Metal complexes

Abstract

To provide a metal complex suitable for use as a light-emitting material in an organic electroluminescent device.SOLUTION: The present invention relates to metal complexes and electronic devices, in particular organic electroluminescent devices, containing the metal complexes.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to metal complexes suitable for use as emitters in organic electroluminescent devices. [Background technology]

[0002] In organic electroluminescent devices (OLEDs) using organic semiconductors as functional materials, the emitting materials used are often organometallic complexes that exhibit phosphorescence rather than fluorescence. In general, there is still a need for improvement in OLEDs that exhibit triplet emission, especially with regard to efficiency, operating voltage and lifetime. The triplet emitters used are in particular iridium and platinum complexes. The iridium complexes used are in particular bis- and tris-ortho-metallated complexes with aromatic ligands, where the ligands are bonded to the metal via negatively charged carbon atoms and uncharged nitrogen atoms. Examples of such complexes include imidazoisoquinoline complexes (e.g. according to WO2010 / 086089 or WO2011 / 157339) or imidazophenanthridine complexes (e.g. according to US2012 / 0153816 or US2015 / 0295189), in which the ligands are coordinated to iridium via one six-membered ring and one five-membered ring in each case. Summary of the Invention [Problem to be solved by the invention]

[0003] It is an object of the present invention to provide novel metal complexes suitable as emitters for use in OLEDs, leading in particular to emission colours in the green-red range and to good efficiency and lifetime. [Means for solving the problem]

[0004] It has surprisingly been found that certain metal chelate complexes, disclosed in detail below, are highly suitable for use in organic electroluminescent devices, and the present invention therefore relates to these metal complexes, and to organic electroluminescent devices comprising these complexes.

[0005] The present invention relates to a compound of formula (1), M(L) n (L') m Formula (1) The substructure M(L) of formula (2) n Provide something that includes. [ka] where the symbols and subscripts used are as follows: M is iridium or platinum; D is C or N, where one D is C and the other D is N; X is identical or different at each occurrence and is CR or N; R is the same or different at each occurrence and is H, D, F, Cl, Br, I, N(R 1 )2, CN, NO2, OR 1 , S.R. 1 , COOR 1 , C(=O)N(R 1 )2, Si(R 1 )3, B(OR 1 )2, C(=O)R 1 , P(=O)(R 1 )2, S(=O)R 1 , S(=O)2R 1 , OSO2R 1 , a linear alkyl group having 1 to 20 carbon atoms, or an alkenyl or alkynyl group having 2 to 20 carbon atoms, or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group is in each case composed of one or more R 1 radical, where one or more non-adjacent CH groups are Si(R 1)2, C=O, NR 1 , O, S or CONR 1 or having 5 to 60 aromatic ring atoms, preferably 5 to 40 aromatic ring atoms, in each case one or more R 1 an aromatic or heteroaromatic ring system, optionally substituted by a radical; at the same time, two R radicals together may form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system; R 1 are the same or different for each occurrence and are H, D, F, Cl, Br, I, N(R 2 )2, CN, NO2, OR 2 , S.R. 2 , Si(R 2 )3, B(OR 2 )2, C(=O)R 2 , P(=O)(R 2 )2, S(=O)R 2 , S(=O)2R 2 , OSO2R 2 , a linear alkyl group having 1 to 20 carbon atoms, an alkenyl or alkynyl group having 2 to 20 carbon atoms, or a branched or cyclic alkyl group having 3 to 20 carbon atoms (wherein each of the alkyl, alkenyl, or alkynyl groups is one or more of R 2 radical, where one or more non-adjacent CH groups are Si(R 2 )2, C=O, NR 2 , O, S or CONR 2 and in which one or more hydrogen atoms in the alkyl, alkenyl or alkynyl group may be replaced by D, F, Cl, Br, I or CN), or having 5 to 40 aromatic ring atoms, in each case one or more R 2 an aromatic or heteroaromatic ring system, optionally substituted by radicals; 1 the radicals together may form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system; R 2is the same or different at each occurrence and is H, D, F, CN or an aliphatic, aromatic or heteroaromatic organic radical having 1 to 20 carbon atoms, in particular a hydrocarbyl radical, in which one or more hydrogen atoms may be replaced by F; L' is the same or different at each occurrence and is a ligand; n is 1, 2 or 3; m is 0, 1, 2, 3 or 4; At the same time, it is also possible for two or more ligands L to be linked together or for L to be linked to L' by a single bond or a divalent or trivalent bridge to form a tridentate, tetradentate, pentadentate or hexadentate ligand system.

[0006] In the sense of the present invention, an aryl group contains 6 to 40 carbon atoms. In the sense of the present invention, a heteroaryl group contains 2 to 40 carbon atoms and at least one heteroatom, with the proviso that the sum of carbon atoms and heteroatoms is at least 5. The heteroatoms are preferably selected from N, O and / or S. Preferably, a heteroaryl group contains 1, 2 or 3 heteroatoms, not more than 1 being selected from O and S. An aryl or heteroaryl group here is understood to mean either a single aromatic ring, i.e. benzene, or a single heteroaromatic ring, such as pyridine, pyrimidine, thiophene, etc., or a fused, aryl or heteroaryl group, such as naphthalene, anthracene, phenanthrene, quinoline, isoquinoline, etc.

[0007] An aromatic ring system, within the meaning of the present invention, comprises 6 to 60 carbon atoms in the ring system. A heteroaromatic ring system, within the meaning of the present invention, comprises 1 to 60 carbon atoms in the ring system and at least one heteroatom, provided that the sum of carbon atoms and heteroatoms is at least 5. The heteroatom is preferably selected from N, O and / or S. An aromatic or heteroaromatic ring system, within the meaning of the present invention, is understood to mean not only systems which necessarily contain aryl or heteroaryl groups, but also systems in which several aryl or heteroaryl groups can be linked by non-aromatic units (preferably less than 10% of atoms other than H), such as carbon, nitrogen or oxygen atoms or carbonyl groups. For example, systems such as 9,9'-spirobifluorene, 9,9-diarylfluorene, triarylamines, diaryl ethers, stilbenes, etc., are also considered as aromatic ring systems within the meaning of the present invention, as are systems in which two or more aryl groups are linked, for example by linear or cyclic alkyl groups or by silyl groups. Additionally, systems in which two or more aryl or heteroaryl groups are directly bonded to one another (eg, biphenyl or terphenyl) are also considered aromatic or heteroaromatic ring systems.

[0008] Cyclic alkyl, alkoxy or thioalkoxy groups are understood in the sense of the present invention to mean monocyclic, bicyclic or polycyclic groups. When two or more substituents together form an aliphatic ring system, in the sense of the present invention the term "aliphatic ring system" also includes heteroaliphatic ring systems.

[0009] In the sense of the present invention, C1-C 40Alkyl groups (wherein each hydrogen atom or CH2 group may be replaced by the above groups) are, for example, methyl, ethyl, n-propyl, i-propyl, cyclopropyl, n-butyl, i-butyl, s-butyl, t-butyl, cyclobutyl, 2-methylbutyl, n-pentyl, s-pentyl, t-pentyl, 2-pentyl, neopentyl, cyclopentyl, n-hexyl, s-hexyl, t-hexyl, 2-hexyl, 3-hexyl, neohexyl, cyclohexyl, 1-methylcyclohexyl, 2 ... Clopentyl, 2-methylpentyl, n-heptyl, 2-heptyl, 3-heptyl, 4-heptyl, cycloheptyl, 1-methylcyclohexyl, n-octyl, 2-ethylhexyl, cyclooctyl, 1-bicyclo[2.2.2]octyl, 2-bicyclo[2.2.2]octyl, 2-(2,6-dimethyl)octyl, 3-(3,7-dimethyl)octyl, adamantyl, trifluoromethyl, pentafluoroethyl, 2,2,2-trifluoroethyl, 1,1-dimethyl-n-hexa-1 -yl, 1,1-dimethyl-n-hept-1-yl, 1,1-dimethyl-n-oct-1-yl, 1,1-dimethyl-n-dec-1-yl, 1,1-dimethyl-n-dodec-1-yl, 1,1-dimethyl-n-tetradec-1-yl, 1,1-dimethyl-n-hexadec-1-yl, 1,1-dimethyl-n-octadec-1-yl, 1,1-diethyl-n-hex-1-yl, 1,1-diethyl-n-hept-1-yl, 1,1-diethyl-n-oct-1-yl, 1,1-diethyl-n- Dec-1-yl, 1,1-diethyl-n-dodec-1-yl, 1,1-diethyl-n-tetradec-1-yl, 1,1-diethyl-n-hexadec-1-yl, 1,1-diethyl-n-octadec-1-yl, 1-(n-propyl)cyclohex-1-yl, 1-(n-butyl)cyclohex-1-yl, 1-(n-hexyl)cyclohex-1-yl, 1-(n-octyl)cyclohex-1-yl- and 1-(n-decyl)cyclohex-1-yl radicals. Alkenyl groups are understood to mean, for example, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl or cyclooctadienyl.An alkynyl group is understood to mean, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl or octynyl. C1-C. 40 An alkoxy group is taken to mean, for example, methoxy, trifluoromethoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy or 2-methylbutoxy.

[0010] Aromatic or heteroaromatic ring systems having 5 to 60 aromatic ring atoms, which in each case may be substituted by the abovementioned radicals and which may be linked to the aromatic or heteroaromatic ring system via any position, are, for example, benzene, naphthalene, anthracene, benzoanthracene, phenanthrene, benzophenanthrene, pyrene, chrysene, perylene, fluoranthene, benzofluoranthene, naphthacene, pentacene, benzopyrene, biphenyl, biphenylene, terphenyl, terphenylene, fluorene, spirobifluorene, diphenylene, Hydrophenanthrene, dihydropyrene, tetrahydropyrene, cis- or trans-indenofluorene, cis- or trans-monobenzoindenofluorene, cis- or trans-dibenzoindenofluorene, truxene, isotruxene, spirotruxene, spiroisotruxene, furan, benzofuran, isobenzofuran, dibenzofuran, thiophene, benzothiophene, isobenzothiophene, dibenzothiophene, pyrrole, indole, isoindole, carbazole, indolocarbazole, indenocarbazole , pyridine, quinoline, isoquinoline, acridine, phenanthridine, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthoimidazole, phenanthreimidazole, pyridimidazole, pyrazineimidazole, quinoxalineimidazole, oxazole, benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, 1,2-thiazole, 1,3 -Thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine, benzopyrimidine, quinoxaline, 1,5-diazaanthracene, 2,7-diazapyrene, 2,3-diazapyrene, 1,6-diazapyrene, 1,8-diazapyrene, 4,5-diazapyrene, 4,5,9,10-tetraazapyrylene, pyrazine, phenazine, phenoxazine, phenothiazine, fluorubine, naphthyridine, azacarbazole, benzocarboline, phenanthroline, 1,2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,It is understood to mean radicals derived from 3-oxadiazole, 1,2,4-oxadiazole, 1,2,5-oxadiazole, 1,3,4-oxadiazole, 1,2,3-thiadiazole, 1,2,4-thiadiazole, 1,2,5-thiadiazole, 1,3,4-thiadiazole, 1,3,5-triazine, 1,2,4-triazine, 1,2,3-triazine, tetrazole, 1,2,4,5-tetrazine, 1,2,3,4-tetrazine, 1,2,3,5-tetrazine, purine, pteridine, indolizine and benzothiadiazole.

[0011] The expression that two or more radicals may together form an aliphatic ring is understood in the context of this specification to mean, inter alia, that the two radicals are linked to each other by a chemical bond with the formal deletion of two hydrogen atoms, as shown by the following scheme: [ka]

[0012] The formation of fused aromatic or heteroaromatic groups is also possible and is illustrated by the following scheme: [ka]

[0013] Furthermore, however, the above expression is understood to mean that if one of the two radicals is hydrogen, the second radical is attached to the bonded position of the hydrogen atom to form a ring, which is illustrated by the following scheme: [ka]

[0014] Preferred compounds of formula (1) are characterized in that they are uncharged, i.e. electrically neutral, which is achieved in a simple manner by selecting the charges of the ligands L and L' so as to complement the charge of the complexed metal atom M.

[0015] In the complex of formula (1), the subscripts n and m are chosen so that the sum of the coordination numbers of the metal M depends on the metal and usually corresponds to the coordination number of this metal. For iridium(III), the coordination number is 6, for platinum(II), the coordination number is 4.

[0016] In one embodiment of the invention, M=iridium(III) and the index n is 1, 2 or 3, preferably 2 or 3. When the index n is 1, four monodentate, or two bidentate, or one bidentate and two monodentate, or one tridentate and one monodentate, or one tetradentate ligand L', preferably two bidentate ligands L', are coordinated to the iridium. When the index n is 2, one bidentate or two monodentate ligands L', preferably one bidentate ligand L', are also coordinated to the iridium. When the index n=3, the index m=0.

[0017] In a further embodiment of the invention, M=platinum(II) and the index n is 1 or 2. When the index n is 1, one bidentate or two monodentate ligands L′, preferably one bidentate ligand L′, are also coordinated to the platinum M. When n=2, m=0.

[0018] Two structures arise as formula (2) when the D groups are C and N. These are shown below by formulas (3) and (4). [ka] Here, the symbols and indices used have the meanings given above.

[0019] In a preferred embodiment of the present invention, up to one X, if present, is N and the other X groups are CR. More preferably, the symbol X in two six-membered rings is CR, or one symbol X in a six-membered ring coordinated via a carbon atom is N and the other symbol X in two six-membered rings is CR and exactly one symbol X in a five-membered ring is N. Preferred embodiments of formula (3) are structures of the following formulae (3a) to (3f), and preferred embodiments of formula (4) are structures of the following formulae (4a) to (4f). [ka] Here, the symbols and indices used have the meanings given above.

[0020] Preferably, the structure of formula (2) is any of the structures of the following formulae (3a-1) to (4f-1). [ka] wherein the symbols and subscripts used have the meanings given above, and R' has the same meaning as R, where at least one substituent R' is not H or D.

[0021] The structure of formula (3) or (3a) to (3c) is preferred, and the structure of formula (3a) is particularly preferred.

[0022] Substituents and the formation of rings by the substituents can affect the triplet energy and hence the emission color of the unit of formula (2). For example, when two substituents R in the five-membered ring of formulas (3a), (3c), (3d), (4a), (4c) and (4d) together form a fused benzene ring, this results in IrL n The triplet energy of the unit is reduced, thereby n This results in a bathochromic shift of the emission of the units.

[0023] As noted above, adjacent R radicals may together form an aliphatic, aromatic or heteroaromatic ring system. In one aspect of the invention, two adjacent R radicals on a five-membered ring together form one or more R 1It forms a fused benzo group which may be substituted by a radical. Preferred forms are structures of formulae (3a-2) to (4a-6). [ka] [ka] [ka] Here, the symbols and indices used have the meanings given above.

[0024] Preferred R radicals are the same or different at each occurrence and are H, D, F, Br, I, N(R 1 )2, CN, Si(R 1 )3, B(OR 1 2. A linear alkyl group having 1 to 10 carbon atoms, an alkenyl group having 2 to 10 carbon atoms, or a branched or cyclic alkyl group having 3 to 10 carbon atoms (each of these groups may have one or more R 1 radicals, in which one or more hydrogen atoms may be replaced by D or F), or having 5 to 24 aromatic ring atoms, in each case one or more R 1 at the same time, two preferably adjacent R radicals may together form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system. More preferably, these R radicals are the same or different at each occurrence and are selected from the group consisting of H, D, F, N(R 1 CN, a linear alkyl group having 1 to 6 carbon atoms or an alkenyl group having 2 to 6 carbon atoms or a branched or cyclic alkyl group having 3 to 10 carbon atoms, in which one or more hydrogen atoms may be replaced by D or F, or a cyclic alkyl group having 6 to 13 aromatic ring atoms, in each case one or more R 1at the same time, two adjacent R radicals together may form an aliphatic or aromatic ring system.

[0025] Preferred R 1 The radicals may be the same or different at each occurrence and may be H, D, F, CN, a straight chain alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 10 carbon atoms, each of which may be one or more R 2 radicals, in which one or more hydrogen atoms may be replaced by F), or having 5 to 24 aromatic ring atoms, in each case one or more R 2 an aromatic or heteroaromatic ring system, optionally substituted by a radical; at the same time, two or more adjacent R 1 The radicals together may form an aliphatic, aromatic or heteroaromatic ring system. Particularly preferred R 1 The radicals may be the same or different at each occurrence and may be H, D, F, a linear alkyl group having 1 to 4 carbon atoms or a branched or cyclic alkyl group having 3 to 6 carbon atoms, or an aromatic or heteroaromatic ring system having 6 to 13 aromatic ring atoms, each of which may be one or more of R 2 radicals, but preferably unsubstituted; and at the same time, two or more adjacent R 1 The radicals together may form an aliphatic or aromatic ring system.

[0026] Preferred R 2 The radical is selected from the group consisting of H, D, F, CN, an alkyl group having 1 to 6 carbon atoms, or an aromatic ring system having 6 to 12 carbon atoms.

[0027] In a further embodiment of the invention, two adjacent R radicals together form an aliphatic ring system. In the case of adjacent radicals, this can be one or both of the five-membered rings and / or the five-membered ring. Preferred aliphatic ring systems are selected from the structures of the following formulae (5) to (11): [ka] Here, R 1 and R 2 has the meaning given above, the dotted bond indicates the connection of two carbon atoms in the ligand, and further: G has 1, 2 or 3 carbon atoms and is one or more R 2 an alkylene group optionally substituted by a radical, -CR 2 =CR 2 - or 5 or 6 aromatic ring atoms and at least one R 2 an ortho-linked arylene or heteroarylene group optionally substituted by a radical; R 3 are identical or different for each occurrence, F, OR 2 , a linear alkyl group having 1 to 10 carbon atoms, a branched or cyclic alkyl group having 3 to 10 carbon atoms (wherein the alkyl group in each case is one or more R 2 radical, where one or more non-adjacent CH groups are R 2 C=CR 2 , C≡C, Si(R 2 )2, C=O, NR 2 , O, S or CONR 2 or having 5 or 6 aromatic ring atoms and in each case one or more R 2 an aryl or heteroaryl group, optionally substituted by a radical; and at the same time, two R 3 The radicals may form an aliphatic ring system, thus forming a spiro system; 3 is adjacent to R or R 1 Together with the radicals they may form an aliphatic ring system.

[0028] In the above structures of formulae (5) to (11) above and further forms of these structures identified as preferred, the double bond is a formal representation between two carbon atoms. This is a simplification of the chemical structure in which the two carbon atoms are incorporated into an aromatic or heteroaromatic ring system and the bond between these two carbon atoms is formally between the bond order of a double bond of the bond order of a single bond.

[0029] Preferred forms of the groups of formulae (5) to (11) are disclosed in patent documents WO2014 / 023377, WO2015 / 104045 and WO2015 / 117718.

[0030] As mentioned above, in the compounds of the invention, instead of one radical R, a bridging unit may be present, which is linked to one or more further ligands L or L'. In a preferred embodiment of the invention, instead of one of the radicals R present, a bridging unit is present in the ortho or meta position of one of the coordination atoms of the coordination hexagon, in particular in the meta position of the coordination atom, so that the ligand has a tridentate or polydentate or polypodal character. It is also possible for two to be present as such bridging units. This forms a macrocyclic ligand or a cryptate.

[0031] Preferred structures having a polydentate ligand are metal complexes of the following formulae (12) to (15). [ka] The symbols and subscripts used herein have the meanings given above. L' is preferably a bidentate antimetabolite, in particular a monoanionic bidentate antimetabolite coordinated via a carbon atom and a nitrogen atom.

[0032] Here, V in the structures of formulae (14) and (15) is preferably BR 1 , B(R 1 )2 - , C(R 1 )2, C(=O), Si(R1 )2, NR 1 , P.R. 1 , P(R 1 )2 + , P(=O)(R 1 ), P(=S)(R 1 ), O, S, Se, or one of the units of formulae (16) to (25). [ka] where the dotted bond indicates a bond to an ancillary ligand L or L′, respectively, Q is the same or different at each occurrence, and C(R 1 )2, N(R 1 ), O or S, and Z is the same or different at each occurrence and is a single bond, O, S, S(=O), S(=O)2, NR 1 , P.R. 1 , P(=O)R 1 , C(R 1 )2, C(=O), C(=NR 1 ), C(=C(R 1 )2), Si(R 1 )2 and BR 1 The further symbols used have the meanings given above and are selected from the group consisting of:

[0033] Additionally, V in the structures of formulas (12) and (13) is preferably a group of formula (26) below, where the dotted bond indicates the attachment point of the ancillary ligands L and L'. [ka] where: X 1 is the same or different at each occurrence and is CR or N; A is the same or different at each occurrence and is CR-CR, CR-O, CR-NR, C(=O)-O, C(=O)-NR or a group of formula (27): [ka] where in each case the dotted bond indicates the point of attachment of the bidentate ancillary ligand L or L' to the structure, the * indicates the point of attachment to the central trivalent aryl or heteroaryl group of the unit of formula (27), and X 2 is the same or different at each occurrence and is either CR or N.

[0034] X 2 Preferred substituents for the group of formula (27) when =CR are selected from the R substituents described above.

[0035] In a preferred embodiment of the invention, A is identical or different at each occurrence and is CR2-CR2 or a group of formula (27), preferably in the following form: - all three A groups are the same group of formula (27); - two A groups are identical groups of formula (27) and the third A group is CR2-CR2; - one A group is of formula (27) and the other two A groups are identical groups CR2-CR2; or - all three A groups are identical CR2-CR2 groups.

[0036] Here, "the same group of formula (27)" means that all of these groups have the same basic structure and the same substituents. Furthermore, "the same CR2-CR2 group" means that all of these groups have the same substituents.

[0037] When A is CR2-CR2, R is preferably identical or different at each occurrence and is H or D, more preferably H.

[0038] The group of formula (27) is an aromatic or heteroaromatic six-membered ring. In a preferred embodiment of the invention, the group of formula (27) contains no more than one heteroatom in the aryl or heteroaryl group. This does not mean that any of the substituents attached to this group cannot contain heteroatoms. Furthermore, this definition does not mean that ring formation by the substituents does not result in fused aromatic or heteroaromatic structures (e.g., naphthalene, benzimidazole, etc.). The group of formula (27) is preferably selected from benzene, pyridine, pyrimidine, pyrazine and pyridazine.

[0039] Preferred embodiments of the group of formula (27) are structures of the following formulae (28) to (35). [ka] Here, the symbols used have the meanings given above.

[0040] Particularly preferred are the optionally substituted radicals of the formulae (28) to (32). Very particular preference is given to ortho-phenylene, i.e. the radical of formula (28).

[0041] At the same time, as described above in the details of the substituents, adjacent substituents can also be taken together to form a ring, thereby forming a fused structure containing fused aryl and heteroaryl groups (e.g., naphthalene, quinoline, benzimidazole, carbazole, dibenzofuran or dibenzothiophene).

[0042] Preferred embodiments of the group of formula (26) are structures of the following formulae (36) to (39). [ka] Here, the symbols used have the meanings given above.

[0043] More preferably, all substituents R of the central ring of formulae (36) to (39) are H, and therefore the structures are preferably selected from formulae (36a) to (39a). [ka] Here, the symbols used have the meanings given above.

[0044] More preferably, the groups of formulae (36) to (39) are selected from the structures of formulae (36b) to (39b) below. [ka] wherein R is the same or different at each occurrence and is H or D, preferably H.

[0045] Preferred ligands L' appearing in formula (1) are shown below: Ligands L' are selected when they are attached to L via a bridging V unit.

[0046] The ligands L' are preferably uncharged, monoanionic, dianionic or trianionic ligands, more preferably uncharged or monoanionic ligands, in particular monoanionic ligands. They may be monodentate, bidentate, tridentate or tetradentate, preferably bidentate, i.e. preferably have two coordination sites. As mentioned above, the ligands L' may be linked to L via a bridging V group. More preferably, the ligands L' are bidentate and monoanionic.

[0047] Preferred uncharged monodentate ligands L' are carbon monoxide, nitric oxide, alkyl cyanides such as acetonitrile, aryl cyanides such as benzonitrile, alkyl isocyanides such as methyl isonitrile, aryl isocyanides such as benzoisonitrile, amines such as trimethylamine, triethylamine, morpholine, phosphines, in particular halophosphines, trialkylphosphines, triarylphosphines or alkylarylphosphines such as trifluorophosphine, trimethylphosphine, tricyclohexylphosphine, tri-tert-butylphosphine, triphenylphosphine, tris(pentafluorophenyl)phosphine, dimethylphenylphosphine, methyldiphenylphosphine, are selected from the group consisting of phosphines, bis(tert-butyl)phenylphosphine, phosphites such as trimethylphosphite, triethylphosphite, arsines such as trifluoroarsine, trimethylarsine, tricyclohexylarsine, tri-tert-butylarsine, triphenylarsine, tris(pentafluorophenyl)arsine, stibines such as trifluorostibine, trimethylstibine, tricyclohexylstibine, tri-tert-butylstibine, triphenylstibine, tris(pentafluorophenyl)stibine, nitrogen-containing heterocycles such as pyridine, pyridazine, pyrazine, pyrimidine, triazine and carbenes, in particular Arduengo carbene.

[0048] Preferred monoanionic monodentate ligands L' are hydrides, deuterides, halides F - , Cl - , Br - and I - , alkyl acetylides, e.g. methyl-C≡C - , tert-Butyl-C≡C - , aryl acetylides, e.g. phenyl-C≡C -, cyanides, cyanates, isocyanates, thiocyanates, isothiocyanates, aliphatic or aromatic alkoxides such as methoxides, ethoxides, propoxides, isopropoxides, tert-butoxides, phenoxides, aromatic or aromatic thioalkoxides such as methanethiolates, ethanethiolates, propanethiolates, iso-propanethiolates, tert-thiobutoxides, thiophenoxides, amides such as dimethylamides, diethylamides, di-isopropylamides, morpholides, carboxylates such as acetates, trifluoroacetates, propionates, benzoic acid esters, aryl groups such as phenyl, naphthyl, and anionic nitrogen-containing heterocycles such as pyrrolides, imidazolides, pyrazolides. At the same time, the alkyl groups of these groups are preferably selected from C1-C 20 Alkyl groups, more preferably C1-C 10 Alkyl groups, most preferably C1-C4 alkyl groups. Aryl groups are understood to mean heteroaryl groups. These groups have the meanings given above.

[0049] Preferred di- or trianionic ligands are O 2- , S 2- , carbides leading to RC≡M type coordination, nitrenes leading to RN=M type coordination (where R is usually a substituent), or N 3- It is.

[0050] Preferred uncharged or mono- or dianionic, bidentate or more polydentate ligands L' are diamines, such as ethylenediamine, N,N,N',N'-tetramethylethylenediamine, propylenediamine, N,N,N',N'-tetramethylpropylenediamine, cis- or trans-diaminocyclohexane, cis- or trans-N,N,N',N'-tetramethyldiaminocyclohexane, imines, such as 2-[(1-(phenylimino)ethyl]pyridine, 2-[(1-(2-methylphenylimino)ethyl]pyridine, 2-[(1-(2,6-di-iso-propylphenylimino)ethyl]pyridine, 2-[(1-(methylimino)ethyl]pyridine, 2-[(1-(ethylimino)ethyl]pyridine, 2-[(1-(iso-propylimino)ethyl]pyridine, 2-[(1-(tert-butylimino)ethyl]pyridine, diimines, e.g. 1,2-bis(methylimino)ethane, 1,2-bis(ethylimino)ethane, 1,2-bis(iso-propylimino)ethane, 1,2-bis(tert-butylimino)ethane, 2,3-bis(methylimino)butane, 2,3-bis(ethylimino)butane, 2,3-bis(iso-propylimino)butane, 2,3-bis(tert-butylimino)butane, 1,2-bis(phenylimino)ethane, 1,2-bis(2-methylphenylimino)ethane 1,2-bis(2,6-diisopropylphenylimino)ethane, 1,2-bis(2,6-di-tert-butylphenylimino)ethane, 2,3-bis(phenylimino)butane, 2,3-bis(2-methylphenylimino)butane, 2,3-bis(2,6-diisopropylphenylimino)butane, 2,3-bis(2,6-di-tert-butylphenylimino)butane, heterocycles containing two nitrogen atoms, e.g. 2,2'-bipyridine, o-phenanthroline, diphosphines such as bis(diphenylphosphino)methane, bis(diphenylphosphino)ethane, bis(diphenylphosphino)propane, bis(diphenylphosphino)butane, bis(dimethylphosphino)methane, bis(dimethylphosphino)ethane, bis(dimethylphosphino)propane, bis(diethylphosphino)methane, bis(diethylphosphino)ethane, bis(diethylphosphino)propane, bis(di-tert-butylphosphino)methane, bis(di-tert-butylphosphino)ethane, bis(tert-butylphosphino)propane, 1,3-diketonates derived from 1,3-diketones such as acetylacetone, benzoylacetone, 1,5-diphenylacetylacetone, dibenzoylmethane, bis(1,1,1-trifluoroacetone), cetyl)methane, 3-ketonates derived from 3-ketoesters such as ethyl acetoacetate, carboxylates derived from aminocarboxylic acids such as pyridine-2-carboxylic acid, quinoline-2-carboxylic acid, glycine, N,N-dimethylglycine, alanine, N,N-dimethylaminoalanine, salicyliminates derived from salicylimines such as methyl salicylimine, ethyl salicylimine, phenyl salicylimine, dialkoxides derived from dialcohols such as ethylene glycol, 1,3-propylene glycol, and dithiolates derived from dithiols such as ethylene-1,2-dithiol, propylene-1,3-dithiol, bis(pyrazolyl borate), bis(imidazolyl) borate, 3-(2-pyridyl) diazole, or 3-(2-pyridyl) triazole.

[0051] Preferred tridentate ligands are the borates of nitrogen-containing heterocycles, such as tetrakis(1-imidazolyl)borate and tetrakis(1-pyrazolyl)borate.

[0052] More preferred are bidentate monoanionic, uncharged or dianionic ligands L', especially monoanionic ligands, which have a cyclometalated five- or six-membered ring, especially a cyclometalated five-membered ring, with at least one metal-carbon bond, together with the metal. These are in particular ligands commonly used in phosphorescent metal complexes of organic electroluminescent devices, namely ligands of the phenylpyridine, naphthylpyridine, phenylquinoline, phenylisoquinoline type, etc., each of which may be substituted by one or more radicals R. Many ligands of this type are known to those skilled in the art of phosphorescent electroluminescent devices, and further ligands of this type may be selected as ligand L' of compounds of formula (1) without the need to exercise inventive techniques. Particularly suitable combinations for this purpose are usually the two groups of formulae (40) to (88) below, where one group is preferably linked via an uncharged nitrogen atom or a carbene atom and the other group is preferably linked via a negatively charged carbon atom or a negatively charged nitrogen atom. Ligands L' can be formed from groups of formulae (40) to (88) on the basis that these groups are linked to each other at the positions indicated by #. The positions at which they are coordinated to the metal are indicated by *. These groups may be linked to ligand L via one or two bridging V units. [ka] [ka] [ka]

[0053] In these formulae, X and R have the meanings given above and W is NR, O or S. Preferably, in each group, not more than 3 groups X are N, more preferably, in each group, not more than 2 symbols X are N, even more preferably, in each group, not more than 2 symbols X are N. Especially preferably, all symbols X are CR.

[0054] At the same time, a fused heteroaryl group by ring formation from adjacent substituents can also be formed from two individual aryl or heteroaryl groups coordinated to M as a bidentate ligand L'.

[0055] Further suitable co-ligands L' which are not fully heteroaromatic but have keto groups in the ligand substructure are disclosed in WO2011 / 044988, WO2014 / 094962, WO2014 / 094961 and WO2014 / 094960.

[0056] Examples of suitable co-ligands L', in which the radicals of the respective coordinating groups form a ring system together, are shown in the table below, with the CAS numbers also given in each case. [ka] [ka]

[0057] When the ligand L' is composed of structures of formulae (40) to (88), the preferred radicals R in these structures are the same as those already given above for the radical R in formula (2) when X is CR.

[0058] The complexes of the present invention may be facial or pseudofacial, or they may be meridional or pseudomeridional.

[0059] The above mentioned preferred embodiments can be combined with one another if desired. In a particularly preferred embodiment of the invention, the above mentioned preferred embodiments apply simultaneously.

[0060] Examples of compounds of the present invention are those with the structures shown in the table below: [ka]

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[0061] The present invention further provides a method for preparing a metal complex compound of formula (1) by reaction of the corresponding free ligand L, and optionally L', with a metal alkoxide of formula (79), a metal ketoketonate of formula (80), a metal halide of formula (81), a dimeric metal complex of formula (82), or a metal complex of formula (83). [ka] wherein the symbols M, m, n and R have the meanings given above, Hal=F, Cl, Br or I, L″ is an alcohol (especially an alcohol having 1 to 4 carbon atoms), or a nitrile (especially acetonitrile or benzonitrile), and (Anion) is a non-coordinating anion, for example triflate.

[0062] This can be confirmed by the temperature regime of the reaction and, if necessary, the presence of blocking substituents to which ligand L is coordinated via two six-membered rings rather than one five-membered and one six-membered ring. More details on the reaction regime can be found in the Examples section.

[0063] Likewise, metal compounds, especially iridium compounds, can be used which have alkoxide and / or halide and / or hydroxy and ketoketonate radicals. These compounds may also be charged. Corresponding iridium compounds which are particularly suitable as reactants are disclosed in WO2004 / 085449. Particularly suitable is [IrCl2(acac)2] - , for example Na[IrCl2(acac)2], metal complexes with acetylacetonate derivatives as ligands, for example Ir(acac)3 or tris(2,2,6,6-tetramethylheptane-3,5-dionato)iridium, and IrCl3·xH2O, where x is typically a number between 2 and 4.

[0064] Suitable platinum reactants are, for example, PtCl2, K2[PtCl4], PtCl2(DMSO)2, Pt(Me)2(DMSO)2 or PtCl2(benzonitrile)2.

[0065] The synthesis of the complex is preferably carried out as disclosed in WO2002 / 060910, WO2004 / 085449 and WO2007 / 065523. Heteroleptic complexes can also be synthesized as disclosed, for example, in WO2005 / 042548. In this case, the synthesis is activated, for example, by thermal or photochemical methods and / or microwave radiation. For the activation of this reaction, it is also possible to further add a Lewis acid, for example, a silver salt or AlCl3.

[0066] The reaction can be carried out in the melt of the corresponding ligand to be ortho-metallated without the addition of solvents or melting aids. If necessary, solvents or melting aids can also be added. Suitable solvents are protic or aprotic solvents such as aliphatic and / or aromatic alcohols (methanol, ethanol, isopropanol, t-butanol, etc.), oligo- and polyalcohols (ethylene glycol, 1,2-propanediol or glycerol, etc.), alcohol ethers (e.g. ethoxyethanol, diethylene glycol, triethylene glycol, polyethylene glycol, etc.), ethers (di- 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, sulfolane, etc.). Suitable melting aids are compounds which are solid at room temperature but which melt when the reaction mixture is heated to dissolve the reactants to form a homogeneous melt. Particularly suitable are biphenyl, m-terphenyl, triphenylene, 1,2-, 1,3- or 1,4-bisphenoxybenzene, triphenylphosphine oxide, 18-crown-6, phenol, 1-naphthol, hydroquinone, and the like.

[0067] These processes, optionally followed by purification (e.g. recrystallization or sublimation), allow the compounds of formula (1) according to the invention to be obtained in a high purity, preferably greater than 99%, more preferably greater than 99.9% purity ( 1 1 H-NMR and / or HPLC), allowing for

[0068] The compounds of the invention may be solubilized by suitable substitution, for example with relatively long-chain alkyl groups (about 4 to 20 carbon atoms), especially branched alkyl groups, or optionally substituted aryl groups (e.g., xylyl, mesityl, or branched, terphenyl or quaterphenyl groups). Compounds of this type are soluble in standard organic solvents (e.g., toluene or xylene) at room temperature in sufficient concentrations to allow processing of the complex from solution. These soluble compounds are particularly well suited for processing from solution, for example by printing methods.

[0069] The formulation of the compounds according to the invention requires the preparation of the compounds according to the invention from liquid phase, for example by spin coating or printing.These formulations can be, for example, solutions, dispersions or emulsions.For this purpose, it may be preferable to use a mixture of two or more solvents. 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, α-terpineol, benzothiazole, butyl benzoate, cumene, cyclohexanol, cyclohexanone, cyclohexylbenzene, cyclohexylbenzene, decalin, dodecylbenzene, ethyl benzoate, indane, NMP, p-cymene, phenetol, 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, 2-methylbiphenyl, 3-methylbiphenyl, 1-methylnaphthalene, 1-ethylnaphthalene, ethyl octanoate, diethyl sebacate, octyl octanoate, heptylbenzene, menthyl isovalerate, cyclohexyl hexanoate or a mixture of these solvents.

[0070] Therefore, the present invention further relates to a formulation comprising the compound of the present invention and at least one further compound.The further compound is, for example, a solvent.The further compound can also be a further organic or inorganic compound, for example a matrix material, which is also used in electronic devices.

[0071] The compound of formula (1) and the preferred forms thereof can be used as an active ingredient in an electronic device. Therefore, the present invention further provides the use of a compound according to formula (1) or the preferred forms thereof in an electronic device.

[0072] An electronic device is understood to mean any device comprising an anode, a cathode and at least one layer, which layer comprises at least one organic or organometallic compound. Thus, an electronic device according to the invention comprises an anode, a cathode and at least one layer comprising at least one compound of formula (1) as described above. Preferred electronic devices are selected from the group consisting of 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), organic optical detectors, organic photoreceptors, organic field quenching devices (O-FQD), light emitting electrochemical cells (LEC) and organic laser diodes (O-laser), which comprise at least one compound of formula (1) as described above in at least one layer. Particularly preferred are organic electroluminescent devices. The active component is usually an organic or inorganic material introduced between the anode and the cathode, such as a charge injection, charge transport or charge blocking material, in particular a light-emitting material and a matrix material. The compounds of the present invention show particularly good properties as light-emitting materials in organic electroluminescent devices. The preferred embodiment of the present invention is therefore an organic electroluminescent device. Furthermore, the compounds of the present invention may be used for the generation of singlet oxygen, for photocatalysis or for photoconversion (e.g. pixel color converter (PCC)).

[0073] An organic electroluminescent device comprises a cathode, an anode and at least one light-emitting layer. Apart from these layers, it may 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 generating layers and / or organic or inorganic p / n bonds. Here, one or more hole transport layers can also be p-doped, for example by metal oxides such as MoO3 or WO3 or (per)fluorinated electron-deficient aromatic systems, and / or one or more electron transport layers can be n-doped. It is also possible for intermediate layers to be introduced between two light-emitting layers, for example having exciton-blocking function and / or controlling the charge balance in the electroluminescent device. However, it should be noted that not all of these layers necessarily need to be present.

[0074] In this case, the organic electroluminescent element may include an emitting layer or may include multiple emitting layers. If multiple emitting layers are present, they preferably have multiple maximum emission wavelengths between 380 nm and 750 nm in total, resulting in an overall white emission, in other words, various emitting compounds, which may be fluorescent or phosphorescent, are used in the emitting layers. Particularly preferred are three-layer structures with blue, green and orange or red emission (basic structures see, for example, WO2005 / 011013) or systems with more than three emitting layers. The system may be a hybrid system in which one or more layers are fluorescent and one or more layers are phosphorescent.

[0075] In a preferred embodiment of the invention, the organic electroluminescent device comprises, in one or more light-emitting layers, as light-emitting compound, a compound of formula (1) or the preferred forms described above.

[0076] When the compound of formula (1) is used as a light-emitting compound in the light-emitting layer, it is preferably used in combination with one or more matrix materials. The mixture comprising the compound of formula (1) and the matrix material comprises 0.1 to 99% by volume, preferably 1 to 90% by volume, more preferably 3 to 40% by volume, and in particular 5 to 15% by volume of the compound of formula (1), based on the total mixture comprising the light-emitting body and the matrix material. Correspondingly, the mixture comprises 99.9 to 1% by volume, preferably 99 to 10% by volume, more preferably 97 to 60% by volume, and in particular 95 to 85% by volume of the matrix material, based on the total mixture comprising the light-emitting body and the matrix material.

[0077] The matrix material used may generally be any material known for the purpose in accordance with the prior art. It is preferred that the triplet level of the matrix material is higher than the triplet level of the emitter.

[0078] Suitable matrix materials for the compounds of the invention are ketones, phosphine oxides, sulfoxides and sulfones (for example according to WO2004 / 013080, WO2004 / 093207, WO2006 / 005627 or WO2010 / 006680), triarylamines, carbazole derivatives (for example CBP (N,N-biscarbazolylbiphenyl), m-CBP, or derivatives according to WO2005 / 039246, US2005 / 0069729, JP ... 004 / 288381, EP 1205527, WO 2008 / 086851 or US 2009 / 0134784), indolocarbazole derivatives (for example according to WO 2007 / 063754 or WO 2008 / 056746), indenocarbazole derivatives (for example according to WO 2010 / 136109 or WO 2011 / 000455), azacarbazole derivatives (for example according to EP 1617710, EP 16177 11, EP1731584, JP2005 / 347160), bipolar matrix materials (for example, according to WO2007 / 137725), silanes (for example, according to WO2005 / 111172), azacarbazoles or boronic acid esters (for example, according to WO2006 / 117052), diazasilole derivatives (for example, according to WO2010 / 054729), diazaphosphole derivatives (for example, according to WO2010 / 054730), triazine derivatives (e.g. according to WO2010 / 015306, WO2007 / 063754 or WO2008 / 056746), zinc complexes (e.g. according to EP652273 or WO2009 / 062578), dibenzofuran derivatives (e.g. according to WO2009 / 148015), bridged carbazole derivatives (e.g. according to US2009 / 0136779, WO2010 / 050778, WO2011 / 042107 or WO2011 / 088877).

[0079] 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. A preferred combination is, for example, the use of aromatic ketones, triazine derivatives or phosphine oxide derivatives together with triarylamine derivatives or carbazole derivatives as a mixed matrix of the metal complex according to the invention. Likewise, it is also preferred to use a mixture of charge-transporting matrix materials and electrically inactive matrix materials (for example, as disclosed in WO2010 / 108579) that do not take any obvious part, if any, in charge transport.

[0080] Preferred biscarbazoles that can be used as matrix materials for the compounds of the present invention have the structures of formulas (84) and (85) below. [ka] Here, Ar 1 are identical or different, aromatic or heteroaromatic ring systems having 5 to 40 aromatic ring atoms, preferably 6 to 30 aromatic ring atoms, in each case optionally substituted by one or more R radicals, A 1 is NR, CR2, O or S, and R has the meaning given above. In a preferred embodiment of the invention, A 1 is CR2.

[0081] Preferred forms of the compounds of formulae (84) and (85) are the compounds of formulae (84a) and (85a) below. [ka] Here, the symbols used have the meanings given above.

[0082] Examples of suitable compounds of formula (84) and (85) are those depicted below. [ka] [ka]

[0083] A preferred dibenzofuran derivative is the compound of the following formula (86): [ka] where oxygen may be replaced by sulfur to form dibenzothiophene, L is a single bond or an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, optionally substituted by one or more R radicals, and R and Ar 1 has the meaning described above, where two Ar 1 group, or one Ar bonded to the same nitrogen atom 1 It is also possible for a group and one of the L groups to be linked together to form, for example, a carbazole.

[0084] Preferred carbazole amines are of the structures of formulas (87), (88) and (89) below. [ka] where L is an aromatic or heteroaromatic ring system having 5 to 30 aromatic ring atoms, optionally substituted by one or more R radicals, and R and Ar 1 has the meaning given above.

[0085] Preferred triazine, quinazoline or pyrimidine derivatives which can be used in mixtures with the compounds of the present invention are compounds of formulae (90), (91) and (92) below. [ka] Here, Ar 1 and R has the meaning given above.

[0086] Particularly preferred are the triazine derivatives of the formula (90) and the quinazoline derivatives of the formula (92), in particular the triazine derivatives of the formula (90).

[0087] In a preferred embodiment of the present invention, Ar in formulae (90), (91) and (92) 1 is identical or different at each occurrence and is an aromatic or heteroaromatic ring system having 6 to 30 aromatic ring atoms, in particular 6 to 24 aromatic ring atoms, optionally substituted by one or more R radicals. 1 Ar 1 , Ar 2 and Ar 3 The forms of these, particularly the structures of Ar-1 to Ar-76, are the same as those defined above.

[0088] Examples of suitable triazine compounds which may be used as matrix materials together with the compounds of the present invention are those listed in the table below. [ka] [ka] [ka]

[0089] More preferably, the mixture of two or more triplet emitters and matrix is ​​used.In this case, the triplet emitter with short wavelength emission spectrum functions as a co-matrix of the triplet emitter with long wavelength emission spectrum.For example, the complex of formula (1) of the present invention can also be used as a co-matrix of the triplet emitter with long wavelength emission (e.g., the triplet emitter that emits green or red).

[0090] The compounds according to the invention can be used in other functions in electronic devices, such as hole transport materials in hole injection or transport layers, charge generation materials, or electron blocking materials.Similarly, the complexes according to the invention can be used as matrix materials for other phosphorescent metal complexes in light-emitting layers.

[0091] A preferred cathode is a metal, metal alloy or multilayer structure of various metals with a low work function, such as alkaline earth metals, alkali metals, metals of the main group or lanthanides (e.g. Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.). Also suitable are alloys containing alkali metals or alkaline earth metals and silver (e.g. alloys containing magnesium and silver). In the case of multilayer structures, further metals with a relatively high work function (e.g. Ag) may also be used in addition to the metals, in which case combinations of metals such as Mg / Ag, Ca / Ag or Ba / Ag are commonly used. It may also be preferable to introduce a thin intermediate layer of a material with a high dielectric constant between the metal cathode and the organic semiconductor. Examples of materials useful for this purpose are fluorides of alkali metals or alkaline earth metals, but also the corresponding oxides or carbonates (e.g. LiF, Li2O, BaF2, MgO, NaF, CsF, Cs2CO3, etc.). The thickness of this layer is preferably 0.5 to 5 nm.

[0092] A preferred anode is a material with a high work function. Preferably, the anode has a work function greater than 4.5 eV against vacuum. Firstly, metals with high redox potentials are suitable for this purpose. For example, Ag, Pt or Au. Secondly, metal / metal oxide electrodes (for example, Al / Ni / NiOx, Al / PtOx) are also preferred. In some applications, at least one electrode should be transparent or partially transparent. This is to allow the emission or light emission (OLED / PLED, O-laser) of the organic material (O-SC). Here, preferred anode materials are highly conductive mixed metal oxides. Particularly preferred are iridium tin oxide (ITO) or indium tin oxide (IZO). Furthermore, preferred are conductive doped organic materials, in particular conductive doped polymers, such as PEDOT, PANI or derivatives of these polymers. More preferably, when p-doped hole transport material is applied to the anode as hole injection layer, suitable p-dopants are metal oxides such as MoO3 or WO3 or (per)fluorinated electron-deficient aromatic systems.More suitable p-dopants are HAT-CN (hexacyanohexaazatriphenylene) or compound NPD9 from Novaled.Such layers facilitate hole injection in materials with low HOMO, i.e. large HOMO value.

[0093] Any material used for a layer in the prior art can generally be used for the further layers. A person skilled in the art will be able to combine the respective material with the material according to the invention in an electronic device without inventive effort.

[0094] The components are correspondingly structured (depending on the application), connected and finally sealed, since the lifetime of such components is dramatically shortened in the presence of water and / or air.

[0095] More preferably, one or more layers are applied by sublimation, the material typically being -5 Less than mbar, preferably less than 10 -6An organic electroluminescent device characterized in that it is applied by vapor deposition in a vacuum sublimation unit at an initial pressure of less than 10 mbar. The initial pressure can be lower or even higher, for example 10 -7 It may be less than mbar.

[0096] Likewise preferred is an organic electroluminescent device, characterized in that one or more layers are applied by using the OVPD (organic vapor phase deposition) method or by means of carrier gas sublimation. In this case, the material is preferably 10 -5 It is applied at pressures between mbar and 1 bar. A special version of this method is the OVJP (Organic Vapor Jet Printing) method, in which the material is applied and structured directly through a nozzle (e.g. M.S. Arnold et al., Appl. Phys. Lett. 2008, 92, 053301).

[0097] Further preferred is an organic electroluminescent device, characterized in that one or more layers are produced from solution, for example by spin-coating or by any printing method, such as screen printing, flexographic printing, offset printing or nozzle printing, particularly preferably by LITI (Light Induced Thermal Imaging, Thermal Transfer Printing) or inkjet printing. For this purpose, soluble compounds are required, which can be obtained, for example, via suitable substitution.

[0098] Organic electroluminescent devices may also be prepared as hybrid systems by applying one or more layers from solution and one or more other layers by vapor deposition. For example, an emissive layer comprising a compound of formula (1) and a matrix material may be applied from solution, plus a hole blocking layer and / or an electron transport layer may be applied by vapor deposition under reduced pressure.

[0099] These methods are generally known to those skilled in the art and can be applied without difficulty to organic electroluminescent devices comprising the compounds of formula (1) or the preferred forms described above.

[0100] The electronic device, particularly the organic electroluminescent device, according to the present invention is distinguished by good color coordination, good efficiency and good life span. The present invention will be described in detail by the following examples, but is not intended to be limited thereto. Based on the description, a person skilled in the art will be able to manufacture further electronic devices without inventive ingenuity, and will be able to implement the present invention throughout the scope of the claims. EXAMPLES

[0101] Working Example: The following syntheses are carried out in dry solvents under a protective gas atmosphere unless otherwise stated. Metal complexes are furthermore handled with the exclusion of light or under yellow light. Solvents and reagents can be purchased, for example, from sigma-ALDRICH or ABCR. The numbers in brackets or the numbers given for the individual compounds refer to the CAS numbers of the compounds known from the literature. In the case of compounds which may have multiple enantiomeric, diastereomeric or tautomeric forms, one form is shown as representative.

[0102] A: Synthesis of synthon S Example S1: [ka] To a mixture of 29.8 g (100 mmol) of 11-bromobenz[c]imidazo[1,2-a][1,5]naphthyridine [2253277-62-9], 26.7 g (105 mmol) of bis(pinacolato)diborane, 29.4 g (300 mmol) of potassium acetate (anhydrous), 50 g of glass beads (diameter 3 mm) and 500 ml of THF, 821 mg (2 mmol) of SPhos and 225 mg (1 mmol) of palladium(II) acetate are added with good stirring and the mixture is heated under reflux for 16 hours. While the mixture is further warmed, the salts and glass beads are suction filtered through a bed of Celite in the form of a THF slurry, which is washed with THF, and the filtrate is concentrated to dryness. The residue is taken up in 100 ml of MeOH, stirred in warm solvent, the crystallized product is filtered off with suction, washed once with 30 ml each of methanol and dried under reduced pressure. Yield: 30.0 g (81 mmol), 81%; Purity: about 95% 1 Measured by H-NMR.

[0103] The following compounds may be prepared similarly: [ka]

[0104] Example S50: [ka] To a mixture of 34.5 g (100 mmol) of S1, 28.3 g (100 mmol) of 1-bromo-2-iodobenzene [583-55-1], 31.8 g (300 mmol) of sodium carbonate, 300 ml of toluene, 100 ml of ethanol and 300 ml of water, 788 mg (3 mmol) of triphenylphosphine and 225 mg (1 mmol) of palladium(II) acetate are added with good stirring and the mixture is heated under reflux for 48 h. After cooling, the organic phase is removed, washed once with 300 ml of water and once with 300 ml of saturated sodium chloride solution and dried over magnesium sulfate. The drying agent is filtered and the filtrate is thoroughly concentrated under reduced pressure. The residue is subjected to flash chromatography (Trent automatic column system by A. Semrau) or recrystallized from acetonitrile / ethyl acetate. Yield: 31.8g (85mmol), 85%; Purity: approx. 95% 1 Measured by H-NMR.

[0105] The following compounds may be prepared similarly: [ka]

[0106] Synthesis of ligand L: 1) Synthesis of tetradentate TL ligand: Example TL1: [ka]

[0107] A) [ka] To a suspension of 15.2 g (50 mmol) of 6-chlorobenzimidazo[2,1-f]benzo[h][1,6]naphthyridine [1228276-32-0] in 200 ml of THF cooled to -78°C, 59.0 ml (100 mmol) of tert-butyllithium (1.7 M in n-pentane) is added dropwise, and the mixture is stirred for another 2 h. Then, a solution of 10.8 g (60 mmol) of 3-(2-pyridyl)benzonitrile [4350-51-0] previously cooled to -78°C is added dropwise, the mixture is stirred for another 1 h at -78°C, and then gradually allowed to warm to room temperature. The reaction mixture is quenched by adding 20 ml of methanol, then 100 ml of 5N hydrochloric acid is added, and the mixture is heated under reflux for 2 h. The mixture is adjusted to pH ~9 by adding 5N aqueous NaOH and extracted three times with 200 ml each of dichloromethane. The combined organic phases are washed three times with 300 ml each of water and once with 300 ml of saturated sodium chloride and dried over magnesium sulfate. The desiccant is suction filtered, washed thoroughly with dichloromethane and the filtrate is concentrated to dryness. The crude product is chromatographed on silica gel with dichloromethane / ethyl acetate (8:2 vv). Yield: 7.7 g (17 mmol) 34%; purity: about 95% 1 Measured by H-NMR.

[0108] B) To a solution of 7.0 g (30 mmol) of 2-bromobiphenyl [2052-07-5] in 100 ml of THF cooled to -78 °C, 12.0 ml (30 mmol) of n-butyllithium (2.5 N in hexane) is added dropwise, and the mixture is stirred for another 30 min. Then, a solution of 13.5 g (30 mmol) of TL1 stage A) in 200 ml of THF is added dropwise, the mixture is slowly brought to room temperature and stirred for another 6 h. The reaction mixture is quenched by adding 10 ml of ethanol, the solvent is completely distilled off under reduced pressure, the residue is taken up in 200 ml of glacial acetic acid, 1 ml of concentrated sulfuric acid is added with stirring, and the mixture is stirred for another 3 h at 60 °C. Then, the glacial acetic acid is largely removed under reduced pressure, the residue is taken up in 300 ml of dichloromethane, and the mixture is alkalized by adding 5 wt % aqueous NaOH solution while cooling with ice. The organic phase is separated, washed three times with 200 ml of water each time, dried over magnesium sulfate, the organic phase is completely concentrated, the residue is taken up in 300 ml of methanol, homogenized under heating and stirred for another 12 hours during which the product crystallizes. The crude product is suction filtered, washed once with 30 ml of methanol each time, dried under reduced pressure and recrystallized twice from toluene:isopropanol (5:1). Yield: 6.5 g (11 mmol) 37%; purity: about 95% 1 Measured by H-NMR. [ka] [ka]

[0109] 2) Synthesis of hexadentate ligand HL: Example HL1: [ka] To a mixture of 66.3 g (100 mmol) of 2,2'-[5''-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)[1,1':2',1'':3'',1''':2''',1''''-quinquephenyl]-4,4''''-diyl]bispyridine [1989597-72-9], 37.4 g (100 mmol) of S50, 63.7 g (300 mmol) of potassium triphosphate, 300 ml of toluene, 150 ml of dioxane and 300 ml of ethanol, 1.64 g (4 mmol) of SPhos and 449 mg (2 mmol) of palladium(II) acetate are added with good stirring, and the mixture is heated under reflux for 24 hours. After cooling, the organic phase is removed, washed twice with 300 ml each of water and once with 300 ml of saturated sodium chloride solution, and dried over magnesium sulfate. The drying agent is filtered off, the filtrate is concentrated to dryness under reduced pressure, and the glassy crude product is recrystallized once from acetonitrile (~150 ml) and once by boiling from acetonitrile / ethyl acetate. Yield: 58.1 g (70 mmol), 70%; purity: about 95% 1 Measured by H-NMR. [ka] [ka] [ka]

[0110] Synthesis of C metal complexes: 1) Synthesis of homoleptic iridium complexes of the IrL3 type: Homoleptic tris-facial iridium complexes: Variant A: Tris(acetylacetonato)iridium(III) as an iridium reactant A mixture of 10 mmol of tris(2,2,6,6-tetramethyl-3,5-heptanedionato)iridium(III) [99581-86-9] and 60 mmol of ligand L was placed in a 50 mL glass ampoule under reduced pressure (10 -5The ampoule is sealed by dissolving at 1000 psi (0.25 mbar). The ampoule is heated at a specific temperature for a specific time, during which the dissolved mixture is stirred using a magnetic stirrer. If appropriate, a high-boiling alkane (e.g. octadecane) is added. After cooling (note: the ampoule is usually under reduced pressure!), the ampoule is opened and the sinter cake is stirred and mechanically disintegrated in 100 ml of a specified suspension medium with 100 g of glass beads (diameter 3 mm). The fine suspension is decanted, the glass beads are removed, the solid is suction filtered and dried under reduced pressure. The solid is dissolved in dichloromethane, adsorbed on Isolute SI (Biotage) and subjected to column chromatography on silica gel with dichloromethane. Further purification is performed by successive hot extractions. The solid is placed on a 5 cm alumina bed (alumina, base activity 1) and extracted with a specified extractant (initial charge approx. 500 ml). The solid from the suspension thus obtained is filtered off with suction, washed with about 50 ml of methanol and dried. After drying, the purity of the metal complex is determined by NMR and / or HPLC. If the purity is less than 99.5%, the hot extraction step is repeated. Once a purity of 99.5%-99.9% is achieved, the metal complex is heat treated or sublimed. The heat treatment is carried out in a temperature range of 200-350 °C under high vacuum (p about 10 -6 The sublimation is carried out at a temperature range of about 320 to about 450 °C and in a high vacuum (p about 10 -6 The process is carried out at low pressures (mbar) and preferably in the form of fractional sublimation. [ka]

[0111] 2) Synthesis of L'2IrL type heteroleptic iridium complexes: To a well-stirred suspension of 5 mmol of a specific iridium reactant of the [L2IrCl]2 type, 10 mmol of the ligand L and 50 g of glass beads (diameter 3 mm) in 200 ml of 1,2-dichloromethane, 60 mmol of triethylamine and 10 mmol of silver trifluoromethanesulfonate are added and the mixture is stirred at 90 ° C for 24 hours. While the mixture is still warm, the precipitated silver chloride is filtered using a bed of silica gel in the form of a slurry, which is washed with a little 1,2-dichloroethane, and the filtrate is concentrated to dryness. The crude product is then chromatographed on silica gel (eluents: dichloromethane, toluene, ethyl acetate, acetone, THF, cyclohexane, n-heptane, etc.; and / or mixtures thereof). Further purification is carried out as described in 1) by successive hot extractions and thermal treatment under high vacuum or fractional sublimation. [ka] [ka] [ka]

[0112] 3) Synthesis of Pt complexes with tetradentate ligands of the Pt(TL) type: A mixture of 10 mmol of ligand L, 10 mmol of K2PtCl4, 400 mmol of lithium acetate (anhydrous) and 200 ml of glacial acetic acid is heated to 150 °C for 60 h in a stirred autoclave. After cooling and addition of 200 ml of water, the precipitated solids are filtered, which are extracted twice in hot ethanol / water (1:1 vv) by stirring, suction filtered and washed three times with 50 ml of ethanol each. The crude product is subsequently chromatographed on silica gel (eluents: dichloromethane, toluene, ethyl acetate, acetone, THF, cyclohexane, n-heptane, etc.; and / or mixtures thereof). Further purification is carried out as described in 1) by successive hot extractions and thermal treatment under high vacuum or fractional sublimation. [ka]

[0113] 4) Synthesis of Iridium Complexes with Ir(HL)-type Hexadentate Ligands: A mixture of 10 mmol of the ligand HL, 4.90 g (10 mmol) of trisacetylacetonatoiridium(III) [15635-87-7] and 120 g of hydroquinone [123-31-9] is initially introduced into a 1000 ml two-neck round-bottom flask equipped with a glass-coated magnetic bar. The flask is equipped with a water separator (for media less dense than water) and an argon-blanketed air cooler. The flask is placed on a metal heat bath. The apparatus is purged with argon for 15 minutes from above with an argon blanket system, allowing argon to flow through the side of the two-neck flask. Through the side of the two-neck flask, a glass-coated Pt-100 thermocouple is introduced into the flask, with its end positioned just above the magnetic stir bar. The apparatus is then insulated by several loose rolls of household aluminum foil, the insulation reaching the center of the riser tube of the water separator. The apparatus is then rapidly heated to 250-255 °C (measured by a Pt-100 temperature sensor attached to the molten stirred reaction mixture) by the laboratory's stirring heating system. For another 2 hours, the reaction mixture is kept at 250-255 °C, during which a small amount of condensate is distilled off and collected in a water separator. After 2 hours, the mixture is cooled to 190 °C, the heating bath is removed, and 100 ml of ethylene glycol is added dropwise. After cooling to 100 °C, 400 ml of methanol is slowly added dropwise. The yellow suspension thus obtained is filtered through a double-headed frit, the yellow solid is washed three times with 50 ml of methanol and dried under reduced pressure. Crude yield: quantitative. The solid thus obtained is dissolved in 200-500 ml of dichloromethane and filtered through about 1 kg of dichloromethane-preslurried silica gel (column diameter about 18 cm) in the dark, excluding air, leaving the original dark components. The core fraction is removed and concentrated on a rotary evaporator with simultaneous continuous dropwise addition of MeOH until crystallization.After being removed by suction, washed with a little MeOH and dried under reduced pressure, the orange product is further purified by successively hot-extracting 4 times with dichloromethane / isopropanol 1:1 (vv) and 4 times with dichloromethane / acetonitrile, with careful exclusion of air and light (initial input volume in each case about 200 ml, extraction thimble: standard Soxhlet thimble made of cellulose by Whatman). Losses to the mother liquor can be adjusted by the ratio of dichloromethane (low boiling point and good solubility): isopropanol or acetonitrile (high boiling point and poor solubility). Typically 3-6 wt% of the amount used. Hot extraction can also be performed with other solvents such as toluene, xylene, ethyl acetate, butyl acetate, etc. Finally, the product is p~10. -6 Fractionally sublimed or heat treated at high vacuum of 1000 mbar and T~350~430°C. Typical purity >99.7%. [ka] [ka] [ka]

[0114] Example: OLED manufacturing 1) Vacuum processed elements: OLEDs according to the invention and OLEDs according to the prior art are produced by the general method described in WO2004 / 058911, adapted to the circumstances described here (layer thickness range, materials used). The following examples show the results for different OLEDs. Cleaned glass plates (cleaned in a Miele laboratory glass washer, Extran detergent from Merck) coated with 50 nm thick structured ITO (indium tin oxide) are pretreated with UV ozone for 25 minutes (PR-100 UV ozone generator from UVP) and within 30 minutes are coated with 20 nm of PEDOT:PSS (poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate), purchased as CLEVIOS® P VP AI 4083 from Heraeus Precious Metals GmbH, Germany, spin-coated from an aqueous solution) for process improvement and baked at 180° C. for 10 minutes. These coated glass plates form the substrates on which the OLEDs are applied.

[0115] The OLED basically has the following layer structure: substrate / Hole Injection Layer 1 (HIL1) made of HTM1 doped with 5% NDP-9 (commercially available from Novaled), 20 nm / Hole Transport Layer 1 (HTL1) made of HTM1, 220 nm for green / yellow devices and 110 nm for red devices / Hole Transport Layer 2 (HTL2) / Emitting Layer (EML) / Hole Blocking Layer (HBL) / Electron Transport Layer (ETL) / Optional Electron Injection Layer (EIL) / and finally the cathode. The cathode is formed by a 100 nm thick layer of aluminum.

[0116] First, vacuum processed OLEDs are described. For this purpose, all materials are applied by thermal evaporation in a vacuum chamber. Here, the emitting layer always consists of at least one matrix material (host material) and a light-emitting dopant (emitter) mixed in a certain volume ratio into the matrix material by co-evaporation. Here, a specification given in the form M1:M2:Ir(L1) (55%:35%:10%) means that the material M3 is present in the layer in a volume ratio of 55%, M2 in the layer in a volume ratio of 35% and Ir(L1)3 in the layer in a proportion of 10%. Similarly, the electron transport layer may also consist of a mixture of two materials. The exact structure of the OLED is given in Table 2. The materials used in the manufacture of the OLED are given in Table 4.

[0117] OLEDs are characterized by standard methods. For this purpose, the electroluminescence spectrum, the current efficiency (measured in cd / A), the current efficiency (measured in lm / W) and the external quantum efficiency (EQE, measured in percent) as a function of luminous density are calculated from the current / voltage / current density characteristic line (IUL characteristic line), assuming a Lambertian emission characteristic, and the lifetime is determined. The electroluminescence spectrum is measured at a luminous density of 1000 cd / m 2 The CIE 1931 x and y color coordinates are calculated from this. The lifetime LT50 is determined when the luminous flux density is an initial luminous density of 1000 cd / m 2 It is defined as the time it takes for the luminous flux density to drop to 50% of the initial value.

[0118] The OLED may also be initially operated at different initial luminances, and the lifetime values ​​may be converted to other initial luminance values ​​using conversion formulas known to those skilled in the art.

[0119] Use of the compounds of the present invention as emissive materials in phosphorescent OLEDs One use of the compounds of the present invention is as a phosphorescent light-emitting material in the emissive layer in an OLED. OLED results are summarized in Table 2. [Table 1-1] [Table 1-2] [Table 2]

[0120] Solution-processed devices: A: Low molecular weight soluble functional materials The iridium complexes of the invention can also be processed from solution, resulting in OLEDs that, while having good properties, are very simple in terms of processing technology compared to vacuum-processed OLEDs. The production of such components is based on the production of polymer light-emitting diodes (PLEDs), which have already been described many times in the literature (e.g. WO 2004 / 037887). The structure consists of: substrate / ITO / hole injection layer (60 nm) / interlayer (20 nm) / emissive layer (60 nm) / hole blocking layer (10 nm) / electron transport layer (40 nm) / cathode. For this purpose, a substrate (soda-lime glass) from Technoprint is used, to which an ITO structure (indium tin oxide, transparent conductive anode) is applied. The substrate is cleaned in a clean room with DI water and detergent (Deconex 15PF) and then activated by UV / ozone plasma treatment. Afterwards, also in the clean room, a 20 nm hole injection layer is applied by spin coating. The required spin speed depends on the degree of dilution and the geometry of the particular spin coater. To remove residual water from the layers, the substrate is baked on a hotplate at 200 ° C for 30 min. The intermediate layer used serves for hole transport. In this case, HL-X from Merck is used. The intermediate layer can be replaced by one or more layers, which only have to fulfill the condition that they are not desorbed again by the subsequent processing step of EML deposition from solution. For the production of the emissive layer, the triplet emitter of the invention is dissolved in toluene or chlorobenzene together with a matrix material. Here, the typical solid content of the solution is 16-25 g / l, if a typical layer thickness for the device of 60 nm is achieved by spin coating. The solution-processed type 1 devices contain an emissive layer composed of M4:M5:IrL (40%:58%:22%) and type 2 a emissive layer composed of M4:M5:IrLa:IrLb (30%:34%:29%:7%). That is, they contain two different Ir complexes. The percentage figures in the case of materials processed from solution mean weight %. The light-emitting layer is applied by spin-coating in an inert gas atmosphere, in the present case argon, and heated at 160° C. for 10 minutes.On top of the latter, a hole blocking layer (10 nm ETM1) and an electron transport layer (40 nm ETM1(50%) / ETM2(50%)) are evaporated (e.g., in a Lesker evaporation system, typical evaporation pressure is 5×10). -6 mbar). Finally, a cathode of aluminium (100 nm) is applied by evaporation (high purity metal from Aldrich). To protect the device from air and atmospheric moisture, it is finally encapsulated and then characterized. The OLED example is not yet optimised. Table 3 summarises the results obtained. The lifetime LT50 is determined for a luminous density of 1000 cd / m2 at an initial luminous density of 1000 cd / m2. 2 It is defined as the time it takes for the luminous flux density to drop to 50% of the initial value. [Table 3] [Table 4-1] [Table 4-2]

[0121] Comparison with prior art The complexes shown below with similar ligands to those of the present invention (where the ligands are coordinated via a five-membered and a six-membered ring rather than via two six-membered rings according to the present invention) are disclosed in US2012 / 0153816. [ka]

[0122] For the two complexes, CIE color coordinates of CIEx / y 0.19 / 0.28 are reported. The complexes coordinated to iridium via one five-membered ring and one six-membered ring exhibit blue emission, whereas the complexes of the present invention exhibit green, yellow, or red emission.

Claims

1. Partial structure M(L) of formula (2) ｎ A compound of formula (1) comprising: M (L) ｎ (L') ｍ Formula (1) 【Chemistry 1】 (where the symbols and subscripts used are as follows: M is iridium or platinum; D is C or N, where one D is C and the other D is N; X is the same or different at each occurrence and is CR or N; R is the same or different at each occurrence and is H, D, F, Cl, Br, I, N (R １ ) ２ , C.N., N.O. ２ , OR １ , S.R. １ , COOR １ , C(=O)N(R １ ) ２ , Si(R １ ) ３ , B(OR １ ) ２ , C(=O)R １ , P(=O)(R １ ) ２ , S(=O)R １ , S(=O) ２ R １ , OSO ２ R １ , a linear alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group is in each case one or more R １ radical, wherein one or more non-adjacent CH ２ The group is Si(R １ ) ２ , C=O, NR １ , O, S or CONR １ or having 5 to 60 aromatic ring atoms, preferably 5 to 40 aromatic ring atoms, in each case one or more R １ an aromatic or heteroaromatic ring system, optionally substituted by a radical; at the same time, two R radicals together may form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system; R １ are the same or different for each occurrence, H, D, F, Cl, Br, I, N (R ２ ) ２ , C.N., N.O. ２ , OR ２ , S.R. ２ , Si(R ２ ) ３ , B(OR ２ ) ２ , C(=O)R ２ , P(=O)(R ２ ) ２ , S(=O)R ２ , S(=O) ２ R ２ , OSO ２ R ２ , a linear alkyl group having 1 to 20 carbon atoms, or an alkenyl or alkynyl group having 2 to 20 carbon atoms, or a branched or cyclic alkyl group having 3 to 20 carbon atoms, wherein the alkyl, alkenyl or alkynyl group is each one of one or more R ２ radical, wherein one or more non-adjacent CH ２ The group is Si(R ２ ) ２ , C=O, NR ２ , O, S or CONR ２ and in which one or more hydrogen atoms in the alkyl, alkenyl or alkynyl group may be replaced by D, F, Cl, Br, I or CN), or having 5 to 40 aromatic ring atoms, in each case one or more R ２ an aromatic or heteroaromatic ring system, optionally substituted by a radical; １ the radicals together may form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system; R ２ is the same or different at each occurrence and is H, D, F, CN or an aliphatic, aromatic or heteroaromatic organic radical having 1 to 20 carbon atoms, in particular a hydrocarbyl radical, in which one or more hydrogen atoms may be replaced by F; L' is the same or different at each occurrence and is a ligand; n is 1, 2 or 3; m is 0, 1, 2, 3 or 4; At the same time, it is also possible for two or more ligands L to be linked together or for L to be linked to L' by a single bond or a divalent or trivalent bridge to form a tridentate, tetradentate, pentadentate or hexadentate ligand system.

2. 2. The compound according to claim 1, characterized in that the unit of formula (2) is selected from the structure of formula (3). 【Chemistry 2】 (wherein the symbols and subscripts used have the same meaning as in claim 1)

3. 3. The compound according to claim 1 or 2, characterized in that the unit of formula (2) is selected from the structures of formulae (3a) to (3f) and (4a) to (4f) 【Chemistry 3】 (wherein the symbols and subscripts used have the meanings set out in claim 1)

4. The compound according to any one of claims 1 to 3, characterized in that the unit of formula (2) is selected from the structures of formulae (3a-1) to (4f-1). 【Chemistry 4】 wherein the symbols and subscripts used have the meanings given in claim 1 and R' has the same meaning as R, where at least one substituent R' is not H or D.

5. The compound according to any one of claims 1 to 4, wherein the unit of formula (2) is selected from the structures of formulae (3a-2) to (4a-6). 【Chemistry 5-1】 【Chemistry 5-2】 (wherein the symbols and subscripts used have the meanings set out in claim 1)

6. R is the same or different at each occurrence and is H, D, F, Br, I, N (R １ ) ２ , CN, Si(R １ ) ３ , B(OR １ ) ２ , a linear alkyl group having 1 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms, or a branched or cyclic alkyl group having 3 to 10 carbon atoms (each of which may be one or more R １ radicals, in which one or more hydrogen atoms may be replaced by D or F), or having 5 to 24 aromatic ring atoms, in each case one or more R １ Compounds according to any one of claims 1 to 5, characterized in that they are selected from the group consisting of aromatic or heteroaromatic ring systems, optionally substituted by R radicals; and at the same time, two, preferably adjacent, R radicals may together form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system.

7. The compound according to any one of claims 1 to 6, which is selected from the structures of formulas (12) to (15). 【Chemistry 6】 (wherein the symbols and subscripts used have the meanings set out in claim 1)

8. 8. A compound according to claim 7, characterized in that V in the compounds of formula (12) and (13) is a group of formula (26) in which the dotted bond indicates the point of attachment of the ancillary ligands L and L'. 【Chemistry 7】 (where: X １ is the same or different at each occurrence and is CR or N; X ２ is the same or different at each occurrence and is CR or N; A is the same or different for each occurrence, CR ２ -CR ２ , C.R. ２ -O, CR ２ -NR, C(=O)-O, C(=O)-NR or a group of formula (27): 【Chemistry 8】 (where the dotted bond in each case indicates the point of attachment of the bidentate ancillary ligand L or L' to the structure, and the * indicates the point of attachment to the central trivalent aryl or heteroaryl group of the unit of formula (27)).

9. The compound according to claim 7 or 8, characterized in that V in the compounds of formula (12) and (13) represents one of the structures of formula (36) to (39). 【Chemistry 9】 (wherein the symbols used have the meanings set out in claim 1)

10. A compound according to any one of claims 1 to 9, characterised in that L', which is identical or different on each occurrence, is a bidentate monoanionic ligand.

11. A process for preparing a compound according to any one of claims 1 to 10 by reacting free ligands L and optionally L' with a metal alkoxide of formula (79), a metal ketoketonate of formula (80), a metal halide of formula (81), a dimeric metal complex of formula (82), or a metal complex of formula (83). 【Chemistry 10】 where the symbols M, m, n and R have the meanings according to claim 1, Hal=F, Cl, Br or I, L″ is an alcohol or a nitrile and (Anion) is a non-coordinating anion.

12. A formulation comprising at least one compound according to any one of claims 1 to 10 and at least one further compound and / or at least one solvent.

13. Use of a compound according to any one of claims 1 to 10 in an electronic device.

14. An electronic device comprising at least one compound according to any one of claims 1 to 10.

15. 15. An electronic device according to claim 14, which is an organic electroluminescent device, characterized in that a compound according to any one of claims 1 to 10 is used in one or more light-emitting layers in combination with one or more matrix materials.

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