Mononuclear tripodal hexadentate iridium complexes for OLEDs

Abstract

The present invention relates to iridium complexes suitable for use in organic electroluminescent devices, in particular as emitters.

Description

[0001] The present invention relates to iridium complexes which are suitable for use in organic electroluminescent devices, in particular as emitters.

[0002] According to the prior art, the triplet luminophores used in phosphorescent organic electroluminescent devices (OLEDs) are particularly double- and three-ortho-metallated iridium complexes with aromatic ligands, wherein the ligands are coordinated via negatively charged carbon atoms and uncharged nitrogen atoms. Examples of such complexes are tris(phenylpyridyl)iridium (III) and derivatives thereof. Complexes of this type with multi-foot ligands are also known, as described in, for example, US 7,332,232, WO 2016 / 124304 and WO 2019 / 158453. Although these complexes with multi-foot ligands show advantages over complexes with the same ligand structure and wherein a single ligand does not have multi-foot bridging, for example, still need to be improved in terms of efficiency, voltage and lifespan.

[0003] The problem addressed by the present invention was therefore to provide improved iridium complexes which are suitable as emitters for use in OLEDs.

[0004] Surprisingly, it has been found that iridium complexes with hexadentate tripodal ligands having the structure described below solve this problem and are very suitable for use in organic electroluminescent devices. The present invention therefore provides these iridium complexes and organic electroluminescent devices comprising these complexes.

[0005] The present invention thus provides a compound of formula (I),

[0006] Ir(L) Formula (1)

[0007] The ligand L has the structure of the following formula (2):

[0008]

[0009] The ligand L is coordinated to the iridium atom via the position indicated by *, and hydrogen atoms not explicitly shown therein may also be replaced by D, and the symbols and notations used therein are as follows:

[0010] R is in each case identical or different and is: H, D, F, a straight-chain alkyl radical having 1 to 10 carbon atoms or a branched or cyclic alkyl radical having 3 to 10 carbon atoms, wherein the alkyl radical may in each case also be deuterated; in this case, two adjacent R radicals may together form a ring system;

[0011] R 1are in each case identical or different and are: H, D, a straight-chain alkyl radical having 1 to 10 carbon atoms or a branched or cyclic alkyl radical having 3 to 10 carbon atoms, wherein the alkyl radical may in each case also be deuterated; in this case, two adjacent R 1 The groups may together form a ring system;

[0012] R 2 are in each case identical or different and are: H, D, a straight-chain alkyl radical having 1 to 10 carbon atoms, a branched or cyclic alkyl radical having 3 to 10 carbon atoms, wherein the alkyl radicals may in each case also be deuterated, or a phenyl or biphenyl radical, which may each be substituted by one or more alkyl radicals having 1 to 10 carbon atoms, wherein the phenyl or biphenyl radical or the alkyl radical may each also be deuterated; in this case, two adjacent R 2 The groups may together form a ring system;

[0013] m is 1, 2 or 3;

[0014] n is in each case identical or different and is 0, 1, 2 or 3;

[0015] o is 0 or 1;

[0016] p is 0, 1, or 2;

[0017] q is 0, 1, or 2;

[0018] r is 0, 1 or 2.

[0019] Thus, the ligand L of formula (2) is a hexadentate tripodal ligand having three bidentate phenylpyridine subligands. The complex Ir(L) of formula (1) formed by this ligand thus has the following structure:

[0020]

[0021] The symbols and indices therein have the definitions given above.

[0022] When two R groups or two R 1 Group or two R 2 When the groups together form a ring system, the ring system may be monocyclic or polycyclic. In this case, the groups that together form a ring system are adjacent, meaning that these groups are combined with carbon atoms that are directly bonded to each other. In the context of this specification, the phrase that two R groups can together form a ring is to be understood to mean, in particular, that the two groups are connected to each other by a chemical bond under the formal elimination of two hydrogen atoms. This is illustrated by the following scheme:

[0023]

[0024] Cyclic alkyl groups in the context of the present invention are understood to mean monocyclic, bicyclic or polycyclic groups.

[0025] In the context of the present invention, C1- to C 10 -Alkyl groups are understood to mean, for example: methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, cyclobutyl, 2-methylbutyl, n-pentyl, sec-pentyl, tert-pentyl, 2-pentyl, neopentyl, cyclopentyl, n-hexyl, sec-hexyl, tert-hexyl, 2-hexyl, 3-hexyl, neohexyl, cyclohexyl, 1-methylcyclopentyl, 2-methylpentyl, n-heptyl, 2-heptyl, 3-heptyl, 4-heptyl, cycloheptyl, 1-methylcyclohexyl, n-oct ... 1-(n-propyl)cyclohexan-1-yl and 1-(n-butyl)cyclohexan-1-yl radicals.

[0026] When the indices n, p, q and r are 0, a hydrogen or deuterium atom is bonded to the corresponding phenyl or pyridine radical in each case instead of the corresponding substituent.

[0027] When m=1, the ligand L is preferably a structure of the following formula (3a); when m=2, the ligand L is preferably a structure of the following formula (3b) or (3c); when m=3, the ligand L is preferably a structure of the following formula (3d) or (3e):

[0028]

[0029]

[0030] The symbols and indices therein have the meanings given above and hydrogen atoms not explicitly shown may also be replaced by deuterium.

[0031] Preferred is the structure of formula (3a).

[0032] When o=1, a preferred embodiment is q=0 and p=0, 1 or 2, or q=0, 1 or 2 and p=0. When o=1 and p=1, the ligand preferably has the structure of the following formula (4a), and when o=1 and p=2, the ligand preferably has the structure of the following formula (4b):

[0033]

[0034] The symbols and indices therein have the meanings given above and hydrogen atoms not explicitly shown may also be replaced by deuterium.

[0035] In a preferred embodiment of the invention, the n markers on the two phenylpyridine subligands which are not substituted by cyanophenyl or cyanobiphenyl groups are 0. In another preferred embodiment of the invention, these n markers are 1 or 2, and the corresponding R 1 The group is not H or D. When these markers n are 1, the ligand preferably has the structure of the following formula (5a) or (5b), and when these markers n are 2, the ligand preferably has the structure of the following formula (5c):

[0036]

[0037]

[0038] The symbols and notations have the definitions given above and R 1 Hydrogen atoms which are not H or D and which are not explicitly shown may also be replaced by deuterium.

[0039] In another preferred embodiment of the present invention, the label n on the phenylpyridine subligand substituted with a cyanophenyl or cyanobiphenyl group is 0. In another preferred embodiment of the present invention, the label n is 1 or 2, and the corresponding R 2 The group is not H or D. When the label n is 1, the ligand preferably has the structure of the following formula (6a) or (6b), and when the label n is 2, the ligand preferably has the structure of the following formula (6c):

[0040]

[0041]

[0042] The symbols and notations have the definitions given above and R 2 Hydrogen atoms which are not H or D and which are not explicitly shown may also be replaced by deuterium.

[0043] The ligand L preferably has the structure of the following formula (7):

[0044]

[0045] The symbols and indices therein have the meanings given above and hydrogen atoms not explicitly shown may also be replaced by deuterium.

[0046] In a preferred embodiment of the invention, the substituents R are identical or different in each case and are selected from D, linear alkyl groups having 1 to 6 carbon atoms or branched or cyclic alkyl groups having 3 to 6 carbon atoms, wherein each of the alkyl groups may also be deuterated. More preferably, the substituents R are identical or different in each case and are selected from D, linear alkyl groups having 1 to 4 carbon atoms or branched alkyl groups having 3 or 4 carbon atoms, wherein each of the alkyl groups may also be deuterated. Particularly preferably, R is a methyl group or a CD3 group.

[0047] In another preferred embodiment of the present invention, the substituent R 1 are identical or different in each case and are selected from D, a straight-chain alkyl radical having 1 to 6 carbon atoms or a branched or cyclic alkyl radical having 3 to 6 carbon atoms, wherein each of the alkyl radicals may also be deuterated; in this case, two adjacent R 1 The groups may together form a ring system. More preferably, the substituent R 1 are identical or different in each case and are selected from D, a straight-chain alkyl radical having 1 to 4 carbon atoms or a branched alkyl radical having 3 or 4 carbon atoms, wherein each of the alkyl radicals may also be deuterated; in this case, two adjacent R 1 The groups may together form a ring system. Particularly preferably, R 1 It is a methyl group or a CD3 group.

[0048] In another preferred embodiment of the present invention, the substituent R 2 are identical or different in each case and are selected from: D, a linear alkyl radical having 1 to 6 carbon atoms or a branched or cyclic alkyl radical having 3 to 6 carbon atoms, wherein each of the alkyl radicals may also be deuterated, or an optionally deuterated phenyl radical which may be substituted by one or more optionally deuterated alkyl radicals having 1 to 4 carbon atoms; in this case, two adjacent R 2 The groups may together form a ring system. More preferably, the substituent R 2 are identical or different in each case and are selected from D, a straight-chain alkyl radical having 1 to 4 carbon atoms or a branched alkyl radical having 3 or 4 carbon atoms, wherein each of the alkyl radicals may also be deuterated; in this case, two adjacent R 2 The groups, when they are alkyl groups, may together form a ring system. Particularly preferably, R 2 is a methyl group or a CD3 group. 2 In the case of an optionally deuterated phenyl group, it is preferably unsubstituted or substituted by one or two optionally deuterated alkyl groups, preferably a methyl group or a CD3 group, wherein these alkyl groups are then preferably bonded to the ortho position of the bond to the phenyl group.

[0049] In another preferred embodiment of the present invention, m=1 or 2, more preferably 1.

[0050] In a further preferred embodiment of the invention, n is identical or different in each case and is 0, 1 or 2.

[0051] In another preferred embodiment of the present invention, o=1. When n on the same ligand is 1 and R 2 In the case of a phenyl group, o=1 is also preferred.

[0052] In another preferred embodiment of the present invention, p=0 or 1, more preferably 0.

[0053] In another preferred embodiment of the present invention, q=0 or 1.

[0054] In another preferred embodiment of the present invention, r=0 or 1.

[0055] Preferably, two or more of the above preferences occur simultaneously. Therefore, preferably, the symbols and markings are as follows:

[0056] R is identical or different in each case and is selected from D, a straight-chain alkyl radical having 1 to 6 carbon atoms or a branched or cyclic alkyl radical having 3 to 6 carbon atoms, wherein each of the alkyl radicals may also be deuterated;

[0057] R 1 are in each case identical or different and are selected from D, a linear alkyl radical having 1 to 6 carbon atoms or a branched or cyclic alkyl radical having 3 to 6 carbon atoms, wherein each of the alkyl radicals may also be deuterated; in this case, two adjacent R 1 The groups may together form a ring system;

[0058] R 2 are identical or different in each case and are selected from: D, a linear alkyl radical having 1 to 6 carbon atoms or a branched or cyclic alkyl radical having 3 to 6 carbon atoms, wherein each of the alkyl radicals may also be deuterated, or an optionally deuterated phenyl radical which may be substituted by one or more optionally deuterated alkyl radicals having 1 to 4 carbon atoms; in this case, two adjacent R 2 The groups may together form a ring system;

[0059] m is 1 or 2;

[0060] n is in each case identical or different and is 0, 1 or 2;

[0061] o is 1; or when n on the same ligand is 1 and R 2 When it is a phenyl group, o is 0 or 1;

[0062] p is 0 or 1;

[0063] q is 0 or 1;

[0064] r is 0 or 1.

[0065] More preferably, the symbols and indices are as follows:

[0066] R is identical or different in each case and is selected from D, a straight-chain alkyl group having 1 to 4 carbon atoms or a branched alkyl group having 3 or 4 carbon atoms, wherein each of the alkyl groups may also be deuterated;

[0067] R 1 are in each case identical or different and are selected from D, a straight-chain alkyl radical having 1 to 4 carbon atoms or a branched alkyl radical having 3 or 4 carbon atoms, wherein each of the alkyl radicals may also be deuterated; in this case, two adjacent R 1 The groups may together form a ring system;

[0068] R 2 are in each case identical or different and are selected from: D, a straight-chain alkyl radical having 1 to 4 carbon atoms or a branched alkyl radical having 3 or 4 carbon atoms, wherein each of the alkyl radicals may also be deuterated, or an optionally deuterated phenyl radical which may be substituted by one or more optionally deuterated alkyl radicals having 1 to 4 carbon atoms; in this case, two adjacent alkyl radicals R 2 Can form a ring system together;

[0069] m is 1;

[0070] n is in each case identical or different and is 0, 1 or 2;

[0071] o is 1; or when n on the same ligand is 1 and R 2 When it is a phenyl group, o is 0 or 1;

[0072] p is 0;

[0073] q is 0 or 1;

[0074] r is 0 or 1.

[0075] When two R or R 1 or R 2 When the groups are alkyl groups that form a ring system with each other, the ring system is preferably selected from the structures of the following formulae (Ring-1) to (Ring-7):

[0076]

[0077] Wherein the dashed bond indicates the bonding of two carbon atoms within the ligand, and in addition:

[0078] R 3are identical or different in each case and are H, D, or an alkyl group having 1, 2 or 3 carbon atoms;

[0079] G is an alkylene group having 1 or 2 carbon atoms.

[0080] In the structures (Ring-1) to (Ring-7) shown above, as well as other embodiments of these structures designated as preferred, a double bond in a formal sense is formed between the two carbon atoms. This is a simplification of the chemical structure, because the two carbon atoms are incorporated into an aromatic or heteroaromatic system, and therefore the bond between the two carbon atoms is formally between the single bond bonding level and the double bond bonding level. Therefore, the drawing of the formal double bond should not be interpreted as limiting the structure; rather, it will be clear to a person skilled in the art that this is an aromatic bond.

[0081] When adjacent groups in the structures of the invention form an aliphatic ring system, it is preferred that the latter does not have any acidic benzylic protons. A benzylic proton is understood to mean a proton bound to a carbon atom directly bonded to the ligand. This can be achieved by a carbon atom in an aliphatic ring system directly bonded to an aryl or heteroaryl group that is fully substituted and does not contain any bonded hydrogen atoms. For example, formulas (ring-1) to (ring-3) have R in the benzylic position. 3 is an alkyl group, resulting in the absence of acidic benzylic protons. This can also be achieved by carbon atoms in the aliphatic ring system that are directly bonded to the pyridine or phenyl groups that serve as bridgeheads in the bicyclic or polycyclic structure. Due to the steric structure of the bicyclic or polycyclic rings, the acidity of the protons bonded to the bridgehead carbon atoms is significantly lower than the benzylic protons on the carbon atoms that are not bonded in the bicyclic or polycyclic ring structure and are considered non-acidic protons in the context of the present invention.

[0082] Examples of suitable groups of structure (Ring-1) are the structures listed below:

[0083]

[0084] Examples of suitable groups of formula (Ring-2) are the structures listed below:

[0085]

[0086] Examples of suitable groups of formula (Ring-3), (Ring-6) and (Ring-7) are the structures listed below:

[0087]

[0088] Examples of suitable groups of formula (Ring-4) are the structures listed below:

[0089]

[0090] Examples of suitable groups of formula (Ring-5) are the structures listed below:

[0091]

[0092] In a particularly preferred embodiment of the present invention, the ligand L has the structure of the following formula (8):

[0093]

[0094] Among them, R 1 , R 2 and o have the definitions given above, in particular the preferred definitions given above or the particularly preferred definitions given above, p=0 or 1, q=0 or 1 and r=0 or 1, and hydrogen atoms not explicitly shown may also be replaced by deuterium.

[0095] Most preferably, the ligand L has the structure of the following formula (9):

[0096]

[0097] Among them, R 1 and R 2 Having the definitions given above, in particular the preferred definitions above or the particularly preferred definitions above, q=0 or 1 and r=0 or 1, and hydrogen atoms not explicitly shown may also be replaced by deuterium.

[0098] The above-mentioned preferred embodiments can be combined with each other as required. In a particularly preferred embodiment of the present invention, the above-mentioned preferred embodiments are applicable simultaneously.

[0099] Examples of suitable structures of the present invention are the compounds shown below.

[0100]

[0101]

[0102]

[0103]

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110]

[0111]

[0112]

[0113]

[0114]

[0115]

[0116]

[0117]

[0118]

[0119]

[0120]

[0121]

[0122]

[0123]

[0124]

[0125] The metal complex of the present invention is a chiral structure. If the ligand L is also chiral, diastereomers and multiple enantiomeric pairs can be formed. In this case, the complex of the present invention includes both mixtures of different diastereomers or corresponding racemates, and also includes individually separated diastereomers or enantiomers.

[0126] If a ligand with two identical subligands is used in the ortho-metallation, a racemic mixture of C1-symmetric complexes, i.e., a racemic mixture of Δ and λ enantiomers, is generally obtained. They can be separated by standard methods (chromatography on chiral materials / columns or optical resolution by crystallization), as shown in the following scheme:

[0127] Racemate from ortho-metallation

[0128]

[0129] Optical resolution by fractional crystallization of diastereomeric salt pairs can be achieved by conventional methods. One option for this purpose is to oxidize the uncharged Ir(III) complex (e.g., with peroxide or H2O2 or by electrochemical means), add an enantiomerically pure salt of a monoanionic base (chiral base) to the cationic Ir(IV) complex thus produced, separate the diastereomeric salts thus produced by fractional crystallization, and then reduce them with the aid of a reducing agent (e.g., zinc, hydrazine hydrate, ascorbic acid, etc.) to produce an enantiomerically pure uncharged complex, as schematically shown below:

[0130]

[0131] Additionally, enantiomerically pure or enantiomerically enriched syntheses are possible by complexation in chiral media such as R- or S-1,1-binaphthol.

[0132] If a ligand with three different subligands is used in the complexation, generally a mixture of diastereomers of the complex is obtained which can be separated by standard methods (chromatography, crystallization, etc.).

[0133] As shown in the scheme below, enantiomerically pure C1-symmetric complexes can also be selectively synthesized. For this purpose, enantiomerically pure C1-symmetric ligands are prepared and complexed, the resulting diastereomeric mixture is separated, and the chiral group is then removed.

[0134]

[0135] The compounds according to the invention can in principle be prepared by various methods. In general, for this purpose, an iridium salt is reacted with the corresponding free ligand.

[0136] Therefore, the present invention also provides a process for preparing the compounds of the present invention, said process being carried out by reacting a suitable free ligand with an iridium alkoxide of formula (Ir-1), with an iridium ketoketone of formula (Ir-2), with an iridium halide of formula (Ir-3) or with an iridium carboxylate of formula (Ir-4):

[0137]

[0138] Here R has the meaning given above, Hal═F, Cl, Br or I, and the iridium reactant may also be in the form of the corresponding hydrate. R here is preferably an alkyl group having 1 to 4 carbon atoms.

[0139] Iridium compounds which carry both alkoxy anions and / or halide anions and / or hydroxyl and keto-keto anion groups can also be used. These compounds can also be charged. WO 2004 / 085449 discloses corresponding iridium compounds which are particularly suitable as reactants. Particularly suitable are [IrCl2(acac)2] ─ , such as Na[IrCl2(acac)2], metal complexes with acetylacetonate derivatives as ligands, such as Ir(acac)3 or tris(2,2,6,6-tetramethylheptane-3,5-dione)iridium, and IrCl3·xH2O, where x is usually a number from 2 to 4.

[0140] The synthesis of the complex is preferably carried out as described in WO 2002 / 060910 and WO 2004 / 085449. The synthesis is also particularly suitable for organic acids or mixtures of organic acids and organic solvents, as described in the unpublished application EP19187468.4, and particularly suitable reaction media are, for example, acetic acid, or mixtures of salicylic acid and organic solvents such as mesitylene. In this case, the synthesis can also be activated by heat or photochemical means and / or by microwave radiation. In addition, the synthesis can also be carried out in an autoclave under high pressure and / or high temperature.

[0141] The reaction can be carried out in the melt of the corresponding ligand to be metallated without the addition of solvents or fluxes. Optionally, solvents or fluxes can also be added. Suitable solvents are protic or aprotic solvents, for example: aliphatic and / or aromatic alcohols (methanol, ethanol, isopropanol, tert-butanol, etc.), oligo- and polyols (ethylene glycol, propane-1,2-diol, glycerol, etc.), alcohol ethers (ethoxyethanol, diethylene glycol, triethylene glycol, polyethylene glycol, etc.), ethers (diethylene glycol dimethyl ether and triethylene glycol dimethyl ether, diphenyl ether, etc.), aromatic, heteroaromatic and / or aliphatic hydrocarbons (toluene, xylene, mesitylene, chlorobenzene, pyridine, lutidine, quinoline, isoquinoline, tridecane, hexadecane, etc.), amides (DMF, DMAC, etc.), lactams (NMP), sulfoxides (DMSO) or sulfones (dimethyl sulfone, cyclopentane, etc.). Suitable fluxes are compounds which are solid at room temperature but melt and dissolve the reactants when the reaction mixture is heated, thereby forming a homogeneous melt. Particularly suitable are biphenyl, m-terphenyl, triphenyl, R- or S-binaphthol or the corresponding racemates, 1,2-diphenoxybenzene, 1,3-diphenoxybenzene or 1,4-diphenoxybenzene, triphenylphosphine oxide, 18-crown-6, phenol, 1-naphthol, hydroquinone, etc. Particular preference is given here to the use of hydroquinone.

[0142] Alternatively, a complex with a reactive leaving group such as Cl, Br, I or a boronic acid derivative instead of the cyanophenyl or cyanobiphenyl group can be first synthesized and in a next step the cyanophenyl or cyanobiphenyl group can be introduced by a coupling reaction such as a Suzuki coupling reaction.

[0143] By these methods, if necessary followed by purification, for example recrystallization or sublimation, the compounds of the invention of formula (1) can be obtained in high purity, preferably in a purity greater than 99% (by 1 H NMR and / or HPLC).

[0144] In order to process the iridium complexes according to the invention from the liquid phase, for example by spin coating or by printing methods, preparations of the iridium complexes according to the invention are required. These preparations may, for example, be solutions, dispersions or emulsions. For this purpose, mixtures of two or more solvents may preferably be used. Suitable and preferred solvents are, for example, toluene, anisole, o-, m- or p-xylene, methyl benzoate, mesitylene, tetralin, o-dimethoxybenzene, THF, methyl-THF, THP, chlorobenzene, dimethoxybenzene, alkanes, phenoxytoluene, especially 3-phenoxytoluene, (-)-fenchone, 1,2,3,5-tetramethylbenzene, 1,2,4,5-tetramethylbenzene, 1-methylnaphthalene, 2-methylbenzothiazole, 2-phenoxyethanol, 2-pyrrolidone, 3-methylanisole, 4-methylanisole, 3,4-dimethylanisole, 3,5-dimethylanisole, acetophenone, α-terpineol, benzothiazole, butyl benzoate, isopropylbenzene, cyclohexanol, cyclohexanone, cyclohexylbenzene, decalin, dodecylbenzene, ethyl benzoate, indane, NMP, p-cymene, phenethyl ether, 1,4 - diisopropylbenzene, dibenzyl ether, diethylene glycol butyl methyl ether, triethylene glycol butyl methyl ether, diethylene glycol dibutyl ether, triethylene glycol dimethyl ether, diethylene glycol monobutyl ether, tripropylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, 2-isopropylnaphthalene, pentylbenzene, hexylbenzene, heptylbenzene, octylbenzene, 1,1-bis(3,4-dimethylphenyl)ethane, hexamethylindan, methylbiphenyl, 3-methylbiphenyl, 1-methylnaphthalene, 1-ethylnaphthalene, ethyl octanoate, diethyl sebacate, octyl octanoate, heptylbenzene, menthyl isovalerate, cyclohexyl hexanoate, or a mixture of these solvents.

[0145] Therefore, the present invention also provides a kind of preparation comprising at least one compound of the present invention and at least one other compound.Described other compound can be, for example, solvent, especially one of the above-mentioned solvents or the mixture of these solvents.Described other compound or can be other organic or inorganic compound used in electronic device equally, for example matrix material.This other compound can also be polymeric.

[0146] The compounds of the present invention can be used as active components in electronic devices, preferably as emitters in the light-emitting layer of organic electroluminescent devices. Therefore, the present invention also provides the use of the compounds of the present invention in electronic devices, especially in organic electroluminescent devices.

[0147] The present invention furthermore provides electronic devices, especially organic electroluminescent devices, which comprise at least one compound according to the invention.

[0148] An electronic device is understood to mean any device comprising an anode, a cathode and at least one layer, the layer comprising at least one organic compound or organometallic compound. Thus, the electronic device of the invention comprises an anode, a cathode and at least one layer containing at least one iridium complex of the invention. Preferred electronic devices are selected from: organic electroluminescent devices (OLED, PLED), organic integrated circuits (O-IC), organic field effect transistors (O-FET), organic thin film transistors (O-TFT), organic light emitting transistors (O-LET), organic solar cells (O-SC), the latter being understood to mean pure organic solar cells and dye-sensitized solar cells, organic optical detectors, organic photoreceptors, organic field quenching devices (O-FQD), light emitting electrochemical cells (LEC), oxygen sensors, and organic laser diodes (O-lasers); the electronic device comprises at least one compound of the invention in at least one layer. Infrared luminescent compounds are suitable for use in organic infrared electroluminescent devices and infrared sensors. Particularly preferred are organic electroluminescent devices. The active components are generally organic or inorganic materials introduced between the anode and the cathode, such as charge injection, charge transport or charge blocking materials, but especially luminescent materials and matrix materials. The compounds of the present invention exhibit particularly good properties as luminescent materials in organic electroluminescent devices. Therefore, a preferred embodiment of the present invention is an organic electroluminescent device. In addition, the compounds of the present invention can be used to generate singlet oxygen or for photocatalysis.

[0149] The organic electroluminescent device comprises a cathode, an anode and at least one emitting layer. In addition to these layers, it may also comprise further layers, for example in each case one or more hole injection layers, hole transport layers, hole blocking layers, electron transport layers, electron injection layers, exciton blocking layers, electron blocking layers, charge generation layers and / or organic or inorganic p / n junctions. In this case, one or more hole transport layers can be p-doped, for example with metal oxides such as MoO3 or WO3, or with (per)fluorinated electron-deficient aromatic compounds or with electron-deficient cyanide-substituted heteroaromatic compounds (for example according to JP 4747558, JP 2006-135145, US2006 / 0289882, WO 2012 / 095143), or with quinone systems (for example according to EP1336208), or with Lewis acids, or with boranes (for example according to US 2003 / 0006411, WO 2002 / 051850, WO2015 / 049030), or with carboxylates of elements of the 3rd, 4th or 5th main groups (WO 2015 / 018539), and / or one or more electron transport layers can be n-doped.

[0150] It is likewise possible to introduce interlayers between two emitting layers, which interlayers have, for example, an exciton blocking function in an electroluminescent device and / or control the charge balance and / or generate charges (charge generation layers, for example in layer systems having two or more emitting layers, for example in white-emitting OLED elements). However, it should be pointed out that not every one of these layers necessarily has to be present.

[0151] In this case, the organic electroluminescent device may contain one luminescent layer, or it may contain multiple luminescent layers. If there are multiple luminescent layers, these luminescent layers preferably have a total of multiple luminescent peaks between 380nm and 750nm, thereby producing white luminescence as a whole; in other words, a variety of luminescent compounds that can fluoresce or phosphoresce are used in the luminescent layer. Particularly preferred are three-layer systems in which three layers show blue, green and orange or red luminescence (basic structure see, for example, WO 2005 / 011013), or systems with more than three luminescent layers. The system can also be a mixed system in which one or more layers fluoresce and one or more other layers phosphoresce. A preferred embodiment is a tandem OLED. White luminescent organic electroluminescent devices can be used for lighting applications, or in combination with color filters for full-color displays.

[0152] In a preferred embodiment of the present invention, the organic electroluminescent device comprises the compound of the present invention as emitting compound in one or more emitting layers.

[0153] When the compound of the present invention is used as a luminescent compound in a luminescent layer, it is preferably used in combination with one or more host materials. Based on the total mixture of luminophore and host material, the mixture of the compound of the present invention and host material contains between 0.1 volume % and 99 volume %, preferably between 1 volume % and 90 volume %, more preferably between 3 volume % and 40 volume %, especially between 5 volume % and 15 volume % of the compound of the present invention. Accordingly, based on the total mixture of luminophore and host material, the mixture contains between 99.9 volume % and 1 volume %, preferably between 99 volume % and 10 volume %, more preferably between 97 volume % and 60 volume %, especially between 95 volume % and 85 volume % of host material.

[0154] The matrix material used may generally be any material known for this purpose according to the prior art. The triplet level of the matrix material is preferably higher than the triplet level of the emitter.

[0155] Suitable matrix materials for the compounds according to the invention are ketones, phosphine oxides, sulfoxides or sulfones, for example according to WO 2004 / 013080, WO 2004 / 093207, WO 2006 / 005627 or WO 2010 / 006680; triarylamines, carbazole derivatives, for example CBP (N,N-biscarbazolylbiphenyl) or the carbazole derivatives disclosed in WO 2005 / 039246, US 2005 / 0069729, JP 2004 / 288381, EP 1205527, WO 2008 / 086851 or US 2009 / 0134784; bicarbazole derivatives; indolocarbazole derivatives, for example according to WO 2007 / 063754 or WO 2008 / 056746; indenocarbazole derivatives, for example according to WO 2010 / 136109 or WO2011 / 000455; azacarbazole derivatives, for example according to EP 1617710, EP1617711, EP 1731584, JP 2005 / 347160; bipolar matrix materials, for example according to WO 2007 / 137725; silanes, for example according to WO 2005 / 111172; borazolidines or boric acid esters, for example according to WO 2006 / 117052; siladiazolidine derivatives, for example according to WO 2010 / 054729; phosphodiazolidine derivatives, for example according to WO2010 / 054730; triazine derivatives, for example according to WO 2010 / 015306, WO 2007 / 063754 or WO 2008 / 056746; zinc complexes, for example according to EP 652273 or WO 2009 / 062578; dibenzofuran derivatives, for example according to WO 2009 / 148015 or WO 2015 / 169412; or bridged carbazole derivatives, for example according to US 2009 / 0136779, WO 2010 / 050778, WO 2011 / 042107 or WO 2011 / 088877. Suitable matrix materials for solution-processed OLEDs are also polymers, for example according to WO 2012 / 008550 or WO 2012 / 048778; oligomers or dendrimers, for example according to Journal of Luminescence 183 (2017), 150-158.

[0156] It is also preferred to use a plurality of different matrix materials as a mixture, in particular at least one electron-conducting matrix material and at least one hole-conducting matrix material. Preferred combinations are, for example, the use of aromatic ketones, triazine derivatives, pyrimidine derivatives, phosphine oxide derivatives or aromatic lactams together with triarylamine derivatives or carbazole derivatives as mixed matrices for the compounds of the invention. It is also preferred to use a mixture of a charge-transporting matrix material and an electrically inert matrix material (referred to as a "wide bandgap host"), which, even if it participates in charge transport, does not reach a significant extent, as described, for example, in WO 2010 / 108579 or WO 2016 / 184540. It is also preferred to use two electron-transporting matrix materials, for example a triazine derivative and a lactam derivative, for example, as described in WO 2014 / 094964.

[0157] Shown below are examples of compounds suitable as host materials for the compounds of the present invention.

[0158] Preferred bicarbazoles that can be used as host materials for the compounds of the present invention are the following structures (10) and (11):

[0159]

[0160] The symbols used are as follows:

[0161] Ar 1 are identical or different in each case and are aromatic or heteroaromatic ring systems having 5 to 40 aromatic ring atoms, preferably having 6 to 30 aromatic ring atoms, more preferably having 6 to 24 aromatic ring atoms, which may each be substituted by one or more R' groups, preferably non-aromatic R' groups;

[0162] A 1 It is NAr 1 , C(R')2, O or S, preferably C(R')2;

[0163] R' is in each case identical or different and is: H, D, F, CN, an alkyl group having 1 to 10 carbon atoms, preferably having 1 to 4 carbon atoms, or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, preferably having 6 to 30 aromatic ring atoms, more preferably having 6 to 24 aromatic ring atoms, which may be substituted by one or more substituents selected from D, F, CN or an alkyl group having 1 to 10 carbon atoms, preferably having 1 to 4 carbon atoms.

[0164] Preferred embodiments of the compounds of formula (10) and (11) are the compounds of formula (10a) and (11a) below:

[0165]

[0166] The symbols used therein have the definitions given above.

[0167] Preferred dibenzofuran derivatives are compounds of the following formula (12):

[0168]

[0169] Oxygen can also be replaced by sulfur to form dibenzothiophene, L 1 is a single bond or an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, preferably 6 to 24 aromatic ring atoms and which may also be substituted by one or more R' groups, but is preferably unsubstituted, and R' and Ar 1 has the definition given above. Two Ar bound to the same nitrogen atom 1 group, or an Ar bonded to the same nitrogen atom 1 The group and one L group can also be bonded to one another here, for example to give carbazole.

[0170] Preferred carbazole amines are the following structures (13), (14) and (15):

[0171]

[0172] Where L 1 , R' and Ar 1 has the definitions given above.

[0173] The compounds shown in the following table are examples of suitable hole-conducting matrix materials:

[0174]

[0175]

[0176]

[0177]

[0178]

[0179] Preferred triazine or pyrimidine derivatives which can be used as a mixture with the compounds of the present invention are compounds of the following formulae (16) and (17):

[0180]

[0181] Among them, Ar 1 has the definitions given above.

[0182] Particularly preferred are triazine derivatives of formula (16).

[0183] In a preferred embodiment of the present invention, Ar in formula (16) and (17) 1 are identical or different in each case and are an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, in particular 6 to 24 aromatic ring atoms, and which may be substituted by one or more R′ radicals.

[0184] Examples of suitable electron transport compounds which can be used as matrix materials together with the compounds of the present invention are the compounds shown in the following table:

[0185]

[0186]

[0187]

[0188]

[0189]

[0190]

[0191]

[0192]

[0193]

[0194]

[0195]

[0196]

[0197]

[0198]

[0199]

[0200]

[0201]

[0202]

[0203]

[0204]

[0205]

[0206]

[0207]

[0208]

[0209] Preferred cathodes are metals with low work functions, metal alloys or multilayer structures comprising various metals, such as alkaline earth metals, alkali metals, main group metals or lanthanides (e.g., Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.). Also suitable are alloys comprising alkali metals or alkaline earth metals and silver, such as alloys comprising magnesium and silver. In the case of multilayer structures, in addition to the metals mentioned, other metals with relatively high work functions, such as Ag, can also be used, in which case a combination of the metals is generally used, such as Mg / Ag, Ca / Ag or Ba / Ag. It is also preferred to introduce a thin intermediate layer of a material with a high dielectric constant between the metal cathode and the organic semiconductor. Examples of useful materials for this purpose are alkali metal fluorides or alkaline earth metal fluorides, and corresponding oxides or carbonates (e.g., LiF, Li2O, BaF2, MgO, NaF, CsF, Cs2CO3, etc.). Also useful for this purpose are organic alkali metal complexes, such as Liq (lithium quinoline). The layer thickness of this layer is preferably between 0.5 nm and 5 nm.

[0210] Preferred anodes are materials with a high work function. Preferably, the anode has a work function greater than 4.5 eV relative to vacuum. Firstly, metals with a high redox potential, such as Ag, Pt or Au, are suitable for this purpose. Secondly, metal / metal oxide electrodes (such as Al / Ni / NiO x 、Al / PtO x ). For some applications, at least one of the electrodes must be transparent or partially transparent in order to enable irradiation (O-SC) or luminescence (OLED / PLED, O-laser) of organic materials. Preferred anode materials here are conductive mixed metal oxides. Particularly preferred are indium tin oxide (ITO) or indium zinc oxide (IZO). Also preferred are conductive doped organic materials, in particular conductive doped polymers, such as PEDOT, PANI or derivatives of these polymers. It is also preferred to apply a p-doped hole transport material as a hole injection layer to the anode, in which case suitable p-type dopants are metal oxides, such as MoO3 or WO3, or (per) fluorinated electron-deficient aromatic systems. Other suitable p-type dopants are HAT-CN (hexacyanohexaazatriphenylene) or the compound NPD9 from Novaled. Such a layer simplifies hole injection in materials with a low HOMO, i.e. a HOMO that is large in magnitude.

[0211] In the other layers, generally any materials as used in the prior art for said layers can be used, and a person skilled in the art will be able to combine any of these materials with the materials of the invention in an electronic device without inventive step.

[0212] Suitable charge transport materials which can be used in the hole injection or hole transport layer or in the electron blocking layer or in the electron transport layer of the organic electroluminescent device according to the invention are, for example, the compounds disclosed in Y. Shirota et al., Chem. Rev. 2007, 107(4), 953-1010, or other materials which are used in these layers according to the prior art. Preferred hole-transport materials which can be used in the hole-transport, hole-injection or electron-blocking layer of the electroluminescent device according to the invention are indenofluorenamine derivatives (for example according to WO 06 / 122630 or WO 06 / 100896), the amine derivatives disclosed in EP 1661888, hexaazaterphenylidene derivatives (for example according to WO 01 / 049806), amine derivatives with fused aromatic systems (for example according to US Pat. No. 5,061,569), amine derivatives disclosed in WO 95 / 09147, monobenzoindenofluorenamine (for example according to WO 08 / 006449), dibenzoindenofluorenamine (for example according to WO 07 / 140847), spirobifluorenamine (for example according to WO 08 / 006449), 2012 / 034627, WO2014 / 056565), fluorenylamines (for example according to EP 2875092, EP 2875699 and EP 2875004), spirobibenzopyranamines (for example EP 2780325), and dihydroacridine derivatives (for example according to WO 2012 / 150001).

[0213] The device is structured accordingly (depending on the application), provided with contact connections and finally sealed, since the lifetime of the device is severely shortened in the presence of water and / or air.

[0214] Furthermore, an organic electroluminescent device is preferred, characterized in that one or more layers are applied by a sublimation process. In this case, the organic electroluminescent device is applied in a vacuum sublimation system at a temperature of typically less than 10 -5 mbar, preferably less than 10 -6 The material is applied by vapor deposition at an initial pressure of 10 mbar. The initial pressure can also be even lower or even higher, for example less than 10 -7 millibar.

[0215] Likewise preferred is an organic electroluminescent device as described below, characterized in that one or more layers are applied by the OVPD (organic vapor phase deposition) method or by means of carrier gas sublimation. In this case, at 10 -5The material is applied at a pressure of between mbar and 1 bar. A special example of this method is the OVJP (Organic Vapor Jet) method, in which the material is applied directly via a nozzle and thereby structured (eg MS Arnold et al., Appl. Phys. Lett. 2008, 92, 053301).

[0216] Additionally preferred is an organic electroluminescent device as described below, characterized in that one or more layers are produced from solution, for example by spin coating, or by any printing method, for example screen printing, flexographic printing, offset printing or nozzle printing, but more preferably LITI (light-induced thermal imaging, thermal transfer) or inkjet printing. For this purpose, soluble compounds are required, which are obtained, for example, by appropriate substitution.

[0217] The organic electroluminescent device can also be manufactured as a hybrid system by applying one or more layers from a solution and applying one or more other layers by vapor deposition. For example, a light-emitting layer comprising a metal complex of the invention and a matrix material can be applied from a solution, and a hole blocking layer and / or an electron transport layer can be applied thereto by vapor deposition under reduced pressure.

[0218] These processes are generally known to the person skilled in the art and can be applied by the person skilled in the art without difficulty to organic electroluminescent devices comprising compounds of the formula (1) or of the preferred embodiments detailed above.

[0219] A feature of the electronic devices, in particular the organic electroluminescent devices, of the present invention relative to the prior art is that they have a significantly improved lifetime compared to comparable structures without cyano groups on the phenyl or biphenyl substituents. At the same time, a slight improvement in efficiency and voltage is obtained.

[0220] The following examples illustrate the present invention in detail without any intention to limit the present invention. Those skilled in the art will be able to utilize the detailed information provided to manufacture other electronic devices of the present invention and thus implement the present invention within the scope of the entire claim without having to pay creative effort. Example:

[0221] Unless otherwise stated, the following syntheses were all carried out in dry solvents under a protective gas atmosphere. The metal complexes were additionally handled in the dark or under yellow light. Solvents and reagents can be purchased, for example, from Sigma-ALDRICH or ABCR. For individual compounds, the corresponding numbers or reference numbers in square brackets are related to the CAS number of the compound known from the literature. In the case where a compound can have a variety of tautomers, isomers, diastereomers and enantiomeric forms, one form is shown in a representative manner.

[0222] A: Synthesis of ligand L:

[0223] Embodiment L1:

[0224]

[0225] To a mixture of 81.8 g (100 mmol) of 2-(4-{2-[3-(2'-{[trifluoromethanesulfonyl]-4-yl}-4'-(pyridin-2-yl)-[1,1'-biphenyl]-2-yl)-5-{2-[4-(pyridin-2-yl)phenyl]ethyl}phenyl]ethyl}phenyl)pyridine [2375157-32-5], 16.2 g (110 mmol) of 4-cyanophenylboronic acid [126747-14-6], 53.1 g (250 mmol) of tripotassium phosphate, 800 ml of THF and 200 ml of water was added 1.64 g (4 mmol) of S-Phos and then 449 mg (2 mmol) of palladium (II) acetate with vigorous stirring, and the mixture was heated under reflux for 12 hours. After cooling, the aqueous phase is removed, the organic phase is concentrated substantially under reduced pressure, the residue is taken up in 500 ml of ethyl acetate and the organic phase is washed twice with 300 ml of water each time, once with a 2% aqueous solution of N-acetylcysteine, once with 300 ml of saturated sodium chloride solution and dried over magnesium sulfate. The desiccant is filtered off through a silica gel bed in the form of an ethyl acetate slurry washed thoroughly with ethyl acetate, the filtrate is concentrated to dryness and the residue is recrystallized from about 200 ml of acetonitrile at boiling. Yield: 50.2 g (65 mmol), 65%; purity: by 1 H NMR determined to be approximately 98%.

[0226] The following compounds can be prepared similarly:

[0227]

[0228]

[0229]

[0230]

[0231]

[0232]

[0233]

[0234] C: Preparation of metal complexes

[0235] Embodiment Ir (L1):

[0236]

[0237] A mixture of 7.71 g (10 mmol) of ligand L1, 4.90 g (10 mmol) of iridium (III) triacetylacetonate [15635-87-7] and 120 g of hydroquinone [123-31-9] was first charged into a 1000 ml two-necked round-bottom flask with a glass-sheathed magnetic bar. The flask was equipped with a water separator (for media with a density lower than that of water) and an air condenser with an argon seal. The flask was placed in a metal heating bath. The apparatus was purged from the top with argon for 15 minutes through an argon seal system, allowing argon to flow out of the side neck of the two-necked flask. A Pt-100 thermocouple with a glass sheath was introduced into the flask through the side neck of the two-necked flask and its end was placed just above the magnetic stirrer bar. The apparatus was then insulated with several loose rolls of domestic aluminum foil, which extended to the middle of the riser of the water separator. The apparatus was then rapidly heated to 240°C to 245°C with a heated laboratory stirrer system, measured with a Pt-100 temperature sensor immersed in the molten stirred reaction mixture. The reaction mixture was maintained at 240°C to 245°C over the next 1 hour, during which a small amount of condensate was distilled off and collected in a water separator. After 1 hour, the mixture was allowed to cool to about 190°C, the heating bath was removed, and then 100 ml of ethylene glycol was added dropwise. After cooling to 100°C, 400 ml of methanol was slowly added dropwise. The yellow suspension thus obtained was filtered through a double-ended glass frit, and the yellow solid was washed three times with 50 ml of methanol and then dried under reduced pressure. The solid thus obtained was dissolved in 200 ml of dichloromethane and filtered through 600 g of silica gel (column diameter of about 10 cm) in the form of a dichloromethane slurry under light and air protection, leaving the dark component at the beginning. The core fraction was separated and concentrated on a rotary evaporator while continuously adding MeOH dropwise until crystallization. After filtration with suction, washing with a small amount of MeOH and drying under reduced pressure, the yellow product is further purified by continuous hot extraction with dichloromethane / isopropanol 1:1 (vv) under careful exclusion of air and light (initial amount in each case about 200 ml, extraction sleeve: standard Soxhlet sleeve made of cellulose from Whatman). The loss into the mother liquor can be adjusted by the ratio of dichloromethane (low boiler and good solubilizer): isopropanol or acetonitrile (high boiler and poor solubilizer). It should generally be 3% to 6% by weight of the amount used. Hot extraction can also be done with other solvents such as toluene, xylene, ethyl acetate, butyl acetate, etc. Finally, the product is obtained at a pH of about 10 -6 Fractional sublimation was carried out at a high vacuum of mbar and a T of about 330° C. to 430° C. Yield: 4.91 g (5.1 mmol), 51%; purity: >99.9% as determined by HPLC.

[0238] The metal complex is usually obtained as a 1:1 mixture of Λ and Δ isomers / enantiomers. The images of the complexes cited below usually show only one isomer. If a ligand with three different subligands is used, or a chiral ligand as a racemate is used, the metal complex derived is obtained as a diastereomeric mixture. They can be separated by fractional crystallization or by chromatography, for example, with an automatic column system (CombiFlash, from A.Semrau). If a chiral ligand is used in an enantiomer-pure form, the metal complex derived is obtained as a diastereomeric mixture, which is separated by fractional crystallization or chromatography to obtain a pure enantiomer. The separated diastereomer or enantiomer can be further purified as described above, for example by hot extraction.

[0239] The following compounds can be prepared similarly:

[0240]

[0241]

[0242]

[0243]

[0244]

[0245]

[0246]

[0247] B: Functionalization of metal complexes

[0248] A) Deuteration of methyl / methylene groups on pyridine ligands:

[0249] 1 mmol of the pure complex (purity>99.9%) having x methyl / methylene groups with x=1-6 is dissolved in 50 ml of DMSO-d6 (deuteration level>99.8%) by heating to about 180° C. The solution is stirred for 5 minutes at 180° C. The solution is cooled to 80° C. and a mixture of 5 ml of methanol-d1 (deuteration level>99.8%) and 10 ml of DMSO-d6 (deuteration level>99.8%) in which 0.3 mmol of sodium hydride has been dissolved is added rapidly to the solution with good stirring. The clear yellow / orange solution is stirred for a further 30 minutes at 80°C for complexes with a methyl / methylene group in the para position of the pyridine nitrogen or for a further 6 hours for complexes with a methyl / methylene group in the meta position of the pyridine nitrogen, the mixture is then cooled with the aid of a cold water bath, 20 ml of 1N DCL in D2O are added dropwise starting from about 60°C, the mixture is cooled to room temperature and stirred for a further 5 hours, the solid is filtered off with suction, washed three times with 10 ml of H2O / MeOH (1:1, vv) and then three times with 10 ml of MeOH each time and dried under reduced pressure. The solid is dissolved in DCM, the solution is filtered through silica gel and the filtrate is concentrated under reduced pressure with dropwise addition of MeOH, resulting in crystallization. Finally, fractional sublimation is carried out, which is carried out as described in "C: Preparation of metal complexes, variant A". The yield is generally 80% to 90%, and the deuteration level is >95%.

[0250] In a similar manner, the following deuterated complexes can be prepared:

[0251]

[0252]

[0253] Example: Fabrication of OLEDs

[0254] 1) Vacuum processed devices:

[0255] The OLEDs according to the invention and the OLEDs of the prior art are produced by the general method according to WO 2004 / 058911, which is adjusted to the circumstances described there (variation of layer thicknesses, materials used).

[0256] Clean glass plates (cleaned in a Miele laboratory glass washer, Merck Extran cleaning agent) coated with 50 nm thick structured ITO (indium tin oxide) were baked at 250° C. for 15 minutes under nitrogen. The pre-cleaned ITO substrate was subjected to a dual gas plasma treatment (oxygen followed by argon) to finally clean the ITO surface and adjust the ITO work function. These coated glass plates formed the substrate for applying the OLED. All materials were applied by thermal vacuum deposition. In this case, the luminescent layer always consists of at least one matrix material (host material) and a luminescent dopant (luminophore), which is added to the matrix material in a specific volume ratio by co-evaporation. Detailed information given in the form of M1:M2:Ir luminophore (29.5%:58.5%:12%) means here that the material M1 is present in the layer in a volume ratio of 29%, M2 is present in the layer in a volume ratio of 58.5%, and the Ir luminophore is present in the layer in a volume ratio of 12%. Similarly, the electron transport layer also consists of a mixture of two materials.

[0257] The OLED basically has the following layer structure: ITO substrate / hole injection layer 1 (HIL1) composed of HTM1 doped with 5% NDP-9 (commercially available from Novaled), 20nm / hole transport layer 1 (HTL1) composed of HTM1, 40nm / hole transport layer 2 (HTL2), 20nm / light-emitting layer (EML), see Table 1 / hole blocking layer (HBL), see Table 1 / electron transport layer (ETL), see Table 1 / electron injection layer (EIL), see Table 1 / cathode, formed of an aluminum layer with a thickness of 100nm. Table 3 shows the materials used to manufacture the OLED.

[0258] OLEDs are characterized in a standard manner. For this purpose, the electroluminescence spectrum, the current-voltage-luminance characteristic (IUL characteristic) showing Lambertian emission properties, the current efficiency (measured in cd / A), the power efficiency (measured in lm / W) and the external quantum efficiency (EQE, measured in %) as a function of luminance, and the lifetime are determined. The electroluminescence spectrum is measured at 1000 cd / m 2 The luminance of the color is determined at 10000 cd / m and used to calculate the CIE 1931 x and y color coordinates. The lifespan LD90 is defined as the brightness of the color at 10000 cd / m 2 The lifetime value is the time it takes for the brightness to drop to 90% of the initial brightness at a starting brightness of 1.5 %. The OLED can also be initially operated at a different starting brightness. The lifetime value can then be converted to a value at a different starting brightness using a conversion formula known to those skilled in the art.

[0259] Use of the compounds of the present invention as luminescent materials in phosphorescent OLEDs

[0260] One use of the compounds according to the invention is as phosphorescent emitter material in the light-emitting layer of an OLED. The Ir compounds of Table 3 were used as comparison according to the prior art. The results for the OLEDs are summarized in Table 2.

[0261] From the results, it can be seen that when the compounds of the present invention are used as emitters in OLEDs, they lead to a slight improvement in efficiency and voltage and at the same time a significant improvement in lifetime, for example, compared with the Ir-Ref.1 complex according to the prior art (which has the same structure as Ir(L100) but does not contain a cyano group on the biphenyl substituent), in the case of the complex Ir(L100) of the present invention, the lifetime is improved by 60%.

[0262] Table 1: Structure of OLED

[0263]

[0264]

[0265] Table 2: Results for vacuum processed OLEDs

[0266] (Efficiency, EQE, voltage, 1000cd / m 2 CIE under 1000cd / m 2 Lifespan under LD90)

[0267]

[0268] Table 3: Structural formula of materials used

[0269]

[0270] .

Claims

1. A compound of formula (I), Ir(L) formula (1) The ligand L has the structure of the following formula (2): The ligand L is coordinated to the iridium atom via the position indicated by *, and hydrogen atoms not explicitly shown therein may also be replaced by D, and the symbols and notations used therein are as follows: R is in each case identical or different and is: H, D, F, a straight-chain alkyl radical having 1 to 10 carbon atoms or a branched or cyclic alkyl radical having 3 to 10 carbon atoms, where the alkyl radical may in each case also be deuterated; R 1 are in each case identical or different and are: H, D, a straight-chain alkyl radical having 1 to 10 carbon atoms or a branched or cyclic alkyl radical having 3 to 10 carbon atoms, whereby the alkyl radical may in each case also be deuterated; R 2 are in each case identical or different and are: H, D, a straight-chain alkyl radical having 1 to 10 carbon atoms, a branched or cyclic alkyl radical having 3 to 10 carbon atoms, where the alkyl radicals may in each case also be deuterated, m is 1, 2 or 3; n is in each case identical or different and is 0, 1, 2 or 3; o is 1; p is 0; q is 0, 1, or 2; r is 0, 1 or 2.

2. The compound according to claim 1, characterized in that When m = 1, the ligand L is a structure of formula (3a), when m = 2, the ligand L is a structure of formula (3b) or (3c), and when m = 3, the ligand L is a structure of formula (3d) or (3e): Hydrogen atoms not explicitly shown there may also be replaced by D, and the symbols and indices have the meanings given in claim 1.

3. The compound according to claim 1 or 2, characterized in that The ligand L has the structure of formula (7): Hydrogen atoms not explicitly shown there may also be replaced by D, and the symbols and indices have the meanings given in claim 1.

4. The compound according to claim 1 or 2, characterized in that The substituents are as follows: R is identical or different in each case and is selected from: D, a straight-chain alkyl radical having 1 to 6 carbon atoms or a branched or cyclic alkyl radical having 3 to 6 carbon atoms, wherein each of the alkyl radicals may also be deuterated; R 1 are identical or different in each case and are selected from: D, a straight-chain alkyl radical having 1 to 6 carbon atoms or a branched or cyclic alkyl radical having 3 to 6 carbon atoms, wherein each of the alkyl radicals may also be deuterated; R 2 are identical or different in each case and are selected from: D, a straight-chain alkyl radical having 1 to 6 carbon atoms or a branched or cyclic alkyl radical having 3 to 6 carbon atoms, where each of the alkyl radicals may also be deuterated.

5. The compound according to claim 1 or 2, characterized in that The symbols and markings are as follows: R is identical or different in each case and is selected from: D, a straight-chain alkyl group having 1 to 4 carbon atoms or a branched alkyl group having 3 or 4 carbon atoms, wherein each of the alkyl groups may also be deuterated; R 1 are identical or different in each case and are selected from: D, a straight-chain alkyl group having 1 to 4 carbon atoms or a branched alkyl group having 3 or 4 carbon atoms, wherein each of the alkyl groups may also be deuterated; R 2 are identical or different in each case and are selected from: D, a straight-chain alkyl group having 1 to 4 carbon atoms or a branched alkyl group having 3 or 4 carbon atoms, wherein each of the alkyl groups may also be deuterated; m is 1 or 2; n is in each case identical or different and is 0, 1 or 2; o is 1; p is 0; q is 0 or 1; r is 0 or 1.

6. The compound according to claim 1 or 2, characterized in that The ligand L has the structure of formula (9): The hydrogen atoms not explicitly shown can also be replaced by D, R, R 1 and R 2 Having the definitions given in claim 1, q = 0 or 1 and r = 0 or 1.

7. A process for preparing a compound according to any one of claims 1 to 6, said process being carried out in the following manner: reacting the free ligand L with an iridium alkoxide of formula (Ir-1), with an iridium keto-ketonate of formula (Ir-2), with an iridium halide of formula (Ir-3) or with an iridium carboxylate of formula (Ir-4), or with an iridium compound simultaneously carrying an alkoxy anion and / or a halide anion and / or a hydroxyl group and / or a keto-keto anion group: wherein R has the definition given in claim 1, Hal = F, Cl, Br or I, and the iridium reactant may also be in the form of a corresponding hydrate.

8. A formulation comprising at least one compound according to any one of claims 1 to 6 and at least one solvent.

9. Use of a compound according to any one of claims 1 to 6 in an electronic device. 10 . An electronic device comprising at least one compound according to claim 1 .

11. The electronic device according to claim 10, wherein the electronic device is an organic electroluminescent device, characterized in that The compound according to any one of claims 1 to 6 is used as emitting compound in one or more emitting layers.

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