preferably in the visible range, and also contain at least one atom with an atomic number greater than 20, preferably greater than 38 and less than 84, particularly preferably greater than 56 and less than 80, in particular a metal with this atomic number. Compounds containing copper, molybdenum, tungsten, rhenium, ruthenium, osmium, rhodium, iridium, palladium, platinum, silver, gold, or europium are preferably used as phosphorescent emitters, in particular compounds containing iridium or platinum.

[0131] The term "phosphorescent emitters" typically encompasses compounds in which light emission occurs through a spin-forbidden transition from an excited state with higher spin multiplicity, i.e., a spin state > 1, for example, through a transition from a triplet state or a state with an even higher spin quantum number, such as a quintet state. Preferably, this refers to a transition from a triplet state.

[0132] In general, all phosphorescent complexes as used in the prior art for phosphorescent OLEDs and as known to the person skilled in the art in the field of organic electroluminescent devices are suitable. Preferred examples of phosphorescent emitters are described in

[0133] WO201 9 / 007867 on pages 120 to 126 in Table 5 and on pages 127 to 129 in Table 6. The emitters are incorporated into the description by this reference.

[0134] Examples of phosphorescent dopants are listed in the following table.

[0135]

[0136]

[0137] The compounds of the invention are also particularly suitable as matrix materials for phosphorescent emitters in organic electroluminescent devices, as described, for example, in WO 98 / 24271, US 2011 / 0248247, and US 2012 / 0223633. In these multi-color display components, an additional blue emission layer is vapor-deposited over the entire surface of all pixels, even those with a color other than blue.

[0138] In a further embodiment of the invention, the organic electroluminescent device according to the invention does not contain a separate hole injection layer and / or hole transport layer and / or hole blocking layer and / or electron transport layer, i.e. the emitting layer directly adjoins the hole injection layer or the anode, and / or the emitting layer directly adjoins the electron transport layer or the electron injection layer or the cathode, as described, for example, in WO 2005 / 053051. Furthermore, it is possible to use a metal complex that is the same as or similar to the metal complex in the emitting layer as a hole transport or hole injection material directly adjacent to the emitting layer, as described, for example, in WO 2009 / 030981.

[0139] In the further layers of the organic electroluminescent device according to the invention, all materials commonly used in the prior art can be used. Therefore, the skilled person can, without inventive step, use all materials known for organic electroluminescent devices in combination with the compounds according to formula (I) according to the invention or the preferred embodiments described above.

[0140] Also preferred is an organic electroluminescent device, characterized in that one or more layers are coated using a sublimation process. The materials are sublimated in vacuum sublimation systems at an initial pressure of less than 10' 5 mbar, preferably less than 10' 6 mbar. However, it is also possible that the initial pressure is even lower, for example less than 10' 7 mbar.

[0141] Also preferred is an organic electroluminescent device, characterized in that one or more layers are coated using the OVPD (Organic Vapor Phase Deposition) process or by means of carrier gas sublimation. The materials are sublimated at a pressure between 10' 5mbar and 1 bar. A special case of this process is the OVJP (Organic Vapor Jet Printing) process, in which the materials are applied directly through a nozzle and thus structured. Also preferred is an organic electroluminescent device, characterized in that one or more layers are produced from solution, for example by spin coating, or using any printing process, such as screen printing, flexographic printing, offset printing, LITI (Light Induced Thermal Imaging, thermal transfer printing), inkjet printing, or nozzle printing. Soluble compounds are required for this, which can be obtained, for example, by suitable substitution.

[0142] Formulations for applying a compound according to formula (I) or the preferred embodiments thereof set out above are novel. A further subject of the present invention is therefore a formulation comprising at least one solvent and a compound according to formula (I) or the preferred embodiments thereof set out above.

[0143] Furthermore, hybrid processes are possible, in which, for example, one or more layers are applied from solution and one or more further layers are vapor-deposited.

[0144] These processes are generally known to the person skilled in the art and can be applied by him without inventive step to organic electroluminescent devices containing the compounds according to the invention.

[0145] The compounds according to the invention and the organic electroluminescent devices according to the invention are distinguished from the prior art in particular by improved efficiency or operating voltage. The other electronic properties of the electroluminescent devices, such as lifetime, remain at least as good. In a further variant, the compounds according to the invention and the organic electroluminescent devices according to the invention are distinguished from the prior art in particular by improved efficiency and / or operating voltage and a longer lifetime. Furthermore, these compounds and the organic electroluminescent devices obtainable therefrom exhibit a low refractive index (RI).

[0146] The electronic devices according to the invention, in particular organic electroluminescent devices, are characterized by one or more of the following surprising advantages over the prior art:

[0147] 1. Electronic devices, in particular organic electroluminescent devices containing compounds of formula (I) or the preferred embodiments described above and below, in particular as matrix material or as electron-conducting materials, exhibit excellent efficiency. Compounds of the invention according to formula (I) or the preferred embodiments described above and below achieve a low operating voltage when used in electronic devices.

[0148] 2. Electronic devices, in particular organic electroluminescent devices containing compounds according to formula (I) or the preferred embodiments described above and below, in particular as matrix material or as electron-conducting materials, exhibit a very long lifetime. These compounds, in particular, result in low roll-off, i.e., a low drop in the power efficiency of the device at high luminance levels.

[0149] 3. The compounds according to the invention according to formula (I) or the preferred embodiments described above and below show very high stability.

[0150] 4. Electronic devices, in particular organic electroluminescent devices containing compounds according to formula (I) or the preferred embodiments described above and below, in particular as matrix material or as electron-conducting materials, have a very low refractive indices.

[0151] 5. Using compounds according to formula (I) or the preferred embodiments described above and below, the formation of optical loss channels can be avoided in electronic devices, particularly organic electroluminescent devices. As a result, these devices are characterized by high PL and thus high EL efficiency of emitters and excellent energy transfer from the matrices to dopants.

[0152] 6. Compounds according to formula (I) or the preferred embodiments described above and below have excellent glass film formation.

[0153] These advantages mentioned above are not accompanied by an excessive deterioration of the other electronic properties.

[0154] It should be noted that variations of the embodiments described in the present invention fall within the scope of this invention. Any feature disclosed in the present invention may, unless explicitly excluded, be replaced by alternative features serving the same, equivalent, or similar purpose. Thus, unless otherwise stated, any feature disclosed in the present invention is to be considered an example of a generic series or an equivalent or similar feature.

[0155] All features of the present invention may be combined with one another in any way, unless certain features and / or steps are mutually exclusive. This applies in particular to preferred features of the present invention. Likewise, features of non-essential combinations may be used separately (and not in combination). It should further be noted that many of the features, and in particular those of the preferred embodiments of the present invention, are inventive in their own right and are not to be considered merely as part of the embodiments of the present invention. Independent protection may be sought for these features in addition to or alternatively to any presently claimed invention.

[0156] The teaching of technical action disclosed in the present invention can be abstracted and combined with other examples.

[0157] The invention is further illustrated by the following examples, without intending to limit it. From these descriptions, one skilled in the art can practice the invention within the entire disclosed scope and, without inventive step, prepare further compounds according to the invention and use them in electronic devices or apply the method according to the invention.

[0158] Examples:

[0159] Unless otherwise stated, the following syntheses were carried out under a protective gas atmosphere in dried solvents. The solvents and reagents can be purchased from Sigma-Aldrich or ABCR, for example. The respective information in square brackets or the numbers given for individual compounds refer to the CAS numbers of the known compounds. For compounds that can exhibit multiple enantiomeric, diastereomeric, or tautomeric forms, one form is shown as a representative example.

[0160]

[0161] A) Synthesis of the compounds according to the invention:

[0162] Example 1 :

[0163] Preparation according to L. Gan et al., J. Phys. Chem. Lett. 2018, 9, 4725-4731. Preparation: 14.8 g (50 mmol) B,B'-(tricyclo[8.2.2.2 4 ' 7 ]hexadeca- 4,6, 10, 12, 13, 15-hexaen-5, 11 -diyl)bis-boronic acid [1231169-23-5] and 25.4 g (100 mmol) of 1,3-dicyano-2-iodobenzene [81725-16-8]. The crude product is purified by chromatography (Torrent column system from A. Semrau) and / or repeated hot extraction crystallization (conventional organic solvents or combinations thereof, preferably acetonitrile-DCM, 1:3 to 3:1 vv) as well as fractional sublimation or annealing under high vacuum. Yield: 14.7 g (32 mmol) 64%; Purity: approx. 99.9% by HPLC.

[0164] The following connections can be represented analogously.

[0165] Example: Production of OLEDs

[0166] The production of OLEDs according to the invention as well as OLEDs according to the prior art is carried out according to a general process according to WO 2004 / 058911 , which is adapted to the conditions described here (layer thickness variation, materials used).

[0167] The following examples present the results of various OLEDs. Cleaned glass plates (cleaned in a Miele laboratory dishwasher, using Merck Extran cleaner) coated with 50 nm thick structured ITO (indium tin oxide) are pretreated with UV ozone for 25 minutes (UV ozone generator PR-100, UVP). These coated glass plates form the substrates onto which the OLEDs are applied. a) Blue Fluorescence OLED Devices - BF:

[0168] The compounds B according to the invention can be used in the hole-blocking layer (HBL) and the electron-transport layer (ETL). All materials are thermally vapor-deposited in a vacuum chamber. The emission layer (EML) always consists of at least one matrix material (host material) SMB (see Table 1) and an emitting dopant (dopant, emitter) D, which is admixed to the matrix material(s) by co-evaporation in a specific volume fraction. A value such as SMB:D (97%:3%) means that the SMB material is present in the layer in a volume fraction of 97% and the dopant D in a volume fraction of 3%. Analogously, the electron-transport layer can also consist of a mixture of two materials, see Table 1. The materials used to produce the OLEDs are shown in Table 5.

[0169] The OLEDs are characterized as standard. For this purpose, the electroluminescence spectra, current efficiency (measured in cd / A), power efficiency (measured in λ / W), and external quantum efficiency (EQE, measured in percent) are determined as a function of luminance, calculated from current-voltage-luminance (IUL) curves assuming a Lambertian radiation pattern. The EQE (%) and voltage (V) are expressed at a luminance of 1000 cd / m². 2

[0170] The OLEDs have the following layer structure:

[0171] Substrat

[0172] Hole injection layer (HIL) made of HTM1 doped with 5% NDP-9 (commercially available from Novaled), 20 nm

[0173] Hole transport layer (HTL), made of HTM1, 180 nm

[0174] Electron blocking layer (EBL), see Table 1

[0175] Emission layer (EML), see Table 1

[0176] Hole blocking layer (HBL), see Table 1

[0177] Electron transport layer (ETL), see Table 1

[0178] Electron injection layer (EIL) made of ETM2, 1 nm Cathode made of aluminum, 100 nm

[0179] Table 1 : Structure of blue fluorescent OLED components

[0180] Table 2: Results of blue fluorescent OLED devices b) Phosphorescent OLED components:

[0181] The compounds B according to the invention can be used in the hole-blocking layer (HBL), the electron-transport layer (ETL), and in the emission layer (EML) as electron-conducting matrix material (host material) (eTMM). For this purpose, all materials are thermally vapor-deposited in a vacuum chamber. The emission layer always consists of at least one or more matrix materials M and a phosphorescent dopant Ir, which is admixed to the matrix material(s) by co-evaporation in a specific volume fraction. A specification such as M1:M2:Ir (55%:35%:10%) means that the material M1 is present in the layer in a volume fraction of 55%, M2 in a volume fraction of 35%, and Ir in a volume fraction of 10%. Analogously, the electron-transport layer can also consist of a mixture of two materials. The exact structure of the OLEDs can be found in Table 3.The materials used to manufacture the OLEDs are shown in Table 5.

[0182] The OLEDs are characterized as standard. For this purpose, the electroluminescence spectra, current efficiency (measured in cd / A), power efficiency (measured in λ / W), and external quantum efficiency (EQE, measured in percent) are determined as a function of luminance, calculated from current-voltage-luminance (IUL) curves assuming a Lambertian radiation pattern. The EQE (%) and voltage (V) are expressed at a luminance of 1000 cd / m². 2

[0183] The OLEDs have the following layer structure:

[0184] Substrat

[0185] Hole injection layer (HIL) made of HTM1 doped with 5% NDP-9 (commercially available from Novaled), 20 nm

[0186] Hole transport layer (HTL) made of HTM1, 180 nm for blue, 50 nm for green, yellow and red

[0187] Electron blocking layer (EBL), see Table 3

[0188] Emission layer (EML), see Table 3

[0189] Hole blocking layer (HBL), see Table 3

[0190] Electron transport layer (ETL), see Table 3

[0191] Electron injection layer (EIL) made of ETM2, 1 nm

[0192] Cathode made of aluminum, 100 nm Table 3: Structure of phosphorescent OLED components

[0193] Table 4: Results of phosphorescent OLED devices

[0194] Table 5: Structural formulas of the materials used

Claims

Patent claims 1. Compound according to formula (I), where the ring Ar z represents an aromatic ring system with 6 to 60 aromatic ring atoms, which is substituted by one or more radicals R z may be substituted, wherein the aromatic ring system may contain Si atoms or Ge atoms which are not directly linked to one another via a bond, and the aromatic ring system may comprise one or more ring elements with one or two O atoms and 6 ring atoms, wherein an O atom is not directly linked to an O atom, Si atom or Ge atom via a bond; the index I represents an integer in the range from 1 to 10 and Ar CN a group of the following formula (Ar c ) Formula (Ar c ), where X stands for CR or N, where at most 2 non-adjacent symbols X stand for N, and the dashed bond represents the attachment point of the group Ar CNto the Ring Ar z means; where the other symbols apply: R z represents, identically or differently at each occurrence, H, D, F, CN, C(Ar')3, C(R 1 )3, Si(Ar')3, Si(R 1 )3, Ge(Ar')3, Ge(R 1 )3, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, each of which is substituted by one or more radicals R 1 may be substituted, with one or more non-adjacent CH2 groups being replaced by -R 1 C=CR 1 -, Si(R 1 )2 and Ge(R 1 )2, and wherein one or more H atoms may be replaced by D, F or CN, or an aromatic ring system with 6 to 24 aromatic ring atoms, each of which is replaced by one or more radicals R 1 can be substituted, two substituents R z form a ring system, where, if two substituents R ztogether form a ring system, this can comprise several ring elements with 6 ring atoms containing an O; R represents, identically or differently at each occurrence, H, D, F, C(Ar')3, C(R 1 )3, Si(Ar')3, Si(R 1 )3, Ge(Ar')3, Ge(R 1 )3, a straight-chain alkyl group having 1 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, each of which is substituted by one or more radicals R 1 may be substituted, with one or more non-adjacent CH2 groups being replaced by -R 1 C=CR 1 -, Si(R 1 )2 Ge(R 1 )2 and where one or more H atoms can be replaced by D or F, or an aromatic ring system with 6 to 24 aromatic ring atoms, each of which is replaced by one or more radicals R 1 can be substituted, two substituents R can form a ring system with each other; Ar' is at each occurrence, identically or differently, an aromatic ring system with 6 to 60 aromatic ring atoms, which is substituted with one or more radicals R 1 may be substituted, whereby two radicals Ar' which bind to the same C-atom, Si-atom or Ge-atom may also be connected by a single bond or a bridge selected from C(R 1 )2, Si(R 1 )2 and Ge(R 1 )2, be bridged together; R 1 is the same or different at each occurrence: H, D, F, CN, C(Ar”)3, C(R 2 )3, Si(Ar”)3, Si(R 2 )3, Ge(Ar”)3, Ge(R 2 )3, a straight-chain alkyl group having 1 to 40 C atoms or a branched or cyclic alkyl group having 3 to 40 C atoms or an alkenyl group having 2 to 40 C atoms, each of which is substituted by one or more radicals R 2 may be substituted, wherein one or more non-adjacent CH2 groups are substituted by - R 2 C=CR 2 -, -C=C-, Si(R 2 )2 or Ge(R2 )2 and where one or more H atoms can be replaced by D, F or CN, or an aromatic ring system with 6 to 60 aromatic ring atoms, each of which is replaced by one or more radicals R 2 may be substituted; two or more radicals R 1 form a ring system with each other; Ar” is at each occurrence, identically or differently, an aromatic ring system with 5 to 30 aromatic ring atoms, which is substituted with one or more radicals R 2 may be substituted, whereby two radicals Ar” which bind to the same C-atom, Si-atom or Ge-atom may also be connected by a single bond or a bridge selected from C(R 2 )2, Si(R 2 )2, and Ge(R 2 ), be bridged together; R 2is selected, identically or differently at each occurrence, from the group consisting of H, D, F, CN, an aliphatic hydrocarbon radical having 1 to 20 C atoms or an aromatic ring system having 6 to 30 aromatic ring atoms, in which one or more H atoms may be replaced by D, F, or CN and which may be substituted by one or more alkyl groups each having 1 to 4 carbon atoms, where two or more substituents R 2 form a ring system with each other; wherein the compound according to formula (I) does not comprise an anthracene group and a fluoranthene group.

2. A compound according to claim 1, characterized in that the group Ar z is selected from structures of the formulas (Ar z -1 ) to (Ar z -14) where the structures of the structures of the formulas (Ar z -1 ) to (Ar z -14) with one or more residues R zmay be substituted and the other symbols have the following meaning: n, m is each independently 0 or 1 , where 0 means that the group Y is not present; Y is C(R Z )2, Si(R z )2, Ge(R z )2, C(R Z )=C(R Z ), an ortho-linked arylene group, a bond or 0; W is C, Si or Ge; Z is C(R Z )2, Si(R z )2, Ge(R z )2or 0; and R z has the meaning given in claim 1.

3. A compound according to claim 1 or 2, characterized in that the group Ar z is selected from structures of the formulas (Ar z -1 a) to Formula (Ar z -12e) Formula (Ar z -13a) Formula (Ar z-14b) where the dashed bond or the dashed bonds are the attachment site(s) of the ring Ar z to the Group / Groups Ar CN marked / mark and the other symbols have the following meaning: n, m is each independently 0 or 1 , where 0 means that the group Y is not present and the corresponding carbon atoms are instead bound to radicals R z are bound; Y is C(R Z )2, Si(R z )2, Ge(R z )2, C(R Z )=C(R Z ), an ortho-linked arylene group, a bond or 0; W is C, Si or Ge; Z is C(R Z )2, Si(R z )2, Ge(R z )2 or 0; k is 0 or 1; i is 0, 1 or 2; j is 0, 1, 2 or 3; h is 0, 1, 2, 3 or 4; g is 0, 1, 2, 3, 4 or 5; and R z has the meaning given in claim 1.

4. A compound according to one or more of claims 1 to 3, characterized in that the compound according to formula (I) has at least one fluorene group or one spiro group.

5. A compound according to one or more of claims 1 to 4, characterized in that the index I in formula (I) is an integer in the range from 2 to 6.

6. A compound according to one or more of claims 1 to 5, characterized in that the compound corresponds to one of the following formulas (II-1) to (II-34): Formula (11-1 ) Formula (II-2) where the symbols R and R zhas the meaning given in claim 1, the indices and symbols n, m, Y, W and Z have the meanings given in claim 2, and furthermore: k is 0 or 1; i is 0, 1 or 2; j is 0, 1, 2 or 3; h is 0, 1, 2, 3 or 4; and g is 0, 1, 2, 3, 4 or 5.

7. A compound according to one or more of claims 1 to 6, characterized in that the group Ar CN is selected from structures of the formulas (Ar c -1 ) to (Ar c -3) and / or the group in formulas (II-1) to (II-34) is selected from structures of the formulas (Ar c -1 ) to (Ar c -3) where the dashed bond or bonds represent the attachment point of the group Ar CN to the Ring Ar z marked and the other symbols have the following meaning: R a is F, H or D; R bis an aromatic ring system with 6 to 24 aromatic ring atoms, each connected by one or more radicals R 1 may be substituted, where R 1 has the meaning given in claim 1.

8. A compound according to claim 7, characterized in that the compound according to formula (I) contains at least one group Ar CN according to formula (Ar c -3).

9. A compound according to one or more of claims 1 to 8, characterized in that the compound corresponds to one of the following formulas (III-1) to (III-64): Formula (III-3) Formula (III-4) Formula (III-63) Formula (III-64) where the symbol R zhas the meaning given in claim 1, the symbols and indices n, m, Y, W and Z have the meanings given in claim 2, the symbols R a and R b have the meanings given in claim 9 and furthermore: k is 0 or 1; i is 0, 1 or 2; j is 0, 1, 2 or 3; h is 0, 1, 2, 3 or 4; and g is 0, 1, 2, 3, 4 or 5.

10. A compound according to one or more of claims 1 to 9, characterized in that at least one radical R, R z is selected, identically or differently at each occurrence, from the group consisting of an aromatic ring system selected from the Groups of the following formulas Ar-1 to Ar-40 and / or the group Ar' is selected, identically or differently at each occurrence, from the groups of the following formulas Ar-1 to Ar-40 where R 1has the meanings given above, the dashed bond represents the bond to the corresponding group and furthermore: Ar 1 is at each occurrence, identically or differently, a bivalent aromatic ring system with 6 to 18 aromatic ring atoms, each substituted by one or more radicals R 1 can be substituted; A is the same or different at each occurrence C(R 1 )2; p is 0 or 1 , where p = 0 means that the group Ar 1 is not present and that the corresponding aromatic group is directly bonded to the corresponding residue; q is 0 or 1, where q = 0 means that no group A is bonded to this position and that the corresponding carbon atoms are bonded instead to residues R 1 are bound. 11 . A compound according to at least one of the preceding claims, characterized in that the compound comprises at least 4 aryl radicals.

12. Formulation containing at least one compound according to one or more of claims 1 to 11 and at least one further Compound, wherein the further compound is preferably selected from one or more solvents.

13. Composition comprising at least one compound according to one or more of claims 1 to 11 and at least one further compound selected from the group consisting of fluorescent emitters, phosphorescent emitters, emitters exhibiting TADF, host materials, electron transport materials, electron injection materials, hole conductor materials, hole injection materials, electron blocking materials and hole blocking materials, preferably host materials.

14. Use of a compound according to one or more of claims 1 to 11 in an electronic device, preferably as host material, electron injection material, electron transport material or hole blocking material, particularly preferably as electron injection material, electron transport material or hole blocking material.

15. Electronic device comprising at least one compound according to one or more of claims 1 to 11.

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