DE102015013381A1 - metal complexes - Google Patents

Abstract

The present invention relates to metal complexes and electronic devices, in particular organic electroluminescent devices containing these metal complexes.

Description

The present invention relates to metal complexes which are suitable for use as emitters in organic electroluminescent devices.

The construction of organic electroluminescent devices (OLEDs) in which organic semiconductors are used as functional materials is described, for example, in US Pat US 4539507 . US 5151629 . EP 0676461 and WO 98/27136 described. Here are often used as the emitting materials organometallic complexes that show phosphorescence instead of fluorescence. For quantum mechanical reasons, up to four times energy and power efficiency is possible using organometallic compounds as phosphorescence emitters. In general, there are still room for improvement in OLEDs that show triplet emission, especially with regard to efficiency, operating voltage and service life.

According to the state of the art, iridium and platinum complexes are used in phosphorescent OLEDs as triplet emitters in particular. However, due to the rarity of the metals iridium and platinum, it would be desirable to conserve resources by having metal complexes with other metals that can be used as emitters in OLEDs.

The object of the present invention is therefore to provide new metal complexes which are suitable as emitters for use in OLEDs. In particular, the object is to provide emitters which do not require the use of iridium and platinum as metals and which exhibit good properties in terms of efficiency, operating voltage, lifetime, color coordinates and / or solubility.

Surprisingly, it has been found that the mono- and polynuclear metal chelate complexes described in more detail below achieve this object and are very well suited for use in an organic electroluminescent device. These metal complexes and organic electroluminescent devices containing these complexes are therefore the subject of the present invention.

wobei der Ligand der Formel (1) über die beiden Stickstoffatome an dasselbe Metallatom M koordiniert und über mindestens ein Phosphoratom an ein Metallatom M koordiniert und für die verwendeten Symbole und Indizes gilt:
M ist bei jedem Auftreten gleich oder verschieden ein Metallatom;
X ist bei jedem Auftreten gleich oder verschieden CR¹ oder N mit der Maßgabe, dass pro Cyclus nicht mehr als zwei Symbole X für N stehen und weiterhin mit der Maßgabe, dass X für C steht, wenn an diese Gruppe X eine Gruppe -(Y)_l-PR₂ bzw. -(Y)_n-PR₂ gebunden ist;
Y ist bei jedem Auftreten gleich oder verschieden eine lineare Alkylengruppe mit 1 bis 4 C-Atomen, die durch einen oder mehrere Reste R² substituiert sein kann, oder eine ortho-verknüpfte Arylen- oder Heteroarylengruppe mit 5 bis 10 aromatischen Ringatomen, die durch einen oder mehrere Reste R² substituiert sein kann;
R, R¹ ist bei jedem Auftreten gleich oder verschieden H, D, F, Cl, Br, I, N(R²)₂, OR², SR², CN, NO₂, OH, COOR², C(=O)N(R²)₂, Si(R₂)₃, B(OR²)₂, C(=O)R², P(=O)(R²)₂, S(=O)R², S(=O)₂R², OSO₂R², eine geradkettige Alkylgruppe mit 1 bis 20 C-Atomen oder eine Alkenyl- oder Alkinylgruppe mit 2 bis 20 C-Atomen oder eine verzweigte oder cyclische Alkylgruppe mit 3 bis 20 C-Atomen, wobei die Alkyl-, Alkenyl- bzw. Alkinylgruppe jeweils mit einem oder mehreren Resten R² substituiert sein kann und wobei eine oder mehrere nicht benachbarte CH₂-Gruppen durch R²C=CR², R²C=N, C≡C, Si(R²)₂, C=O, NR², O, S oder CONR² ersetzt sein können und wobei ein oder mehrere H-Atome durch D, F, Cl, Br, I oder CN ersetzt sein können, oder ein aromatisches oder heteroaromatisches Ringsystem mit 5 bis 40 aromatischen Ringatomen, das jeweils durch einen oder mehrere Reste R² substituiert sein kann; dabei können zwei Reste R, die an dasselbe Phosphoratom binden bzw. zwei benachbarte Reste R¹ auch miteinander ein mono- oder polycyclisches, aliphatisches, aromatisches oder heteroaromatisches Ringsystem bilden;
R² ist bei jedem Auftreten gleich oder verschieden H, D, F, Cl, Br, I, N(R³)₂, OR³, SR³, CN, NO₂, Si(R³)₃, B(OR³)₂, C(=O)R³, P(=O)(R³)₂, S(=O)R³, S(=O)₂R³, OSO₂R³, eine geradkettige Alkylgruppe mit 1 bis 20 C-Atomen oder eine Alkenyl- oder Alkinylgruppe mit 2 bis 20 C-Atomen oder eine verzweigte oder cyclische Alkylgruppe mit 3 bis 20 C-Atomen, wobei die Alkyl-, Alkenyl- oder Alkinylgruppe jeweils mit einem oder mehreren Resten R³ substituiert sein kann und wobei eine oder mehrere nicht benachbarte CH₂-Gruppen durch R³C=CR³, R³C=N, C≡C, Si(R³)₂, C=O, NR³, O, S oder CONR³ ersetzt sein können und wobei ein oder mehrere H-Atome durch D, F, Cl, Br, I, CN oder NO₂ ersetzt sein können, oder ein aromatisches oder heteroaromatisches Ringsystem mit 5 bis 40 aromatischen Ringatomen, das jeweils durch einen oder mehrere Reste R³ substituiert sein kann; dabei können zwei oder mehrere benachbarte Reste R² miteinander ein mono- oder polycyclisches, aliphatisches, aromatisches oder heteroaromatisches Ringsystem bilden;
R³ ist bei jedem Auftreten gleich oder verschieden H, D, F oder ein aliphatischer, aromatischer und/oder heteroaromatischer organischer Rest mit 1 bis 20 C-Atomen, in dem auch ein oder mehrere H-Atome durch F ersetzt sein können; dabei können zwei oder mehrere Substituenten R³ auch miteinander ein mono- oder polycyclisches Ringsystem bilden;
l, m, n sind unabhängig voneinander 0 oder 1;
p, q sind unabhängig voneinander 0 oder 1 mit der Maßgabe, dass p + q = 1 oder 2 ist.The invention thus relates to a metal complex having one or more metals M containing at least one ligand according to the following formula (1),

wherein the ligand of the formula (1) is coordinated via the two nitrogen atoms to the same metal atom M and coordinated via at least one phosphorus atom to a metal atom M and applies to the symbols and indices used:
M is the same or different at each occurrence as a metal atom;
X is the same or different CR ¹ or N on each occurrence, with the proviso that for each cycle there are not more than two symbols X for N and furthermore with the proviso that X stands for C, if a group - (Y ) _l -PR ₂ or - (Y) _n -PR ₂ ;
Y is the same or different at each instance and is a linear alkylene group having 1 to 4 carbon atoms, which is represented by one or more carbon atoms a plurality of radicals R ² may be substituted, or an ortho-linked arylene or heteroarylene group having 5 to 10 aromatic ring atoms, which may be substituted by one or more radicals R ² ;
R, R ¹ is the same or different at each occurrence H, D, F, Cl, Br, I, N (R ² ) ₂ , OR ² , SR ² , CN, NO ₂ , OH, COOR ² , C (= O ) N (R ² ) 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 straight-chain alkyl group having 1 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where the alkyl, alkenyl or alkynyl group can each be substituted by one or more radicals R ² and where one or more nonadjacent CH ₂ groups is represented by R ² C =CR ² , R ² C =N, C≡C, Si (R ² ) ₂ , C = O, NR ² , O, S or CONR ² may be replaced and wherein one or more H atoms may be replaced by D, F, Cl, Br, I or CN, or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, each of which may be substituted by one or more radicals R ² ; two radicals R which bind to the same phosphorus atom or two adjacent radicals R ^{1 can} also together form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system;
R ² is the same or different H, D, F, Cl, Br, I, N (R ³ ) ₂ , OR ³ , SR ³ , CN, NO ₂ , Si (R ³ ) ₃ , B (OR ³ ) ₂ , C (= O) R ³ , P (= O) (R ³ ) ₂ , S (= O) R ³ , S (= O) ₂ R ³ , OSO ₂ R ³ , a straight-chain alkyl group having 1 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, wherein the alkyl, alkenyl or alkynyl group in each case be substituted by one or more radicals R ³ and wherein one or more non-adjacent CH ₂ groups can be replaced by R ³ C =CR ³ , R ³ C =N, C≡C, Si (R ³ ) ₂ , C =O, NR ³ , O, S or CONR ³ and wherein one or more H atoms can be replaced by D, F, Cl, Br, I, CN or NO ₂ , or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, each by one or more radicals R ³ may be substituted; two or more adjacent radicals R ^{2 may} together form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system;
R ³ is the same or different at each occurrence, H, D, F or an aliphatic, aromatic and / or heteroaromatic organic radical having 1 to 20 carbon atoms, in which also one or more H atoms may be replaced by F; two or more substituents R ^{3 may} also together form a mono- or polycyclic ring system;
l, m, n are independently 0 or 1;
p, q are independently 0 or 1, with the proviso that p + q = 1 or 2.

According to the invention, the ligand of the formula (1) coordinates via a neutral nitrogen atom of the heteroaromatic six-membered ring and an anionic nitrogen atom of the heteroaromatic five-membered ring to the same metal atom. Furthermore, the ligand has at least one of the groups - (Y) _l -PR ₂ and / or - (Y) _n -PR ₂ , wherein the phosphorus coordinates to a metal atom, this metal atom being either the same metal atom to which the two Coordinate nitrogen atoms, or is another metal atom. When the phosphorus coordinates to the same metal atom, to which the two nitrogen atoms also coordinate, mononuclear complexes are formed, ie, complexes containing only one metal atom. When the phosphorus coordinates to another metal atom, dinuclear or polynuclear complexes are formed, ie, complexes containing two or more metal atoms, where the metal atoms may be the same or different. Furthermore, in polynuclear complexes, the nitrogen atom of the heteroaromatic five-membered ring can simultaneously coordinate to two metals M.

Furthermore, one or more further ligands can be bound or coordinated to the metal atom or the metal atoms in the metal complexes according to the invention.

In the following description, the terms "metal complex" and "complex" are used interchangeably.

An aryl group for the purposes of this invention contains 6 to 40 carbon atoms; For the purposes of this invention, a heteroaryl group contains 2 to 40 C atoms and at least one heteroatom, with the proviso that the sum of C atoms and heteroatoms gives at least 5. The heteroatoms are preferably selected from N, O and / or S. Preferably, the heteroaryl group contains 1, 2 or 3 heteroatoms, of which not more than one is selected from O or S. Here, under an aryl group or heteroaryl group either a simpler aromatic Cyclus, ie benzene, or a simple heteroaromatic cycle, for example pyridine, pyrimidine, thiophene, etc., or a fused aryl or heteroaryl group, for example naphthalene, anthracene, phenanthrene, quinoline, isoquinoline, etc., understood.

An aromatic ring system in the sense of this invention contains 6 to 60 carbon atoms in the ring system. A heteroaromatic ring system in the sense of this invention contains 1 to 60 C atoms and at least one heteroatom in the ring system, with the proviso that the sum of C atoms and heteroatoms gives at least 5. The heteroatoms are preferably selected from N, O and / or S. An aromatic or heteroaromatic ring system in the sense of this invention is to be understood as meaning a system which does not necessarily contain only aryl or heteroaryl groups but in which also several aryl or heteroaryl groups a non-aromatic moiety (preferably less than 10% of the atoms other than H), such as e.g. As a C, N or O atom or a carbonyl group, may be interrupted. For example, systems such as 9,9'-spirobifluorene, 9,9-diarylfluorene, triarylamine, diaryl ethers, stilbene, etc. are to be understood as aromatic ring systems in the context of this invention, and also systems in which two or more aryl groups, for example by a linear or cyclic alkyl group or interrupted by a silyl group. Furthermore, systems in which two or more aryl or heteroaryl groups directly are bound together, such. As biphenyl or terphenyl, also be understood as an aromatic or heteroaromatic ring system.

A cyclic alkyl group in the context of this invention is understood as meaning a monocyclic, a bicyclic or a polycyclic group. If several substituents form an aliphatic ring system with one another, the term "aliphatic ring system" for the purposes of the present invention also includes heteroaliphatic ring systems.

In the context of the present invention, a C ₁ - to C ₄₀ -alkyl group in which individual H atoms or CH ₂ groups may be substituted by the abovementioned groups, for example the radicals 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, neo -pentyl, cyclopentyl, n Hexyl, s -hexyl, t -hexyl, 2-hexyl, 3-hexyl, neo-hexyl, cyclohexyl, 1-methylcyclopentyl, 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-hex-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-decyl 1-yl, 1,1-diethyl-n-dodec-1-yl, 1,1-diethyl-n-tetradec-1-yl, 1,1-diethyln-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. An alkenyl group is understood as meaning, for example, ethenyl, propenyl, butenyl, pentenyl, cyclopentenyl, hexenyl, cyclohexenyl, heptenyl, cycloheptenyl, octenyl, cyclooctenyl or cyclooctadienyl. By an alkynyl group is meant, for example, ethynyl, propynyl, butynyl, pentynyl, hexynyl, heptynyl or octynyl. A C ₁ - to C ₄₀ -alkoxy group is understood as meaning, for example, methoxy, trifluoromethoxy, ethoxy, n-propoxy, i-propoxy, n-butoxy, i-butoxy, s-butoxy, t-butoxy or 2-methylbutoxy.

By an aromatic or heteroaromatic ring system having 5-60 aromatic ring atoms, which may be substituted in each case with the abovementioned radicals and which may be linked via any positions on the aromatic or heteroaromatic, are understood, for example, groups which are derived from benzene, naphthalene , Anthracene, benzanthracene, phenanthrene, benzophenanthrene, pyrene, chrysene, perylene, fluoranthene, benzfluoranthene, naphthacene, pentacene, benzopyrene, biphenyl, biphenylene, terphenyl, terphenylene, fluorene, spirobifluorene, dihydrophenanthrene, 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, phenanthride in, benzo-5,6-quinoline, benzo-6,7-quinoline, benzo-7,8-quinoline, phenothiazine, phenoxazine, pyrazole, indazole, imidazole, benzimidazole, naphthimidazole, phenanthrimidazole, pyrimididazole, pyrazine imidazole, quinoxaline imidazole, oxazole, Benzoxazole, naphthoxazole, anthroxazole, phenanthroxazole, isoxazole, 1,2-thiazole, 1,3-thiazole, benzothiazole, pyridazine, benzopyridazine, pyrimidine, benzpyrimidine, quinoxaline, 1,5-diazaanthracene, 2,7-diazapyrene, 2,3- Diazapyrene, 1,6-diazapyrene, 1,8-diazapyrene, 4,5-diazapyrene, 4,5,9,10-tetraazaperylene, pyrazine, phenazine, phenoxazine, phenothiazine, fluorubin, naphthyridine, azacarbazole, benzocarboline, phenanthroline, 1, 2,3-triazole, 1,2,4-triazole, benzotriazole, 1,2,3-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.

Preferably, the metal complexes of the invention are characterized in that they are not charged, d. H. electrically neutral. This is achieved in a simple way by selecting the charge of all ligands to compensate for the charge of all complexed metal atoms.

Apart from the ligand of the formula (1), it is also possible for further co-ligands to be coordinated to the metal in the metal complexes according to the invention. The coordination number preferably corresponds overall to the usual coordination number for this metal. This is known to the skilled person. For example, this is three or four for Cu (I).

The metal complexes of the invention contain one or more metal atoms M, which may be the same or different. Preference is given to transition metals without lanthanides and actinides or to main group metals, in particular transition metals without lanthanides or actinides. preferred Metals are the same or different at each occurrence selected from the group consisting of Ir, Pt, Cu, Ag, Au, Zn and Al. Particularly preferably, the metal M is Cu.

In the following, preferred embodiments of the ligand of the formula (1) are described.

In a preferred embodiment of the invention, a maximum of one symbol X per cycle stands for N and the other symbols X stand for CR ¹ with the proviso that X stands for C, if to this group X a group - (Y) _l -PR ₂ resp - (Y) _n -PR _{2 is} bonded. More preferably, all of the symbols X are CR ^1, with the proviso that X is C when a group - (Y) ₁ -PR ₂ or - (Y) _n -PR _{2 is} bonded to this group X.

wobei die verwendeten Symbole und Indizes die oben genannten Bedeutungen aufweisen und für p = 0 an das entsprechende Kohlenstoffatom des Pyridins bzw. für q = 0 an das entsprechende Kohlenstoffatom des Pyrrols noch ein Rest R¹ gebunden sein kann.Thus, it is more preferably a ligand of the following formula (1a)

where the symbols and indices used have the abovementioned meanings and, for p = 0, the radical R ¹ may be bonded to the corresponding carbon atom of the pyridine or, for q = 0, to the corresponding carbon atom of the pyrrole.

In a further preferred embodiment of the invention, Y is the same or different on each occurrence, a linear Alkyengruppe having 1, 2 or 3 C-atoms, which may be substituted by one or more radicals R ² , or an ortho-linked arylene or heteroaryl group 6 aromatic ring atoms, which may be substituted by one or more radicals R ² . Y is particularly preferably identical or different on each occurrence and is an alkylene group having 1 or 2 C atoms, which may be substituted by one or more radicals R ² , but is preferably unsubstituted, or an ortho-linked phenylene group represented by one or more radicals R ² may be substituted, but is preferably unsubstituted.

Furthermore, the radical R, which is bonded to the phosphorus atom, preferably identically or differently selected on each occurrence from the group consisting of N (R ² ) ₂ , OR ² , a straight-chain alkyl group having 1 to 10 carbon atoms or a Alkenyl group having 2 to 10 carbon atoms or a branched or cyclic alkyl group having 3 to 10 carbon atoms, wherein the alkyl, alkenyl or alkynyl group may be substituted by one or more radicals R ² and wherein one or more non-adjacent CH ₂ groups may be replaced by O and wherein one or more H atoms may be replaced by F, or an aromatic or heteroaromatic ring system having 5 to 20 aromatic ring atoms, each of which may be substituted by one or more radicals R ² ; In this case, two radicals R, which bind to the same phosphorus atom, also together form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system. With particular preference, the radical R at each occurrence is the same or different selected from the group consisting of OR ² , a straight-chain alkyl group having 1 to 5 C atoms or a branched or cyclic alkyl group having 3 to 5 C atoms, wherein the alkyl group in each case with one or more radicals R ² may be substituted and wherein one or more H atoms may be replaced by F, or an aromatic or heteroaromatic ring system having 5 to 20 aromatic ring atoms, each of which may be substituted by one or more radicals R ² ; In this case, two radicals R, which bind to the same phosphorus atom, also together form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system. With very particular preference, the radical R at each occurrence is identically or differently selected from the group consisting of an aromatic or heteroaromatic ring system having 6 to 20 aromatic ring atoms, which may be substituted by one or more radicals R ^{2 in} each case; In this case, two radicals R, which bind to the same phosphorus atom, also together form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system. Examples of suitable aromatic or heteroaromatic ring systems which may be bonded to the phosphorus as group R are phenyl, biphenyl, terphenyl and naphthyl.

Furthermore, the radical R ^{1 is} preferably identically or differently selected on each occurrence from the group consisting of H, D, F, OR ² , CN, a straight-chain alkyl group having 1 to 10 C atoms or an alkenyl group having 2 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms, wherein the alkyl or alkenyl group may be substituted by one or more R ² each and wherein one or more non-adjacent CH ₂ groups may be replaced by O and wherein one or more H atoms may be replaced by D or F, or an aromatic or heteroaromatic ring system having from 5 to 24 aromatic ring atoms, each of which may be substituted by one or more R ² ; Two adjacent radicals R ¹ can also form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system. With particular preference, the radical R ¹ on each occurrence is identically or differently selected from the group consisting of H, F, a straight-chain alkyl group having 1 to 5 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms, where the alkyl group each may be substituted with one or more radicals R ² and wherein one or more H atoms may be replaced by F, or an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, each of which may be substituted by one or more radicals R ² ; Two adjacent radicals R ¹ can also form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system.

Furthermore, the radical R ^{2 is} preferably identically or differently selected on each occurrence from the group consisting of H, D, F, a straight-chain alkyl group having 1 to 10 C atoms or a branched or cyclic alkyl group having 3 to 10 C atoms, where the alkyl group may be substituted in each case by one or more radicals R ³ , or an aromatic or heteroaromatic ring system having from 6 to 14 aromatic ring atoms, each of which may be substituted by one or more radicals R ³ ; It can have two or more adjacent R ² radicals together form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system. With particular preference, the radical R ² on each occurrence is identically or differently selected from the group consisting of H, a straight-chain alkyl group having 1 to 5 C atoms or a branched or cyclic alkyl group having 3 to 5 C atoms or an aromatic or heteroaromatic ring system with 6 to 12 aromatic ring atoms, which may each be substituted by one or more radicals R ³ , but is preferably unsubstituted; two or more adjacent radicals R ^{2 may} together form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system.

Particularly preferably, the preferences listed above occur simultaneously. Thus, with particular preference for the metal complexes according to the invention:
X is the same or different CR ¹ or N on each occurrence, with at most one symbol X per cycle for N, with the proviso that X stands for C, if to this group X a group - (Y) _l -PR ₂ resp - (Y) _n -PR _{2 is} attached;
Y is the same or different at each occurrence, a linear Alkyengruppe having 1, 2 or 3 C atoms, which may be substituted by one or more radicals R ² , or an ortho-linked arylene or heteroaryl group having 6 aromatic ring atoms, by a or a plurality of radicals R ² may be substituted;
R is the same or different at each occurrence selected from the group consisting of N (R ² ) ₂ , OR ² , a straight-chain 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, wherein the alkyl, alkenyl or alkynyl group may each be substituted by one or more R ² groups and wherein one or more non-adjacent CH ₂ groups may be replaced by O and wherein one or more H atoms may be replaced by F, or an aromatic or heteroaromatic ring system having 5 to 20 aromatic ring atoms, each of which may be substituted by one or more radicals R ² ; two radicals R, which bind to the same phosphorus atom, can also together form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system;
R ¹ is the same or different at each instance selected from the group consisting of H, D, F, OR ² , CN, a straight-chain 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, wherein the alkyl or alkenyl group may be substituted by one or more radicals R ² and wherein one or more non-adjacent CH ₂ groups may be replaced by O and wherein one or more H Atoms can be replaced by D or F, or an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, each of which may be substituted by one or more radicals R ² ; two adjacent radicals R ^{1 may} also together form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system;
R ² is the same or different at each occurrence selected from the group consisting of H, D, F, a straight-chain alkyl group having 1 to 10 carbon atoms or a branched or cyclic alkyl group having 3 to 10 carbon atoms, wherein the alkyl group in each case with one or more radicals R ³ may be substituted, or an aromatic or heteroaromatic ring system having 6 to 14 aromatic ring atoms, each of which may be substituted by one or more radicals R ³ ; two or more adjacent radicals R ^{2 may} together form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system.

With very particular preference for the metal complexes according to the invention:
X is the same or different CR ¹ each occurrence, with the proviso that X is C when linked to this group X is a group - (Y) ₁ -PR ₂ or - (Y) _n -PR ₂ , respectively;
Y is the same or different at each instance and is an alkylene group having 1 or 2 C atoms, which may be substituted by one or more radicals R ² , but is preferably unsubstituted, or an ortho-linked phenylene group represented by one or more radicals R ² may be substituted, but is preferably unsubstituted;
R is the same or different at each occurrence selected from the group consisting of OR ² , a straight-chain alkyl group having 1 to 5 carbon atoms or a branched or cyclic alkyl group having 3 to 5 carbon atoms, wherein the alkyl group in each case with one or more radicals R ² may be substituted and wherein one or more H atoms may be replaced by F, or an aromatic or heteroaromatic ring system having 5 to 20 aromatic ring atoms, each of which may be substituted by one or more radicals R ² ; two radicals R, which bind to the same phosphorus atom, can also together form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system;
R ¹ is the same or different at each instance selected from the group consisting of H, F, a straight-chain alkyl group having 1 to 5 carbon atoms or a branched or cyclic alkyl group having 3 to 10 carbon atoms, wherein the alkyl group in each case with one or a plurality of R ² may be substituted and wherein one or more H atoms may be replaced by F, or an aromatic or heteroaromatic ring system having 6 to 24 aromatic ring atoms, each of which may be substituted by one or more R ² ; two adjacent radicals R ^{1 may} also together form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system;
R ² in each occurrence is identically or differently selected from the group consisting of H, a straight-chain alkyl group having 1 to 5 C atoms or a branched or cyclic alkyl group having 3 to 5 C atoms or an aromatic or heteroaromatic ring system having 6 to 12 aromatic ring atoms, which may be substituted by one or more radicals R ³ , but is preferably unsubstituted; two or more adjacent radicals R ^{2 may} together form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system.

In a preferred embodiment of the invention, the metal complexes according to the invention are mononuclear metal complexes, the ligand of the formula (1) being a tridentate ligand, ie p = 0 or q = 0. For the formation of mononuclear metal complexes, it is preferred if m = 1 and if, for a ligand with p = 1, the index is 1 = 1 or, for a ligand with q = 1, the index n = 1.

wobei die verwendeten Symbole die oben genannten Bedeutungen aufweisen.Preferred tridentate ligands for the formation of mononuclear complexes are thus the ligands of the following formulas (2) and (3),

wherein the symbols used have the meanings given above.

wobei die verwendeten Symbole die oben genannten Bedeutungen aufweisen.Particularly preferred are the ligands of the following formulas (2a) and (3a),

wherein the symbols used have the meanings given above.

Furthermore, it is possible to generate tetradentate ligands from the ligand of the formulas (2) and (3) or (2a) and (3a) if the group R ¹ which is present in formula (2) or (2a ) is attached to the pyrrole in ortho position to the nitrogen atom or which is bonded in the formula (3) or (3a) to the pyridine in ortho position to the nitrogen atom, is a coordinating group which also coordinates to the metal. The coordinating group may be, for example, a heteroaryl group which coordinates to the metal atom via a neutral or anionic nitrogen atom.

In a further preferred embodiment of the invention, the metal complexes according to the invention are mononuclear metal complexes, the ligand of the formula (1) being a tetradentate ligand, ie p = q = 1. For the formation of mononuclear metal complexes it is preferred if l = m = n = 1.

wobei die verwendeten Symbole die oben genannten Bedeutungen aufweisen.Preferred tridentate ligands for the formation of mononuclear complexes are thus the ligands of the following formula (4),

wherein the symbols used have the meanings given above.

wobei die verwendeten Symbole die oben genannten Bedeutungen aufweisen.Particularly preferred are the ligands of the following formula (4a),

wherein the symbols used have the meanings given above.

Examples of suitable ligands of the formulas (2) to (4) are the ligands listed below, where R and R ^{1 have} the abovementioned meanings:

In a further preferred embodiment of the invention, the metal complexes according to the invention are polynuclear metal complexes, in particular binuclear or tetranuclear metal complexes, where the ligand of the formula (1) is a tridentate ligand, ie p = 0 or q = 0, or Ligand of formula (1) is a tetradentate ligand, so p = q = 1.

For the formation of polynuclear complexes it is preferred if m = 0 and / or if for p = 1 the index l = 0 and / or for q = 1 the index n = 0. In particular, with m = 0, which leads to a small bite angle of the ligands, the coordination by the or the phosphane groups on other metals, which leads to polynuclear complexes.

wobei die verwendeten Symbole die oben genannten Bedeutungen aufweisen.Preferred tridentate ligands for the formation of polynuclear complexes are thus the ligands of the following formulas (5) to (10) and preferred tetradentate ligands for the formation of polynuclear complexes are thus the ligands of the following formulas (11) to (13),

wherein the symbols used have the meanings given above.

wobei die verwendeten Symbole die oben genannten Bedeutungen aufweisen.Preferred ligands of the formulas (5) to (13) are the ligands of the following formulas (5a) to (13a),

wherein the symbols used have the meanings given above.

Examples of suitable ligands of the formulas (5) to (13) are the ligands listed below, where R and R ^{1 have} the abovementioned meanings:

Examples of suitable ligands according to formula (1) are the structures listed in the following table.

wobei die verwendeten Symbole und Indizes die oben genannten Bedeutungen aufweisen und je nach Metall M und Struktur des Liganden der Formel (1) auch noch weitere Liganden an M koordinieren können.In mononuclear complexes, both nitrogen atoms of the ligand of the formula (1) and the phosphine group or both phosphine group in ligands having two phosphine groups coordinate to the same metal atom, so that complexes of the following formula (14) result,

where the symbols and indices used have the abovementioned meanings and, depending on the metal M and structure of the ligand of the formula (1), it is also possible to coordinate further ligands to M.

In polynuclear complexes, both nitrogen atoms of the ligands of formula (1) each coordinate to the same metal atom, and one phosphine group or both phosphine groups coordinate to another metal atom. The polynuclear metal complexes are preferably dinuclear or tetranuclear complexes.

wobei die verwendeten Symbole und Indizes die oben genannten Bedeutungen aufweisen und je nach Metall M und Struktur des Liganden der Formel (1) auch noch weitere Liganden an M koordinieren können.The binuclear complexes preferably have a structure represented by the following formula (15) and the tetranuclear complexes have a structure represented by the following formula (16).

where the symbols and indices used have the abovementioned meanings and, depending on the metal M and structure of the ligand of the formula (1), it is also possible to coordinate further ligands to M.

wobei die verwendeten Symbole und Indizes die oben genannten Bedeutungen aufweisen und je nach Metall M und Struktur des Liganden der Formel (1) auch noch weitere Liganden an M koordinieren können. Dabei können in den Strukturen die als unsubstituiert gezeichneten Kohlenstoffatome auch durch Reste R¹ substituiert sein. Diese Substituenten sind der Übersichtlichkeit halber in den Strukturen der Formeln (14a) bis (16a) nicht eingezeichnet.Preferred embodiments of the metal complexes of the formulas (14) to (16) are the structures of the following formulas (14a) to (16a),

where the symbols and indices used have the abovementioned meanings and, depending on the metal M and structure of the ligand of the formula (1), it is also possible to coordinate further ligands to M. In this case, in the structures, the unsubstituted drawn carbon atoms may also be substituted by radicals R ¹ . These substituents are not shown in the structures of the formulas (14a) to (16a) for the sake of clarity.

In the following, preferred co-ligands are described which, besides the ligand of the formula (1), can coordinate to the metal in the metal complexes according to the invention. The co-ligands are preferably neutral, monoanionic, dianionic or trianionic ligands, particularly preferably neutral or monoanionic ligands. In this case, the charge of the co-ligand is preferably selected such that altogether neutral complexes are formed. The co-ligands may be monodentate, bidentate or tridentate and are preferably monodentate, so preferably have a coordination site. Particularly preferably, the co-ligands are monodentate and neutral or monodentate and monoanionic, most preferably monodentate and neutral.

Preferred neutral, monodentate co-ligands are selected from the group consisting of carbon monoxide, nitrogen monoxide, alkyl cyanides, such as. For example, acetonitrile, aryl cyanides, such as. Benzonitrile, Alkyl isocyanides, such as. For example, methylisononitrile, aryl isocyanides, such as. B. benzoisonitrile, amines, such as. For example, trimethylamine, triethylamine, morpholine, phosphines, in particular halogenophosphines, trialkylphosphines, triarylphosphines or alkylarylphosphines, such as. B. trifluorophosphine, trimethylphosphine, tricyclohexylphosphine, tri-tert-butylphosphine, triphenylphosphine, tris (pentafluorophenyl) phosphine, dimethylphenylphosphine, methyldiphenylphosphine, bis (tert-butyl) phenylphosphine, phosphites, such as. For example, trimethyl phosphite, triethyl phosphite, arsines, such as. Trifluorarsine, trimethylarsine, tricyclohexylarsine, tri-tert-butylarsine, triphenylarsine, tris (pentafluorophenyl) arsine, stibines, such as. Trifluorostibine, trimethylstibine, tricyclohexylstibine, tritert-butylstibine, triphenylstibin, tris (pentafluorophenyl) stibine, nitrogen-containing heterocycles, such as. As pyridine, pyridazine, pyrazine, pyrimidine, triazine, and carbenes, in particular Arduengo carbenes.

Preferred monoanionic, monodentate co-ligands are selected from hydride, deuteride, the halides F ^- , Cl ^- , Br and I ^- , alkyl acetylides, such as. As methyl-C≡C ^- , tert-butyl-C≡C ^- , arylacetylidene, such as. As phenyl-C≡C ^- , cyanide, cyanate, isocyanate, thiocyanate, isothiocyanate, aliphatic or aromatic alcoholates, such as. For example, methanolate, ethanolate, propoxide, iso-propanolate, tert-butylate, phenolate, aliphatic or aromatic thioalcoholates such. As methanethiolate, ethanethiolate, propanethiolate, iso-propanethiolate, tert-thiobutylate, thiophenolate, amides, such as. For example, dimethylamide, diethylamide, di-iso-propylamide, morpholide, carboxylates, such as. For example, acetate, trifluoroacetate, propionate, benzoate, aryl groups, such as. Phenyl, naphthyl, and anionic nitrogen-containing heterocycles such as pyrrolidine, imidazolide, pyrazolide. The alkyl groups in these groups are preferably C ₁ -C ₂₀ -alkyl groups, particularly preferably C ₁ -C ₁₀ -alkyl groups, very particularly preferably C ₁ -C ₄ -alkyl groups. An aryl group is also understood to mean heteroaryl groups. These groups are as defined above.

Preferred di- or trianionic co-ligands are O ^2- , S ^2- , carbides, which lead to a coordination of the form RC≡M, and nitrenes, which lead to a coordination of the form RN = M, where R is generally a Substituents is, or N ^3- .

Preferred neutral or mono- or dianionic, bidentate or higher-divalent co-ligands are selected from 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 '-Tetramethyldiaminocyclohexan, imines, such as. B. 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, such as. B. 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-di-iso-propylphenylimino) 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-di-iso-propylphenylimino) butane, 2,3-bis (2,6-bis) tert-butylphenylimino) butane, heterocycles containing two nitrogen atoms, such as. B. 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 -Diketonen, such as. For example, acetylacetone, benzoylacetone, 1,5-diphenylacetylacetone, dibenzoylmethane, bis (1,1,1-trifluoroacetyl) methane, 3-ketonates derived from 3-keto esters, such as. For example, ethyl acetoacetate, carboxylates derived from aminocarboxylic acids, such as. As pyridine-2-carboxylic acid, quinoline-2-carboxylic acid, glycine, N, N-dimethylglycine, alanine, N, N-dimethylaminoalanine, salicyliminates derived from salicylimines, such as. As methylsalicylimine, ethylsalicylimine, phenylsalicylimine, dialcoholates derived from dialcohols, such as. For example, ethylene glycol, 1,3-propylene glycol, dithiolates derived from dithiols, such as. 1,2-ethylenedithiol, 1,3-propylenedithiol, bis (pyrazolylborates), bis (imidazolyl) borates, 3- (2-pyridyl) -diazoles or 3- (2-pyridyl) -triazoles.

The abovementioned preferred embodiments can be combined with one another as desired. In a particularly preferred embodiment of the invention, the abovementioned preferred embodiments apply simultaneously.

Another object of the present invention is a process for preparing the metal complexes of the invention by reacting the corresponding free ligand of formula (1) in protonated or deprotonated form and optionally co-ligands with suitable metal salts, optionally in the presence of a base.

Suitable and preferred copper salts for the preparation of the corresponding copper complexes are Cu mesityl, Cu [N (CH ₂ ) ₄ ] (Cu-pyrrolidine), [Cu (NC-CH ₃ ) ₄ ] BF ₄ . A suitable zinc salt for the preparation of the corresponding zinc complexes is Zn (ClO ₄ ) ₂ .

By this method, optionally followed by purification, such. B. recrystallization or sublimation, the metal complexes according to the invention in high purity, preferably more than 99% (determined by means of ¹ H-NMR and / or HPLC).

For the processing of the compounds according to the invention from the liquid phase, for example by spin coating or by printing processes, formulations of the metal complexes according to the invention are required. These formulations may be, for example, solutions, dispersions or emulsions. It may be preferable to use mixtures of two or more solvents for this purpose. Suitable and preferred solvents are, for example, toluene, anisole, o-, m- or p-xylene, methyl benzoate, mesitylene, tetralin, hexamethylindane, 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, butylbenzoate, cumene, cyclohexanol, cyclohexanone, cyclohexylbenzene, decalin, dodecylbenzene, ethylbenzoate, indane, methylbenzoate, NMP, p-cymene, phenetole, 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 or mixtures of these solvents.

Yet another object of the present invention is therefore a formulation comprising at least one metal complex according to the invention and at least one further compound. The further compound may for example be a solvent. However, the further compound can also be a further organic or inorganic compound which is likewise used in the electronic device, for example a matrix material. This further compound may also be polymeric.

The metal complexes of the invention described above can be used in electronic devices as the active component.

Another object of the invention is therefore the use of a metal complex according to the invention in an electronic device. Yet another object of the present invention is an electronic device containing at least one metal complex according to the invention.

An electronic device is understood to mean a device which contains anode, cathode and at least one layer, this layer containing at least one organic or organometallic compound. The electronic device according to the invention thus contains anode, cathode and at least one layer which contains at least one metal complex according to the invention. Here, preferred electronic devices are selected from the group consisting of organic electroluminescent devices (OLEDs, PLEDs), organic integrated circuits (O-ICs), organic field effect transistors (O-FETs), organic thin film transistors (O-TFTs), organic light-emitting Transistors (O-LETs), organic solar cells (O-SCs), organic optical detectors, organic photoreceptors, organic field quench devices (O-FQDs), light-emitting electrochemical cells (LECs) or organic laser diodes (O-lasers). Particularly preferred are organic electroluminescent devices. Active components are generally the organic or inorganic materials incorporated between the anode and cathode, for example, charge injection, charge transport or charge blocking materials, but especially emission materials and matrix materials. The metal complexes according to the invention exhibit particularly good properties as emission material in organic electroluminescent devices. A preferred embodiment of the invention are therefore organic electroluminescent devices.

The organic electroluminescent device includes cathode, anode and at least one emitting layer. In addition to these layers, they may also contain further layers, for example one or more hole injection layers, hole transport layers, hole blocking layers, electron transport layers, electron injection layers, exciton blocking layers, electron blocking layers, charge generation layers and / or organic or inorganic p / n junctions. It is possible that one or more hole transport layers are p-doped, for example, with metal oxides such as MoO ₃ or WO ₃ or with (per) fluorinated electron-deficient aromatics, and / or that one or more Electron transport layers are n-doped. Likewise, interlayers may be introduced between two emitting layers which, for example, have an exciton-blocking function and / or control the charge balance in the electroluminescent device. It should be noted, however, that not necessarily each of these layers must be present.

In this case, the organic electroluminescent device may contain an emitting layer, or it may contain a plurality of emitting layers. If several emission layers are present, they preferably have a total of a plurality of emission maxima between 380 nm and 750 nm, so that overall white emission results, ie in the emitting layers different emitting compounds are used, which can fluoresce or phosphoresce. Particular preference is given to three-layer systems, the three layers showing blue, green and orange or red emission (for the basic structure see, for example, US Pat. WO 2005/011013 ) or systems which have more than three emitting layers. It may also be a hybrid system wherein one or more layers fluoresce and one or more other layers phosphoresce.

The organic electroluminescent device can be used as a display or for general lighting purposes.

In a preferred embodiment of the invention, the organic electroluminescent device contains the metal complex according to the invention as an emitting compound in one or more emitting layers.

When the metal complex according to the invention is used as the emitting compound in an emitting layer, it is preferably used in combination with one or more matrix materials. The mixture of the metal complex and the matrix material contains between 0.1 and 99 wt .-%, preferably between 1 and 90 wt .-%, particularly preferably between 3 and 40 wt .-%, in particular between 5 and 15 wt .-% of the metal complex based on the total mixture of emitter and matrix material. Accordingly, the mixture contains between 99.9 and 1 wt .-%, preferably between 99 and 10 wt .-%, particularly preferably between 97 and 60 wt .-%, in particular between 95 and 85 wt .-% of the matrix material based on the total mixture Emitter and matrix material.

As matrix material, it is generally possible to use all materials known for this purpose according to the prior art. Preferably, the triplet level of the matrix material is higher than the triplet level of the emitter. Suitable matrix materials for the metal complexes according to the invention are ketones, phosphine oxides, sulfoxides and sulfones, eg. B. according to WO 2004/013080 . WO 2004/093207 . WO 2006/005627 or WO 2010/006680 , Triarylamines, carbazole derivatives, e.g. B. CBP (N, N-Biscarbazolylbiphenyl), m-CBP or in WO 2005/039246 . US 2005/0069729 . JP 2004/288381 . EP 1205527 . WO 2008/086851 or US 2009/0134784 disclosed carbazole derivatives, indolocarbazole derivatives, e.g. B. according to WO 2007/063754 or WO 2008/056746 , Indenocarbazole derivatives, e.g. B. according to WO 2010/136109 or WO 2011/000455 , Azacarbazoles, e.g. B. according to EP 1617710 . EP 1617711 . EP 1731584 . JP 2005/347160 , bipolar matrix materials, e.g. B. according to WO 2007/137725 , Silane, z. B. according to WO 2005/111172 , Azaborole or Boronester, z. B. according to WO 2006/117052 , Diazasilolderivete, z. B. according to WO 2010/054729 , Diazaphospholderivate, z. B. according to WO 2010/054730 , Triazine derivatives, e.g. B. according to WO 2010/015306 . WO 2007/063754 or WO 2008/056746 , Zinc complexes, e.g. B. according to EP 652273 or WO 2009/062578 , Dibenzofuran derivatives, e.g. B. according to WO 2009/148015 , or bridged carbazole derivatives, e.g. B. according to US 2009/0136779 . WO 2010/050778 . WO 2011/042107 or WO 2011/088877 ,

It may also be 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 an aromatic ketone, a triazine derivative or a phosphine oxide derivative with a triarylamine derivative or a carbazole derivative as a mixed matrix for the metal complex according to the invention. Also preferred is the use of a mixture of a charge-transporting matrix material and an electrically inert matrix material, which is not or not significantly involved in charge transport, such. In WO 2010/108579 described.

The metal complexes according to the invention can also be used in other functions in the electronic device, for example as hole transport material in a hole injection or transport layer, as charge generation material, as electron blocking material, as hole blocking material or as Elektronentranportmaterial. Likewise, the complexes according to the invention can be used as matrix material for other phosphorescent metal complexes in an emitting layer.

As the cathode, low work function metals, metal alloys or multilayer structures of various metals are preferable, such as alkaline earth metals, alkali metals, main group metals or lanthanides (eg, Ca, Ba, Mg, Al, In, Mg, Yb, Sm, etc.). , Also suitable are alloys of an alkali or alkaline earth metal and silver, for example an alloy of magnesium and silver. In multilayer structures, it is also possible, in addition to the metals mentioned, to use further metals which have a relatively high work function, such as, for example, B. Ag, which then usually combinations of metals, such as Mg / Ag, Ca / Ag or Ba / Ag are used. It may also be preferred to introduce between a metallic cathode and the organic semiconductor a thin intermediate layer of a material with a high dielectric constant. Suitable examples of these are alkali metal or alkaline earth metal fluorides, but also the corresponding oxides or carbonates (eg LiF, Li ₂ O, BaF ₂ , MgO, NaF, CsF, Cs ₂ CO ₃ , etc.). Likewise suitable for this purpose are organic alkali metal complexes, for. B. Liq (lithium quinolinate). The layer thickness of this layer is preferably between 0.5 and 5 nm.

As the anode, high workfunction materials are preferred. Preferably, the anode has a work function greater than 4.5 eV. Vacuum up. On the one hand, metals with a high redox potential, such as Ag, Pt or Au, are suitable for this purpose. On the other hand, metal / metal oxide electrodes (for example Al / Ni / NiO _x , Al / PtO _x ) may also be preferred. For some applications, at least one of the electrodes must be transparent or partially transparent to allow either the irradiation of the organic material (OSC) or the outcoupling of light (OLED / PLED, O-LASER). 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, for. B. PEDOT, PANI or derivatives of these polymers. It is furthermore preferred if a p-doped hole transport material is applied to the anode as a hole injection layer, wherein suitable p-dopants are metal oxides, for example MoO ₃ or WO ₃ , or (per) fluorinated electron-poor aromatics. Further suitable p-dopants are HAT-CN (hexacyanohexaazatriphenylene) or the compound NPD9 from Novaled. Such a layer simplifies the hole injection in materials with a low HOMO, ie a HOMO of large magnitude.

In the further layers, it is generally possible to use all materials as used in the prior art for the layers, and the person skilled in the art can combine any of these materials in an electronic device with the inventive materials without inventive step.

The device is structured accordingly (depending on the application), contacted and finally hermetically sealed because the life of such devices drastically shortened in the presence of water and / or air.

Further preferred is an organic electroluminescent device, characterized in that one or more layers are coated with a sublimation process. The materials are vapor-deposited in vacuum sublimation systems at an initial pressure of usually less than 10 ^-5 mbar, preferably less than 10 ^-6 mbar. It is also possible that the initial pressure is even lower or even higher, for example less than 10 ^-7 mbar.

Also preferred is an organic electroluminescent device, characterized in that one or more layers are coated with the OVPD (Organic Vapor Phase Deposition) method or with the aid of a carrier gas sublimation. The materials are applied at a pressure between 10 ^-5 mbar and 1 bar. A special case of this process is the OVJP (Organic Vapor Jet Printing) process, in which the materials are applied directly through a nozzle and thus structured (eg. MS Arnold et al., Appl. Phys. Lett. 2008, 92, 053301 ).

Further preferred is an organic electroluminescent device, characterized in that one or more layers of solution, such. B. by spin coating, or with any printing process, such. As screen printing, flexographic printing, offset printing or Nozzle printing, but more preferably LITI (Light Induced Thermal Imaging, thermal transfer printing) or ink-jet printing (ink jet printing) can be produced. For this purpose, soluble compounds are necessary, which are obtained for example by suitable substitution. In particular for the polynuclear metal complexes according to the invention, solution processing is preferred because of the high molecular weight.

The organic electroluminescent device may also be fabricated as a hybrid system by applying one or more layers of solution and depositing one or more other layers. It is thus possible, for example, to apply an emitting layer containing a metal complex according to the invention and a matrix material from solution and then evaporate a hole blocking layer and / or an electron transport layer in vacuo.

These methods are generally known to the person skilled in the art and can be applied by him without problems to organic electroluminescent devices containing the metal complexes according to the invention.

• 1. Organische Elektrolumineszenzvorrichtungen enthaltend die erfindungsgemäßen Verbindungen als emittierende Materialien weisen eine hohe Effizienz und Lebensdauer auf. Insbesondere ist so die Herstellung effizienzter OLEDs unter Vermeidung der seltenen Metalle Iridium und Platin möglich.
• 2. Die erfindungsgemäßen Metallkomplexe sind sehr gut in organischen Lösemitteln, insbesondere in polaren organischen Lösemitteln, löslich. Dies führt zu einer vereinfachten Aufreinigung während der Synthese der Komplexe. Weiterhin können die erfindungsgemäßen Komplexe dadurch zur Herstellung von OLEDs in lösungsprozessierten Verfahren, beispielsweise Druckverfahren, eingesetzt werden.

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

• 1. Organic electroluminescent devices containing the compounds of the invention as emitting materials have a high efficiency and lifetime. In particular, the production of efficient OLEDs while avoiding the rare metals iridium and platinum is possible.
• 2. The metal complexes according to the invention are very soluble in organic solvents, in particular in polar organic solvents. This leads to a simplified purification during the synthesis of the complexes. Furthermore, the complexes according to the invention can thereby be used for the preparation of OLEDs in solution-processed processes, for example printing processes.

The invention is explained in more detail by the following examples without wishing to restrict them thereby. The person skilled in the art can produce further inventive electronic devices from the descriptions without inventive step and thus carry out the invention in the entire claimed area.

Examples:

Unless stated otherwise, the following syntheses are carried out under an inert gas atmosphere in dried solvents. The metal complexes are additionally handled in the absence of light or under yellow light. The solvents and reagents may, for. B. from Sigma-ALDRICH or ABCR.

Ligand synthesis

Example 1: Synthesis of 2- (diphenylphosphino) -6- (1H-pyrrol-2-yl) pyridine ("NNP")

Scheme 1: Representation of the NNP ligand. 1st step: lithiation of 2,6-dibromopyridine and reaction with CIPPh ₂ (according to T. Šmejkal, B. Breit, Angew. Chem. Int. Ed. 47, 311-315, (2008) ). 2nd step: Suzuki Coupling of N-Boc-pyrrol-2-ylboronic acid MIDA ester to 2-bromo-6- (diphenylphosphino) pyridine. 3rd step: Boc deprotection with conc. HCl to the ligand NNP.

In an autoclave, 342.18 mg of 2-bromo-6- (diphenylphosphino) pyridine (1 mmol), 354.3 mg of N-Boc-pyrrol-2-ylboronic acid MIDA ester (1.1 mmol), 11.23 mg [PdOAc ₂ ] (0.05 mmol ) and 41.05 mg SPhos (0.1 mmol) were weighed, rendered inert and 12.5 ml of dioxane and 2 ml of 3 MK ₃ PO ₄ solution (6 mmol) were added dropwise. The autoclave is closed and the contents are stirred at 60 ° C. for 18 h. The resulting Boc-protected product is taken up in 20 ml Et ₂ O and washed three times with H ₂ O, then the aqueous phase extracted three times with 10 ml Et ₂ O, the organic phase dried over MgSO ₄ , filtered off and concentrated in vacuo , Subsequently, the intermediate product is directly Boc-deprotected. For this purpose it is dissolved in 7.24 ml of dichloromethane, 2.41 ml of HCl (conc.) Are added and the mixture is stirred for 24 hours at room temperature. It is then neutralized with 20 ml of NaHCO ₃ solution. The reaction mixture is taken up in 20 ml of dichloromethane and washed three times with H ₂ O, then the aqueous phase extracted three times with 10 ml of dichloromethane, the organic phase dried over MgSO ₄ , filtered off and concentrated in vacuo. The product is obtained after subsequent purification over a silica gel column (ethyl acetate / n-hexane 3: 7, R _f = 0.93) as a white solid. Yield of coupling 78%, yield of Boc deprotection 47%. To increase this, both the coupling and the deprotection can be performed in a microwave. Deprotection is carried out using 0.6 M NaOMe solution (in MeOH) with THF as the solvent under pressure at 150 ° C. ¹ H NMR (DCM-d ₂ , 400.13 MHz): δ 9.41 (bs, 1H), 7.54 (m, 1H), 7.44-7.59 (m, 5H), 7.39-7.42 (m, 6H), 6.91 (m, 1H), 6.83 (m, 1H), 6.74 (m, 1H), 6.28 (m, 1H). ¹³ C NMR (DCM-d ₂ , 100.13 MHz): δ 162.81, 151.07, 137.27, 136.80, 134.77, 131.84, 129.59, 129.08, 125.52, 120.50, 117.12, 110.79, 107.85. ³¹ P { ¹ H) NMR (DCM-d ₂ , 161.98 MHz): δ -3.87 (s).

complex syntheses

Example 2: Synthesis of [Cu ₂ (NNP) ₂ (PPh ₃ )]

In air, 32.84 mg NNP (0.1 mmol) (ligand from Example 1) and 26.23 mg PPh ₃ (0.1 mmol), wherein only half of the PPh ₃ complexed, weighed and introduced into a glovebox. There 18.09 mg mesityl copper (0.099 mmol) and 3 ml of toluene are added. The reaction mixture is stirred for 1 h at room temperature. The product is precipitated from the previously filtered reaction mixture with n-hexane and washed three times with n-hexane. It is then concentrated in vacuo. The product is obtained as a yellow solid. Yield: 74%. Single crystals are obtained by overlaying a toluene solution with n-hexane. ¹ H NMR (DCM-d ₂ , 400.13 MHz): δ 7.50 (m, 2H), 7.39 (m, 2H), 7.19-7.27 (m, 8H), 6.95-7.12 (m, 27H), 6.83 (m, 2H), 6.38 (m, 2H), 6.26 (m, 2H), 6.14 (m, 2H). ¹³ C { ¹ H} NMR (DCM-d ₂ , 100.13 MHz): δ 155.38, 138.33, 137.15, 134.34, 134.28, 134.11, 133.97, 133.77, 130.25, 129.74, 129.02, 128.75, 123.13, 123.04, 118.82, 111.59, 110.11. ³¹ P { ¹ H} NMR (DCM-d ₂ , 161.98 MHz): δ 4.31 (s, NNP, 2P), -1.99 (s, PPh ₃ , 1P). Elemental analysis calculated (%) for C ₆₀ H ₄₇ Cu ₂ N ₄ P ₃ (1044.06 g / mol): C, 69.02; H, 4.54; N, 5.37. Found: C, 68.99; H, 4.54; N, 5.33. The single crystal structure of the compound is in 1 shown.

Example 3: Synthesis of [Cu (NNP)] ₄

In air, 32.84 mg NNP (0.1 mmol) (ligand from Example 1) are weighed and introduced into a glovebox. There 18.09 mg mesityl copper (0.099 mmol) and 3 ml of toluene are added. The reaction mixture is stirred for 1 h at room temperature. The product is precipitated from the previously filtered reaction mixture with n-hexane and washed three times with n-hexane. It is then concentrated in vacuo. The product is obtained as a yellow solid. Yield: 86%. Single crystals are obtained by overlaying a toluene solution with n-hexane. ¹ H NMR (DCM-d ₂ , 400.13 MHz): δ 7.53 (m, 4H), 7.46 (m, 4H), 7.39 (m, 8H), 7.17-7.28 (m, 32H), 6.77-6.80 (m, 8H), 6.38 (m, 4H), 6.21 (m, 4H). ¹³ C { ¹ H} NMR (DCM-d ₂ , 100.13 MHz): δ 158.31, 154.64, 138.60, 138.16, 134.05, 133.86, 132.61, 130.73, 129.42, 124.11, 119.27, 112.01, 110.37. ³¹ P { ¹ H} NMR (DCM-d ₂ , 161.98 MHz): δ -10.18 (s). Elemental analysis calculated (%) for C ₈₄ H ₆₄ Cu ₄ N ₈ P ₄ + toluene (1563.54 g / mol): C, 66.01; H, 4.38; N, 6.77. Found: C, 66.18; H, 4.41; N, 6.42. The single crystal structure of the compound is in 2 shown.

Example 4 Luminescence Properties of the Complexes of Example 2 and Example 3

The photoluminescence spectra of the compounds [Cu ₂ (NNP) ₂ (PPh ₃ )] from Example 2 and [Cu (NNP)] ₄ from Example 3 are described in 3 displayed. Both complexes show as pure substances luminescence with almost identical emission. [Cu ₂ (NNP) ₂ (PPh ₃ )] has an emission maximum at 596 nm with a small shoulder at 544 nm, which slightly broadens the band shape compared to that of [Cu (NNP)] ₄ . [Cu (NNP)] ₄ has an emission maximum at 584 nm, ie, a hypnochromic shift of 12 nm. Here at 606 nm a small shoulder can be seen. The shapes of the bands indicate, by virtue of their shoulders, that the emissions consist of overlaps of at least two transitions. These transitions appear to be very similar in both complexes. In addition, the slowly rising but steeply sloping waveform for emission speaks from a long-lived state, so presumably phosphorescence.

Device Examples

Production of the OLEDs (Solution-Processed Devices) The complexes according to the invention can be processed from solution. The production of such components is based on the production of polymeric light-emitting diodes (PLEDs), which has already been described many times in the literature (for example in US Pat WO 2004/037887 ). The structure is composed of substrate / ITO / PEDOT (80 nm) / interlayer (80 nm) / emission layer (60 nm) / ETL (30 nm) / cathode. For this purpose, substrates from Technoprint (Sodalimeglas) are used, to which the ITO structure (indium tin oxide, a transparent, conductive anode) is applied. The substrates are cleaned in the clean room with DI water and a detergent (Deconex 15 PF) and then activated by a UV / ozone plasma treatment. Thereafter, an 80 nm layer of PEDOT (PEDOT is a polythiophene derivative (Baytron P VAI 4083sp.) From HC Starck, Goslar, which is supplied as aqueous dispersion) is also applied by spin coating in the clean room as buffer layer. The required spin rate depends on the degree of dilution and the specific spin coater geometry (typically 80 nm: 4500 rpm). To remove residual water from the layer, the substrates are baked for 10 minutes at 180 ° C on a hot plate. The interlayer used is for hole injection. Alternatively, the interlayer can also be replaced by one or more layers, which merely have to fulfill the condition that they are not replaced by the downstream processing step of the EML deposition from solution. To produce the emission layer (EML), the emitters according to the invention are dissolved together with the matrix materials in toluene. The typical solids content of such solutions is between 16 and 25 g / L, if, as here, the typical for a device layer thickness of 60 nm is to be achieved by spin coating. The solution-processed devices contain an emission layer (polystyrene: M1: M2: emitter) (25%: 25%: 40%: 10%). The emission layer is spin-coated in an inert gas atmosphere, in this case argon, and baked at 130 ° C. for 30 minutes. Then an electron transport layer (ETL) is evacuated in vacuum (ETM1: ETM2) (50%: 50%) evaporated. Finally, a cathode made of aluminum (100 nm) (high-purity metals from Aldrich, evaporation systems from Lesker, etc., typical vapor pressure 5 × 10 ^-6 mbar) is applied by evaporation. Optionally, first a lock blocking layer and then an electron transport layer and then only the cathode (eg Al or LiF / Al) can be evaporated in vacuo. To protect the device from air and humidity, the device is finally encapsulated and then characterized. The mentioned OLED examples are not yet optimized. Table 1 summarizes the data obtained, in Table 2 the materials used are listed. Table 1: Results with solution processed materials Ex. Emitter Ex. EQE (%) 500 cd / m ² Voltage (V) 500 cd / m ² CIE x / y 500 cd / m ² D-Ex. 1 Example 1 5.7 5.9 0.47 / 12:48 D-Ex. 2 Ex. 2 8.6 6.1 0.49 / 12:45 Table 2: Structural formulas of the materials used

Description of the figures

1: single crystal structure of the compound from example 2 (ORTEP representation with 50% probability level)

The hydrogen atoms are not shown for clarity, and the phenyl groups on the phosphor are shown only as spheres. The structure shows a Cu atom in trigonal planar (Cu1) and tetrahedral (Cu2) environments. Both coordinations are slightly distorted. The NNP ligand coordinates with each of two nitrogen atoms to a Cu atom. The two phosphine arms (P1 and P2) coordinate to the other Cu atom and bridge the two fragments. Steric allows for a fourth coordination site at one of the two Cu centers, which is coordinated by a free PPh ₃ (P3). Both NNP ligands are almost perfectly planar, so there is no torsion of the heterocycles. The bond lengths and angles show no significant abnormalities. The Cu1-Cu2 distance of 3.4426 (5) Å is too large for a significant interaction of the two metal centers. Selected bond lengths [Å] and angles [°]: Cu1-N1 1.978 (3), Cu1-N2 2.047 (2), Cu1-P1 2.1545 (8), Cu2-N3 2.034 (3), Cu2-N4 2.140 (2) , Cu2-P2 2.2523 (8), Cu2- P3 2.2789 (8), N1-Cu1-N2 82.59 (10), N1-Cu1-P1 125.80 (7), N2-Cu1-P1 151.59 (7), N3-Cu2-N4 81.22 (9), P2-Cu2- P3 127.28 (3), torsion angle [°] around Cu2: 80.423 (65), 79.070 (51), 72.610 (57).

2: single-crystal structure of the compound from Example 3 (ORTEP representation with 50% probability level)

Hydrogen atoms and solvent molecules are not shown for clarity, and the phenyl groups on the phosphor are shown as spheres only. Here, two fragments are bridged, which correspond in principle in each case to the complex [Cu ₂ (NNP) ₂ (PPh ₃ )], but without the single PPh ₃ unit. The coordination to the same is replaced by the bridging η ¹ coordination of a pyrrole unit (N4 and N5). The neighboring C atoms (C22 and C23 or C50 and C51) additionally coordinate η ² to the previously trigonal planar Cu atoms (Cu1 and Cu4). Bridging creates a weak interaction between Cu2 and Cu3, which are 2.8080 (6) Å apart. The distance from Cu1 to Cu2 or Cu3 to Cu4 becomes slightly smaller (3.2746 (7) Å) as compared to [Cu ₂ (NNP) ₂ (PPh ₃ )]. Selected bond lengths [Å] and angles [°]: Cu1-N1 2.005 (3), Cu1-N2 2.043 (3), Cu2-N4 2.070 (3), Cu3-N4 2.254 (3), Cu1-P1 2.1580 (10) , Cu2-Cu3 2.8080 (6), N1-Cu1-N2 83.27 (12), N1-Cu1-P1 120.36 (9), N2-Cu1-P1 147.97 (10), Cu2-N4-Cu3 52.42 (9), torsion angle [°] around Cu2: 87.988 (96), 78.777 (96), 75.15 (12).

3: Photoluminescence spectra of the NNP complexes from Examples 2 and 3 as pure substance

Only the emission is shown since the excitation band extends over a very broad range and has no defined maxima.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 4539507 [0002]
• US 5151629 [0002]
• EP 0676461 [0002]
• WO 98/27136 [0002]
• WO 2005/011013 [0060]
• WO 2004/013080 [0064]
• WO 2004/093207 [0064]
• WO 2006/005627 [0064]
• WO 2010/006680 [0064]
• WO 2005/039246 [0064]
• US 2005/0069729 [0064]
• JP 2004/288381 [0064]
• EP 1205527 [0064]
• WO 2008/086851 [0064]
• US 2009/0134784 [0064]
• WO 2007/063754 [0064, 0064]
• WO 2008/056746 [0064, 0064]
• WO 2010/136109 [0064]
• WO 2011/000455 [0064]
• EP 1617710 [0064]
• EP 1617711 [0064]
• EP 1731584 [0064]
• JP 2005/347160 [0064]
• WO 2007/137725 [0064]
• WO 2005/111172 [0064]
• WO 2006/117052 [0064]
• WO 2010/054729 [0064]
• WO 2010/054730 [0064]
• WO 2010/015306 [0064]
• EP 652273 [0064]
• WO 2009/062578 [0064]
• WO 2009/148015 [0064]
• US 2009/0136779 [0064]
• WO 2010/050778 [0064]
• WO 2011/042107 [0064]
• WO 2011/088877 [0064]
• WO 2010/108579 [0065]
• WO 2004/037887 [0084]

Cited non-patent literature

• MS Arnold et al., Appl. Phys. Lett. 2008, 92, 053301 [0072]
• T. Šmejkal, B. Breit, Angew. Chem. Int. Ed. 47, 311-315, (2008) [0079]

Claims (15)

Metal complex with one or more metals M containing at least one ligand according to formula (1),

wherein the ligand of the formula (1) is coordinated to the same metal atom M via the two nitrogen atoms and coordinated to a metal atom M via at least one phosphorus atom and applies to the symbols and indices used: M is, identically or differently, a metal atom at each occurrence; X is the same or different CR ¹ or N on each occurrence, with the proviso that for each cycle there are not more than two symbols X for N and furthermore with the proviso that X stands for C, if a group - (Y ) _l -PR ₂ or - (Y) _n -PR ₂ ; Y is the same or different at each occurrence, a linear alkylene group having 1 to 4 carbon atoms, which may be substituted by one or more radicals R ² , or an ortho-linked arylene or heteroarylene group having 5 to 10 aromatic ring atoms, by a or a plurality of radicals R ² may be substituted; R, R ¹ is the same or different at each occurrence H, D, F, Cl, Br, I, N (R ² ) ₂ , OR ² , SR ² , CN, NO ₂ , OH, COOR ² , C (= O ) N (R ² ) 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 straight-chain alkyl group having 1 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, where the alkyl, alkenyl or alkynyl group can each be substituted by one or more radicals R ² and where one or more nonadjacent CH ₂ groups is represented by R ² C =CR ² , R ² C =N, C≡C, Si (R ² ) ₂ , C = O, NR ² , O, S or CONR ² may be replaced and wherein one or more H atoms may be replaced by D, F, Cl, Br, I or CN, or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, each of which may be substituted by one or more radicals R ² ; two radicals R which bind to the same phosphorus atom or two adjacent radicals R ^{1 can} also together form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system; R ² is the same or different H, D, F, Cl, Br, I, N (R ³ ) ₂ , OR ³ , SR ³ , CN, NO ₂ , Si (R ³ ) ₃ , B (OR ³ ) ₂ , C (= O) R ³ , P (= O) (R ³ ) ₂ , S (= O) R ³ , S (= O) ₂ R ³ , OSO ₂ R ³ , a straight-chain alkyl group having 1 to 20 C atoms or an alkenyl or alkynyl group having 2 to 20 C atoms or a branched or cyclic alkyl group having 3 to 20 C atoms, wherein the alkyl, alkenyl or alkynyl group in each case be substituted by one or more radicals R ³ and wherein one or more non-adjacent CH ₂ groups can be replaced by R ³ C =CR ³ , R ³ C =N, C≡C, Si (R ³ ) ₂ , C =O, NR ³ , O, S or CONR ³ and wherein one or more H atoms can be replaced by D, F, Cl, Br, I, CN or NO ₂ , or an aromatic or heteroaromatic ring system having 5 to 40 aromatic ring atoms, each by one or more radicals R ³ may be substituted; two or more adjacent radicals R ^{2 may} together form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system; R ³ is the same or different at each occurrence, H, D, F or an aliphatic, aromatic and / or heteroaromatic organic radical having 1 to 20 carbon atoms, in which also one or more H atoms may be replaced by F; two or more substituents R ^{3 may} also together form a mono- or polycyclic ring system; l, m, n are independently 0 or 1; p, q are independently 0 or 1, with the proviso that p + q = 1 or 2. Metal complex according to claim 1, characterized in that it is not charged. Metal complex according to claim 1 or 2, characterized in that the contained metal atoms, which may be the same or different, when the metal complex contains a plurality of metal atoms, are selected from the group consisting of Ir, Pt, Cu, Ag, Au, Zn or Al. Metal complex according to one or more of claims 1 to 3, characterized in that for the symbols used: X is the same or different CR ¹ or N at each occurrence, with a maximum of one symbol X per cycle for N, with the proviso that X is C when a group - (Y) _l -PR ₂ or - (Y) _n -PR _{2 is} bonded to this group X; Y is the same or different on each occurrence selected from the group consisting of linear Alkyengruppen with 1, 2 or 3 C-atoms, which may be substituted by one or more radicals R ² , or ortho-linked arylene or heteroaryl groups having 6 aromatic ring atoms which may be substituted by one or more radicals R ² ; R is the same or different at each occurrence selected from the group consisting of N (R ² ) ₂ , OR ² , a straight-chain 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, wherein the alkyl, alkenyl or alkynyl group may each be substituted by one or more R ² groups and wherein one or more non-adjacent CH ₂ groups may be replaced by O and wherein one or more H atoms may be replaced by F, or an aromatic or heteroaromatic ring system having 5 to 20 aromatic ring atoms, each of which may be substituted by one or more radicals R ² ; In this case, two radicals R, which bind to the same phosphorus atom, also together form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system. R ¹ is the same or different at each instance selected from the group consisting of H, D, F, OR ² , CN, a straight-chain 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, wherein the alkyl or alkenyl group may be substituted by one or more radicals R ² and wherein one or more non-adjacent CH ₂ groups may be replaced by O and wherein one or more H Atoms can be replaced by D or F, or an aromatic or heteroaromatic ring system having 5 to 24 aromatic ring atoms, each of which may be substituted by one or more radicals R ² ; two adjacent radicals R ^{1 may} also together form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system; R ² is the same or different at each occurrence selected from the group consisting of H, D, F, a straight-chain alkyl group having 1 to 10 carbon atoms or a branched or cyclic alkyl group having 3 to 10 carbon atoms, wherein the alkyl group in each case with one or more radicals R ³ may be substituted, or an aromatic or heteroaromatic ring system having 6 to 14 aromatic ring atoms, each of which may be substituted by one or more radicals R ³ ; two or more adjacent radicals R ^{2 may} together form a mono- or polycyclic, aliphatic, aromatic or heteroaromatic ring system. Metal complex according to one or more of Claims 1 to 4, characterized in that the ligand of the formula (1) is a ligand of the formula (1a),

wherein the symbols and indices used have the meanings given in claim 1 and for p = 0 may be bound to the corresponding carbon atom of pyridine or for q = 0 to the corresponding carbon atom of the pyrrole still a radical R ¹ . Metal complex according to one or more of claims 1 to 5, characterized in that it is a mononuclear metal complex and the ligands of the formula (1) are selected from the ligands of the formulas (2), (3) or (4) or that it is a polynuclear metal complex and the ligands of the formula (1) are selected from the ligands of the formulas (5) to (13),

wherein the symbols used have the meanings mentioned in claim 1. Metal complex according to claim 6, characterized in that the ligands of the formulas (2) to (13) are selected from the ligands of the formulas (2a) to (13a),

wherein the symbols used have the meanings mentioned in claim 1. Metal complex according to one or more of claims 1 to 7 according to formula (14), (15) or (16),

wherein the symbols and indices used have the meanings mentioned in claim 1 and can coordinate even more ligands to M. Metal complex according to claim 8, selected from the structures of formulas (14a), (15a) and (16a),

wherein the symbols and indices used have the meanings mentioned in claim 1, can coordinate further ligands to M and the carbon atoms are also substituted by R ¹ . Metal complex according to one or more of claims 1 to 9, characterized in that in addition to the ligands of formula (1) one or more neutral, monodentate co-ligands and / or one or more monoanionic, monodentate co-ligands to one or more metals M coordinate. Process for the preparation of a metal complex according to one or more of Claims 1 to 10 by reaction of the free ligand of the formula (1) in protonated or deprotonated form and optionally co-ligands with a metal salt, if appropriate in the presence of a base. Formulation containing at least one metal complex according to one or more of claims 1 to 10 and at least one further compound, in particular a solvent. Use of a metal complex according to one or more of claims 1 to 10 in an electronic device. Electronic device, in particular selected from the group consisting of organic electroluminescent devices, organic integrated circuits, organic field effect transistors, organic thin film transistors, organic light emitting transistors, organic solar cells, organic optical detectors, organic photoreceptors, organic field quench devices, light emitting electrochemical Cells or organic laser diodes containing at least one metal complex according to one or more of claims 1 to 10. Electronic device according to claim 14, characterized in that it is an organic electroluminescent device and the metal complex according to one or more of claims 1 to 10 is used as an emitting compound in one or more emitting layers.

Images