WO2011026886A1

WO2011026886A1 - Dinuclear metal-carbene complex in oleds

Info

Publication number: WO2011026886A1
Application number: PCT/EP2010/062851
Authority: WO
Inventors: Thomas Strassner; Alexander Poethig
Original assignee: Basf Se; Tu Dresden
Priority date: 2009-09-03
Filing date: 2010-09-02
Publication date: 2011-03-10

Abstract

The invention relates to dinuclear carbene complexes containing Ag, Au, and/or Cu as metal cations, and a method for the production of said dinuclear carbene complexes by bringing compounds that contain the corresponding metal cation in contact with the corresponding ligands or ligand precursors. The invention also relates to OLEDs containing at least one of said dinuclear carbene complexes, a light-emitting layer containing at least one of said dinuclear carbene complexes, OLEDs containing said light-emitting layer, a device selected from the group consisting of stationary screens and mobile screens and illuminating means containing corresponding OLEDs, and the use of said dinuclear carbene complex in OLEDs, particularly as emitters, matrix material, charge transportation material, and/or charge blockers.

Description

The present invention relates to dinuclear carbene complexes, organic light-emitting diodes (OLEDs) containing at least one such dinuclear carbene complex, light-emitting layers containing at least one such dinuclear carbene complex, a device such as stationary or mobile screens or illumination means, containing a corresponding OLED, as well as the use of the dinuclear carbene complexes according to the invention in OLEDs, for example as emitter, matrix material, charge transport material and / or charge blocker.

In Organic Light Emitting Diode (OLED), the property of materials is used to emit light when excited by electrical current. OLEDs are of particular interest as an alternative to cathode ray tubes and liquid crystal displays for the production of flat panel displays. Due to the very compact design and the intrinsically low power consumption, devices containing OLEDs are particularly suitable for mobile applications, eg. B. for applications in cell phones, laptops, etc. Furthermore, white OLEDs offer great advantages over the previously known lighting technologies, in particular a particularly high efficiency.

Numerous materials, for example silver-cation-containing complexes, which emit light when excited by electric current, are proposed in the prior art.

Catalano et al., Journal of Organometallic Chemistry, 690 (2005) 6041-6050 disclose luminescent coordination polymers having Au (I) Ag (I) interactions wherein the metal atoms are stabilized by pyridyl-substituted NHC ligands.

Liu et al., Organometallics 2007, 26, 3660-3667 disclose the synthesis and luminescence of silver cation-containing complexes having short Ag-Ag bonds which are stabilized by functionalized bis (N-heterocyclic carbene) ligands.

Zhou et al., Journal of Organometallic Chemistry 693 (2008), 205-215 disclose the synthesis and characterization of polynuclear silver complexes containing pyrazole-functionalized NHC ligands bearing Ag-Ag and Ag-u interactions. In the complexes according to this document are silver cations by Carbene bonds attached to two pyrazole units. However, these existing pyrazole units are not bridged.

Other complexes containing silver and gold cations are disclosed in Zhou et al., Organometallics 2007, 26, 2742-2746. For example, these complexes have four silver cations attached to pyrazole moieties via carbene bonds. The pyrazole units are bridged by simple -CH ₂ bonds. Further bonds are between silver and the lone pair of nitrogen atoms. Similar complexes, but with gold cations as metal atoms, are disclosed in Hemmert et al., Dalton Trans., 2009, 340-352.

Chen et al., Inorganic Chemistry Communications 11 (2008), 404-408 disclose linearly aligned Ag ₃ complexes stabilized by 1, 8-naphthyridine-bridged N-heterocyclic carbenes. In these complexes silver cations attached to two imidazole derivatives via carbene bonds are present. In each case two of the present imidazole units are linked via naphthyridine systems.

Other silver and / or gold cation-containing complexes containing carbene linkaged pyrazole derivatives are described in Ray et al., Inorganic Chemistry 2008, 47, 230-240, Catalano et al., Inorganic Chemistry 2007, 46, 5608 - 5615, Catalano et al., Inorganic Chemistry, 2004, 43, 5714-5724 and Catalano et al., Inorganic Chemistry 2005, 44, 6558-6566.

Tn metallic silver (I) -stabilized complexes stabilized by bridging NHC ligands are disclosed in Catalano et al., Inorganic Chemistry, 2003, 42, 5483-5485. The imidazole units attached to the silver cations via carbene bonds are bridged by means of pyridine heterocycles.

Although compounds, preferably iridium complexes, are known which exhibit electroluminescence in the visible, especially in the red, green and especially blue region of the electromagnetic spectrum, it is desirable to provide alternative compounds which contain less expensive metals and have high quantum yields. In the context of the present invention, electroluminescence is understood as meaning both electrofluorescence and electrophosphorescence.

It is therefore an object of the present invention to provide compounds which are capable of electroluminescence in the visible, in particular blue, red and green, Range of the electromagnetic spectrum, thereby enabling the production of full-color displays and white OLEDs. Furthermore, it is an object of the present invention to provide corresponding complexes which can be used as a mixture with a host compound or in substance, ie in the absence of host substances, as a light-emitting layer in OLEDs. Furthermore, it is an object to provide corresponding complexes which have a high quantum efficiency. The complexes should be usable as emitter, matrix material, charge transport material or charge blocker in OLEDs. These objects are achieved according to the invention by dinuclear carbene complexes of the general formula (I)

(I) wherein A, M, R ¹ , R ² and R ^{3 have} the following meanings

A is independently N or C,

M independently of one another Ag, Au or Cu,

R ¹ independently of one another, linear or branched, optionally interrupted by at least one heteroatom, optionally bearing at least one functional group having 1 to 20 carbon atoms, substituted or unsubstituted, optionally interrupted by at least one heteroatom, optionally bearing at least one functional group cycloalkyl having 3 to 20 carbon atoms, substituted or unsubstituted aryl radical having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl radical having 5 to 30 carbon atoms and / or heteroatoms and

R ² , R ^{3 are} independently of one another free electron pair, if A is N, or, if A is C, independently of one another hydrogen, linear or branched alkyl radical optionally having at least one heteroatom and optionally carrying at least one functional group having 1 to 20 carbon atoms, substituted or unsubstituted, optionally interrupted by at least one heteroatom, optionally bearing at least one functional group cycloalkyl radical having 3 to 20 carbon atoms, substituted or unsubstituted aryl radical having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl radical having 5 to 30 carbon and / or heteroatoms, or

R ¹ and R ² or R ² and R ³ form together with the atoms A and / or N of the N-heterocyclic carbene an optionally interrupted by at least one heteroatom saturated, unsaturated or aromatic carbon ring having a total of 5 to 30 carbon and / or heteroatoms.

The compounds of the general formula (I) may also be present in the following mesomeric limit formula:

(I)

For the purposes of the present invention, the terms aryl radical or group, heteroaryl radical or group and alkyl radical or group have the following meanings: An aryl radical or group is to be understood as meaning a radical having a skeleton of 6 to 30 carbon atoms, preferably 6 to 18 carbon atoms, which is composed of one aromatic ring or several condensed aromatic rings. Suitable backbones are, for example, phenyl, benzyl, naphthyl, anthracenyl or phenanthrenyl. This backbone may be unsubstituted, that is, all carbon atoms that are substitutable bear hydrogen atoms or one or more

or all substitutable positions of the backbone. Suitable substituents are, for example, alkyl radicals, preferably alkyl radicals having 1 to 8 carbon atoms, more preferably methyl, ethyl, i-propyl or t-butyl, aryl radicals, preferably C ₆ -aryl radicals, which in turn may be substituted or unsubstituted, heteroaryl radicals, preferably heteroaryl radicals, which contain at least one nitrogen atom, particularly preferably pyridyl radicals, alkenyl radicals, preferably alkenyl radicals which carry a double bond, particularly preferably alkenyl radicals having a double bond and 1 to 8 carbon atoms, or groups having a donor or acceptor action. Donor-action groups are to be understood as meaning groups having a +1 and / or + M effect, and acceptor-accepting groups are understood as meaning groups having an -I and / or -M effect. Suitable groups with donor or acceptor action are halogen radicals, preferably F, Cl, Br, particularly preferably F, alkoxy radicals, aryloxy radicals, carbonyl radicals, ester radicals, amine radicals, amide radicals, CH ₂ F groups, CHF ₂ groups, CF ₃ groups, CN groups, thio groups or SCN groups. Most preferably, the aryl radicals carry substituents selected from the group consisting of methyl, F, CF ₃ , amine radicals, thio groups and alkoxy, or the aryl radicals are unsubstituted. The aryl radical or the aryl group is preferably a C ₆ -aryl radical which is optionally substituted by at least one of the abovementioned substituents. The C ₆ -aryl radical particularly preferably has no, one, two or three of the abovementioned substituents, where the one substituent is preferably arranged in ortho, meta and / or para position to the further point of attachment of the aryl radical. Most preferably, the C ₆ aryl group in a 2-, 4- and 6-position with Ci _-3 alkyl radicals, preferably methyl radicals substituted phenyl, ie, a mesityl.

A heteroaryl radical or a heteroaryl radical is to be understood as meaning radicals having from 5 to 30 carbon atoms and / or heteroatoms which differ from the abovementioned aryl radicals in that at least one carbon atom in the skeleton of the aryl radicals is replaced by a heteroatom. Preferred heteroatoms are N, O and S. Most preferably, one or two carbon atoms of the backbone of the aryl radicals are replaced by heteroatoms. Most preferably, the backbone is selected from electron-deficient systems such as pyridyl, pyrimidyl, pyrazyl and triazyl, and five-membered ones Heteroaromatics such as pyrrole, furan, thiophene, imidazole, pyrazole, triazole, oxazole and thiazole. The backbone may be substituted at one, several or all substitutable positions of the backbone. Suitable substituents are the same as those already mentioned with respect to the aryl groups.

An alkyl radical or an alkyl group is to be understood as meaning a radical having 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, particularly preferably 1 to 8 carbon atoms. This alkyl radical may be branched or unbranched and may optionally be interrupted by one or more heteroatoms, preferably N, O or S. In addition, this alkyl radical may be substituted by one or more of the substituents mentioned with respect to the aryl groups. It is also possible that the alkyl radical carries one or more aryl groups. All of the aryl groups listed above are suitable. The alkyl radicals are particularly preferably selected from the group consisting of methyl, ethyl, i-propyl, n-propyl, i-butyl, n-butyl, t-butyl, sec-butyl, i-pentyl, n-pentyl, sec-pentyl , neo-pentyl, n-hexyl, i-hexyl and sec-hexyl. Very particular preference is given to methyl, i-propyl, tert-butyl.

A cycloalkyl radical or a cycloalkyl group is to be understood as meaning a cyclic radical having 3 to 20 carbon atoms, preferably 3 to 10 carbon atoms, particularly preferably 3 to 8 carbon atoms. This cycloalkyl radical may optionally be interrupted by one or more heteroatoms, preferably N, O or S. Furthermore, this cycloalkyl radical may be unsubstituted or substituted, ie substituted with one or more of the substituents mentioned with respect to the aryl groups. It is also possible that the cycloalkyl radical carries one or more aryl groups. All of the aryl groups listed above are suitable. The cycloalkyl radicals are particularly preferably selected from the group consisting of cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl. Most preferred is cyclohexyl. According to the invention, the statements made with regard to the aryl, heteroaryl, alkyl and cycloalkyl radicals apply, independently of one another, to the radicals R ¹ , R ² and R ³ , where R ² and R ^3, in the case where A is N, denote a free electron pair , ie, that there is no substituent selected from the above-mentioned group on these ring nitrogen atoms. In the case where A is C, hydrogen and / or the substituents mentioned are independently of one another R ² and R ³ .

In a further embodiment of the dinuclear complexes of the general formula (I), R ¹ and R ² or R ² and R ³ together with the atoms A and / or N of the N-heterocyclic carbene form a saturated, unsaturated or optionally interrupted by at least one heteroatom aromatic carbon ring with 5 to 30 carbon atoms and / or heteroatoms. "Overall" according to the present invention means that the ring atoms A, which in this embodiment are equal to C. According to the invention, only the radicals R ¹ and R ² or R ² and R ^{2 form} R ³ corresponding rings, which are located on the same five-membered ring.

In a preferred embodiment, R ² and R ³ together form an optionally interrupted by at least one heteroatom saturated, unsaturated or aromatic carbon ring having a total of 5 to 30 carbon and / or heteroatoms. For example, R ² and R ³ together with the two ring atoms form a cyclopentenyl, cyclohexenyl, phenyl, pyridine, pyrimidine or pyrazine ring.

In the dinuclear complexes of general formula (I), M is independently Ag, Au or Cu. According to formula (I), two metal atoms M are present in the complexes according to the invention. According to the invention, it is possible for two identical metal atoms, for example two Ag, two Au or two Cu, or two different metal atoms M, for example Ag and Au, Ag and Cu or Au and Cu, to be present in a complex. In a preferred embodiment of the present invention, there are two identical metal atoms in the dinuclear complexes of the general formula (I), more preferably two Ag atoms.

In the dinuclear carbene complexes of the general formula (I) according to the invention, the metal atoms M are present in the oxidation state + 1. In a particularly preferred embodiment of the dinuclear carbene complex according to the invention, A, M, R ¹ , R ² and R ^{3 have} the following meanings:

A C,

M is Ag, independently of one another, linear or branched alkyl radical having 1 to 4 carbon atoms, for example isopropyl or tert-butyl, or substituted or unsubstituted cycloalkyl radical having 3 to 8 carbon atoms, for example cyclohexyl, or substituted or unsubstituted aryl radical having 6 to 10 carbon atoms For example, 2,4,6-trimethylphenyl (mesityl), or substituted or unsubstituted heteroaryl having 5 to 30 carbon atoms and / or heteroatoms and R ² , R ^{3 are} independently hydrogen, linear or branched alkyl radical having 1 to 6 carbon atoms, or substituted or unsubstituted aryl radical having 6 to 10 carbon atoms or substituted or unsubstituted heteroaryl radical having 5 to 30 carbon and / or heteroatoms. or

R ² and R ³ form together with the atoms A an optionally interrupted by at least one heteroatom aromatic carbon ring having a total of 5 to 10 carbon and / or heteroatoms,

In a very particularly preferred embodiment, the dinuclear carbene complexes of the general formula (I) according to the invention correspond to the following formulas (Ia), (Ib), (Ic) or (Id):

(Ib) 

11

The aforementioned dinuclear carbene complexes and mixtures thereof are eminently suitable as emitter molecules in organic light-emitting diodes (OLEDs). Variations of the ligands make it possible to provide corresponding complexes which exhibit electroluminescence in the red, green and especially in the blue region of the electromagnetic spectrum. The neutral transition metal complexes used according to the invention are therefore suitable for use in technically usable OLEDs.

The present invention also relates to a process for the preparation of the dinuclear carbene complexes of the invention by contacting compounds containing the corresponding metal cation with the corresponding ligands or ligand precursors.

Usual procedures are for. B. the deprotonation of, the ligands of the compounds of general formula (I) corresponding ligand precursors and subsequent, generally in situ, reaction with suitable M-containing Metal compounds, in particular Ag, Au and / or Cu-containing metal compounds. This embodiment is preferred.

Furthermore, the preparation of the complexes of the general formula (I) according to the invention can be carried out by direct reaction of the neutral ligand precursors corresponding to the ligands of the corresponding complexes of the general formula (I) with suitable metal-containing compounds.

Another method of preparation is transmetalation, in which the ligand is transferred from one metal to another.

Suitable ligand precursors which lead to the ligands of the carbene complexes of the general formula (I) are known to the person skilled in the art, for example the corresponding imidazolium, benzimidazolium or triazolium salts. Methods for preparing these ligand precursors are known to those skilled in the art.

If a deprotonation of the ligands, so this can be known by those skilled in basic compounds, such as basic metalates, basic metal acetates, acetylacetonates or alkoxylates or bases such as KO'Bu, NaO'Bu, LiO'Bu, NaH, silylamides and phosphazene bases respectively. Preferably, the deprotonation takes place with Ag ₂ 0th

The reaction is preferably carried out in a solvent. Suitable solvents are known per se to those skilled in the art and are preferably selected from the group consisting of aromatic or aliphatic solvents, ethers, alcohols, esters, amides, ketones, nitriles, halogenated compounds and mixtures thereof. A particularly preferred solvent is dichloromethane.

Compounds which are suitable for the process according to the invention and contain the corresponding metal atom (s) M are generally all compounds known to the person skilled in the art which have a sufficiently high reactivity under the reaction conditions according to the invention. Examples of suitable compounds are, for example, silver (I) oxide Ag ₂ O, AgBF ₄ , Ag ₂ CO ₃ , Ag (OOCCH ₃ ), AgNO ₃ , Cu ₂ O, CuI, CuBr, CuCl, Cu (OTf) ₂ , [Cu (CH ₃ CN) ₄ ] PF ₆ , Au (tht) Cl, Au (SMe ₂ ) Cl or mixtures thereof.

The molar ratio of metal-containing compound used to ligand precursor used is generally 1 to 10, preferably 1 to 5, particularly preferably 1 to 1.2. The reaction is generally carried out at a temperature of 0 to 160 ° C, preferably 10 to 100 ° C, particularly preferably 20 to 50 ° C, for example room temperature. The reaction time depends on the desired carbene complex and is generally 0.1 to 50 hours, preferably 0.5 to 40 hours, more preferably 10 to 30 hours, for example 24 hours.

The resulting carbene complex of the general formula (I) is worked up by methods known to the person skilled in the art. For example, the product precipitated during the reaction is filtered, washed, e.g. B. with ether, in particular diethyl ether, and then dried. By recrystallization, z. B. from dichloromethane / diethyl ether or dichloroethane / diethyl ether, highly pure, inventive carbene complexes are obtained.

The dinuclear carbene complexes of the general formula (I) according to the invention are outstandingly suitable as emitter substances, since they have an emission (electroluminescence) in the visible range of the electromagnetic spectrum, for example at 400 to 500 nm. The dinuclear carbene complexes make it possible to provide compounds which have electroluminescence in the red, green and blue regions of the electromagnetic spectrum. Thus, it is possible to provide technically usable OLEDs as emitter substances by means of the dinuclear carbene complexes according to the invention. A particular property of the dinuclear carbene complexes of the general formula (I) according to the invention is that they exhibit luminescence in the solid state, particularly preferably electroluminescence, in the visible region of the electromagnetic spectrum. These luminescent in the solid state complexes can be used in substance, ie without further additives, as emitter substances in OLEDs. As a result, an OLED with a light-emitting layer can be produced, wherein no complex co-evaporation of a matrix material with the emitter substance is required. Dinuclear carbene complexes of the general formula (I) according to the present invention, which exhibit luminescence in the solid, in particular electroluminescence, are not known from the prior art. The complexes are preferably used in a matrix.

A further subject of the present application is therefore an OLED containing at least one dinuclear carbene complex of the general formula (I) according to the invention. Another object of the present application is also the use of the dinuclear carbene complexes of the general formula (I) as a light-emitting layer in OLEDs, preferably as an emitter, matrix material, charge transport material and / or charge blocker.

Organic light-emitting diodes are basically composed of several layers:

Anode (1)

- hole-transporting layer (2)

Light-emitting layer (3)

Electron-transporting layer (4)

Cathode (5) The dinuclear carbene complexes of the general formula (I) are preferably used in the light-emitting layer (3) as emitter molecules.

A further subject of the present application is therefore a light-emitting layer containing at least one of the dinuclear carbene complexes according to the invention of the general formula (I), preferably as emitter molecule. Preferred dinuclear carbene complexes of the general formula (I) have already been mentioned above.

The dinuclear carbene complexes of the general formula (I) used according to the invention can be present in substance, ie without further additives, in the light-emitting layer. However, it is also possible that, in addition to the dinuclear carbene complexes of the general formula (I) used according to the invention, further compounds are present in the light-emitting layer. For example, a fluorescent dye may be present to alter the emission color of the dinuclear carbene complex used as the emitter molecule. Furthermore, a diluent material can be used. This diluent material may be a polymer, e.g. As poly (N-vinylcarbazole) or polysilane. However, the diluent material may also be a small molecule, e.g. 4,4'-N, N'-dicarbazolebiphenyl (CDP) or tertiary aromatic amines. When a diluent material is used, the proportion of the dinuclear carbene complexes used in the light-emitting layer according to the invention is generally less than 40% by weight, preferably from 3 to 30% by weight. The dinuclear carbene complexes of the general formula (I) according to the invention are preferably used in a matrix. Thus, the light-emitting layer preferably contains at least one dinuclear carbene complex of the general formula (I) according to the invention and a matrix material as diluent material.

Another object of the present application is a light-emitting layer containing at least one dinuclear carbene complex of the general formula (I) as an emitter molecule. Preferred complexes of the general formula (I) have already been mentioned above.

The individual of the abovementioned layers of the OLED can in turn be made up of two or more layers. For example, the hole-transporting layer may be constructed of a layer into which holes are injected from the electrode and a layer that transports the holes away from the hole-injecting layer into the light-emitting layer. The electron-transporting layer can also consist of several layers, for. A layer in which electrons are injected through the electrode and a layer which receives electrons from the electron-injecting layer and transports them into the light-emitting layer. These mentioned layers are each selected according to factors such as energy level, temperature resistance and charge carrier mobility as well as energy difference of said layers with the organic layers or the metal electrodes. The person skilled in the art is able to choose the structure of the OLEDs such that it is optimally adapted to the dinuclear carbene complexes according to the invention used as emitter substances according to the present invention. To obtain particularly efficient OLEDs, the HOMO (highest occupied molecular orbital) of the hole-transporting layer should be aligned with the work function of the anode and the LUMO (lowest unoccupied molecular orbital) of the electron-transporting layer should be aligned with the work function of the cathode.

A further subject of the present application is an OLED containing at least one light-emitting layer according to the invention. The further layers in the OLED may be constructed of any material commonly employed in such layers and known to those skilled in the art.

The anode is an electrode that provides positive charge carriers. For example, it may be constructed of materials including a metal, a mixture of various metals, a metal alloy, a metal oxide, or a mixture of various metal oxides. Alternatively, the anode may be a conductive polymer. Suitable metals include the metals of Groups 1 1, 4, 5 and 6 of the Periodic Table of the If the anode is to be transparent, mixed metal oxides of groups 12, 13 and 14 of the Periodic Table of the Elements, for example indium tin oxide (ITO), are generally used. It is also possible that the anode (1) contains an organic material, for example polyaniline, as described, for example, in Nature, Vol. 357, pages 477 to 479 (June 1, 1992). At least either the anode or the cathode should be at least partially transparent in order to be able to decouple the light formed. Suitable hole transport materials for the layer (2) of the OLED according to the invention are disclosed, for example, in Kirk-Othmer Encyclopedia of Chemical Technology, 4th edition, Vol. 18, pages 837 to 860, 1996. Both hole transporting molecules and polymers can be used as hole transport material. Commonly used hole transporting molecules are selected from the group consisting of 4,4'-bis [N- (1-naphthyl) -N-phenyl-amino] biphenyl (α-NPD), N, N'-diphenyl-N, N '- bis (3-methylphenyl) - [1,1'-biphenyl] -4,4'-diamine (TPD), 1,1-bis- [(di-4-tolylamino) phenyl] cyclohexane (TAPC), N, N'-bis (4-methylphenyl) -N, N'-bis (4-ethylphenyl) - [1, 1 '- (3,3'-dimethyl) biphenyl] -4,4'-diamine (ETPD), Tetrakis - (3-methylphenyl) -N, N, N ', N'-2,5-phenylenediamine (PDA), α-phenyl-4-N, N-diphenylaminostyrene (TPS), p- (diethylamino) -benzaldehyde diphenylhydrazone (DEH), triphenylamine (TPA), bis [4- (N, N -diethylamino) -2-methylphenyl) (4-methylphenyl) methane (MPMP), 1-phenyl-3- [p- (diethylamino) styryl ] -5- [p- (diethylamino) phenyl] pyrazoline (PPR or DEASP), 1,2-trans-bis (9H-carbazol-9-yl) cyclobutane (DCZB), N, N, N ', N'- tetrakis (4-methylphenyl) - (1, 1'-biphenyl) -4,4'-diamine (TTB) and porphyrin compounds such as copper phthalocyanines. Usually used hole-transporting polymers are selected from the group consisting of polyvinylcarbazoles, (phenylmethyl) polysilanes and polyanilines. It is also possible to obtain hole transporting polymers by doping hole transporting molecules into polymers such as polystyrene and polycarbonate. Suitable hole-transporting molecules are the molecules already mentioned above.

Suitable electron transporting materials for layer (4) of the OLEDs of the present invention include chelated metals such as tris (8-hydroxyquinolato) aluminum (Alq3) with oxinoid compounds, phenanthroline based compounds such as 2,9-dimethyl, 4,7-diphenyl-1,10 phenanthroline (DDPA) or 4,7-diphenyl-1,10-phenanthroline (DPA) and azole compounds such as 2- (4-biphenylyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole (PBD ) and 3- (4-biphenylyl) -4-phenyl-5- (4-t- butylphenyl) -1,2,4-triazole (TAZ). In this case, the layer (4) can serve both to facilitate the electron transport and as a buffer layer or as a barrier layer in order to avoid quenching of the exciton at the interfaces of the layers of the OLED. Preferably, the layer (4) improves the mobility of the electrons and reduces quenching of the exciton.

The cathode (5) is an electrode which serves to introduce electrons or negative charge carriers. The cathode may be any metal or non-metal that has a lower work function than the anode. Suitable materials for the cathode are selected from the group consisting of Group 1 alkali metals, for example Li, Cs, Group 2 alkaline earth metals, Group 12 metals of the Periodic Table of the Elements comprising the rare earth metals and the lanthanides and actinides. Furthermore, metals such as aluminum, indium, calcium, barium, samarium and magnesium and combinations thereof can be used. Furthermore, lithium-containing organometallic compounds or LiF can be applied between the organic layer and the cathode to reduce the operating voltage.

The OLED according to the present invention may additionally contain further layers which are known to the person skilled in the art. For example, a layer can be applied between the layer (2) and the light-emitting layer (3), which facilitates the transport of the positive charge and / or adapts the band gap of the layers to one another. Alternatively, this further layer can serve as a protective layer. In an analogous manner, additional layers may be present between the light-emitting layer (3) and the layer (4) to facilitate the transport of the negative charge and / or to match the band gap between the layers. Alternatively, this layer can serve as a protective layer.

In a preferred embodiment, in addition to the layers (1) to (5), the OLED according to the invention contains at least one of the further layers mentioned below:

a hole injection layer between the anode (1) and the hole-transporting layer (2);

a block layer for electrons between the hole-transporting layer (2) and the light-emitting layer (3);

a blocking layer for holes between the light-emitting layer (3) and the electron-transporting layer (4); an electron injection layer between the electron-transporting layer (4) and the cathode (5).

The person skilled in the art knows how to select suitable materials (for example based on electrochemical investigations). Suitable materials for the individual layers are known in the art and z. As disclosed in WO 00/70655.

Further, it is possible that some or all of the layers (1), (2), (3), (4) and (5) are surface treated to increase the efficiency of charge carrier transport. The selection of materials for each of said layers is preferably determined by obtaining an OLED having a high efficiency.

The preparation of the OLEDs according to the invention can be carried out by methods known to the person skilled in the art. Generally, the OLED is prepared by sequential vapor deposition of the individual layers onto a suitable substrate. Suitable substrates are, for example, glass or polymer films. For vapor deposition, conventional techniques can be used such as thermal evaporation, chemical vapor deposition and others. In an alternative method, the organic layers may be coated from solutions or dispersions in suitable solvents using coating techniques known to those skilled in the art.

In general, the various layers have the following thicknesses: anode (2) 500 to 5000 Å (Angstrom), preferably 1000 to 2000 Å; Hole-transporting layer (3) 50 to 1000 Å, preferably 200 to 800 Å, light-emitting layer (4) 10 to 1000 Å, preferably 100 to 800 Å, Electron-transporting layer (5) 50 to 1000 Å, preferably 200 to 800 Å, cathode (6) 200 to 10,000 Å, preferably 300 to 5000 Å. The location of the recombination zone of holes and electrons in the OLED according to the invention and thus the emission spectrum of the OLED can be influenced by the relative thickness of each layer. That is, the thickness of the electron transport layer should preferably be selected so that the electron / holes recombination zone is in the light-emitting layer. The ratio of the layer thicknesses of the individual layers in the OLED depends on the materials used. The layer thicknesses of optionally used additional layers are known to the person skilled in the art. The OLEDs according to the invention can be used in all devices in which electroluminescence is useful. Suitable devices are preferably selected from stationary and mobile screens and lighting means. The present invention therefore also relates to a device selected from the group consisting of stationary screens and mobile screens and lighting means, comprising an inventive OLED.

Stationary screens are z. For example, screens of computers, televisions, screens in printers, kitchen appliances, and billboards, lights, and billboards. Mobile screens are e.g. Screens in mobile phones, laptops, vehicles and destination displays on buses and trains.

Furthermore, the dinuclear carbene complexes of the general formula (I) according to the invention can be used in inverse-structure OLEDs. The complexes of the invention in these inverse OLEDs are preferably used in turn in the light-emitting layer, particularly preferably as a light-emitting layer without further additives. The construction of inverse OLEDs and the materials usually used therein are known to the person skilled in the art. Examples

The preparation of imidazoles according to the following literature:

1 . Arduengo, A.J., III; Gentry, F.P., Jr .; Taverkere, P.K .; Simmons, H.E., III, 98-1937006177575, 2001

2. Liu, J .; Chen, J .; Zhao, J .; Zhao, Y .; Li, L; Zhang, H., Synt esis 2003, 17, 2661-2666.

Example 1 Synthesis of Bisimidazolium Salts (3a-g)

2 Cl

(2a) R ¹ = mesityl (3a) R ¹ = mesityl, 45%

(SHDT) (2b) R = cyclohexyl (3b) R ¹ = cyclohexyl, 70%

(2c) R = tert-butyl (3c) R = tert-butyl, 65%

(2a) R ¹ = mesityl (3a) R ¹ = mesityl, 43%

(1) (2b) R = cyclohexyl (3b) R = cyclohexyl, 33%

(2c) R = tert -butyl (3c) R ¹ = tert -butyl, 82% (2d) R = isopropyl (3d) R ¹ = isopropyl, 93%

Upper Reaction Scheme, Variant 1: Sodium hydroxy-2,4-dichloro-1,3,5-triazine (SHDT), aqueous solution as reactant, lower reaction scheme, Variant 2:

Cyanuric acid chloride (1) as a reactant.

Variant:

To a stirred solution of the sodium salt of hydroxy-2,4-dichloro-1,3,5-triazine (sodium hydroxy-2,4-dichloro-1,3,5-triazine = SHDT, 8% aqueous solution) in THF (0.8 mL / mmol SHDT) is added a solution of two equivalents of the corresponding imidazole (2a-c) in THF (0.8 mL / mmol imidazole). The monophasic solution is refluxed for up to 5 days. The solid formed in some cases is filtered off and the filtrate is concentrated in vacuo. The crude product is dissolved in a small amount of CH ₂ Cl ₂ and precipitated by the addition of diethyl ether. The solid is filtered off, washed with acetone if necessary and dried in vacuo.

Variant 2:

To a solution of cyanuric chloride (1) in acetonitrile (5 mL / mmol cyanuric chloride) is added dropwise up to 5 equivalents of the corresponding imidazole (2a-d) in acetonitrile (about 10 mL / mL imidazole) at 0 ° C, whereupon forms a solid. The suspension is stirred for 30 minutes at room temperature, 30 minutes at 60 ° C and then refluxed for 4.5 hours. The resulting solid is filtered off, washed with (hot) aceonitrile and dried in vacuo. Analytical data:

1.1 4,6-bis- (1-mesitylimidazolium-3-yl) -1, 3,5-triazine-2-olate chloride hydrochloride

(3a)

Variant 1: Yield 45%

¹ H-NMR (DMSO-de): δ (ppm) 10.52 (s, 2H, N-CH = N), 8.83 (s, 2H, N-CH = CH), 8.18 (s, 2H, N-CH = CH), 7.18 (s, 4H, CH _ar), 2:34 (s, 6H, CH ₃ ^para), 2.10 (s, 12H, CH ₃ ^ortho).

1.2 4,6-Bis (1-cyclohexylimidazolium-3-yl) -1, 3,5-triazine-2-olate chloride hydrochloride (3b)

Variant 1: Yield 70%

¹ H-NMR (DMSO-de): δ (ppm) 10.42 (s, 2H, N-CH = N), 8.58 (s, 2H, N-CH = CH), 8.15 (s, 2H, N-CH = CH), 4:44 (m, 2H, c ^ '^ ^0'), 2.10 (m, 4H, CH ₂ ^cyclohexyl), 1 .90 (m, 8H, CH ₂ ^cyclohexyl), 1 .70 (m, 2H, CH ₂ ^cyclohexyl ), 1 .30 (m, 6H, CH ₂ ^cyclohexyl ).

1.3 4,6-bis (1 -feri-butylimidazolium-3-yl) -1, 3,5-triazine-2-olate chloride (3c)

Variant 2: Yield 82%

¹ H-NMR (DMSO-de): δ (ppm) 10.21 (s, 2H, N-CH = N), 8.70 (s, 2H, N-CH = CH), 8.26 (s, 2H, N-CH = CH), 1 .70 (s, 9H, CH _3).

1.4 4,6-bis (1-isopropylimidazolium-3-yl) -1, 3,5-triazine-2-olate chloride

Hydrochloride (3d)

Variant 2: Yield 93%

¹ H-NMR (DMSO-de): δ (ppm) 10.52 (s, 2H, N-CH = N), 8.61 (s, 2H, N-CH = CH), 8.18 (s, 2H, N-CH = CH), 4.82 (sept, J = 6.7 Hz, 1 H, CH), 1.60 (s, 6H, _CH3), 1:58 (s, 6H, CH _3).

1.5 4,6-bis- (1-cyclopentylimidazolium-3-yl) -1, 3,5-triazine-2-olate chloride

hydrochloride (3e

(3e)

The product is obtained analogously to the general method of synthesis (variant 2) as a white solid. (598 mg, 14%). ¹ HN MR (DMSO-de): δ (ppm) 10.26 (s, 2H, N-CH = N), 8.57 (s, 2H, N-CH = CH), 8.08 (s, 2H, N-CH = CH ), 4.89 (sept, 2H, CH), 1.40-2.30 (m, 16H, CH ₂ ). ¹³ CN MR (DMSO-d ₆ ): δ (ppm) 165.20 {C _ipso ), 159.68 (C _ip so), 135.28 (CH), 121.86 (CH), 1 19.28 (CH), 61.29 (CH ), 32.41 (CH ₂ ), 23.27 (CH ₂ ).

4,6-Bis (1-p-methylphenylimidazolium-3-yl) -1, 3,5-triazine-2-olate chloride hydrochloride (3f)

(3f)

The product is obtained analogously to the general method of synthesis (variant 2) and recrystallization from ethanol as a pale yellow solid. (648 mg, 25%).

1 H NMR (DMSO-de): δ (ppm) 10.80 (s, 2H, N-CH = N), 8.82 (s, 2H, N-CH = CH), 8.53 (s, 2H, N-CH = CH ), 7.90 (s, 2H, CH _aromatic ), 7.87 (s, 2H, CH _aromatic ), 7.51 (s, 2H, CH _aromatic ), 7.48 (s, 2H, CH _aromatic ), 2.43 (s, 6H, CH ₃ ^para ). ¹³ CN MR (DMSO-d ₆ ): δ (ppm) 159.71 (Cip _S0 ), 140.20 (Cip _S0 ), 134.75 (CH), 132.16 ( _pso ), 130.29 (CH), 122.45 (CH), 122.27 (CH). , 1 19:55 (CH), 20:56 (CH _3).

1.7 4,6-Bis (1-p-methoxyphenylimidazolium-3-yl) -1,3,5-triazine-2-olate chloride hydrochloride (3g)

(3g)

The product is obtained analogously to the general method of synthesis (variant 2) and recrystallization from an ethanol-acetone-water mixture (3: 1: 0.01) as a pale yellow solid. (2.998g, 62%).

¹ H NMR (DMSO-de): δ (ppm) 10.74 (s, 2H, N-CH = N), 8.79 (s, 2H, N-CH = CH), 8.48 (s, 2H, N-CH = CH ), 7.93 (s, 2H, CH _aromalic ), 7.90 (s, 2H, CH _aromalic ), 7.24 (s, 2H, CH _aramaic ), 7.21 (s, 2H, CH _arama tic), 3.87 (s, 6H, OCH ₃ ^para ). ¹³ C NMR (DMSO-d ₆ ): δ (ppm) 165.23 (Qpso), 160.29 (Qpso), 159.72 (C _ip so), 134.73 (CH), 127.52 (C _ip so), 124.04 (CH), 122.63 ( CH), 1 19:38 (CH), 1 14.89 (CH), 55.72 _(CH3). Example 2: Synthesis of Silver-NHC Complexes (5)

(3a) R ¹ = mesityl (5a) R ¹ = mesityl, 75%

(3b) R = cyclohexyl (5b) R ¹ = cyclohexyl, 77%

(3c) R = tert-butyl (5c) R = tert-butyl, 40%

(3d) R = isopropyl (5d) R ¹ = isopropyl, 55%

Di- [silver (I) -4,6-bis (1-mesitylimidazoN

(5a)

In a 25 mL round bottom flask protected from light, 269 mg of bisimidazolium salt (3a) and 142 mg of silver (I) oxide are suspended in 15 mL of dichloromethane. After 24 hours of stirring at room temperature, the suspension is filtered through Celite ^® and concentrated to a volume of about 5 mL. The crude product is precipitated by the addition of 20 mL diethyl ether, then washed twice with yes 10 mL diethyl ether and dried in vacuo, from which the product is isolated in 64% yield as a colorless solid (182.7 mg). ¹ H-NMR (DMSO-d ₆ ): δ (ppm) 8.26 (s, 4H, N-CH = CH), 6.83 (s, 4H, N-CH = CH), 6.80 (s, 4H, CH _ar ) , 6.75 (s, 4H, CH _ar ), 2.26 (s, 12H, CH ₃ ^para ), 1 .75 (s, 4H, H ₂ 0), 1 .60 (s, 12H, CH ₃ ^ortho ), 1. 54 (s, 12H, CH ₃ ^ortho).

2.2 di- [silver (1) -4,6-bis (1 -cyc / oftexylimidazoline-2,2'-diylidene-3-yl) -1,3,5-triazine-2-olate (5b)

In a 25 mL round bottom flask protected from light, 232.6 mg of bisimidazolium salt (3b) and 142 mg of silver (I) oxide are suspended in 15 mL of dichloromethane. After 24 hours of stirring at room temperature, the suspension is filtered through Celite ^® and concentrated to a volume of about 5 mL. The crude product is precipitated by the addition of 20 mL diethyl ether, then washed twice with yes 10 mL diethyl ether and dried in vacuo, from which the product is isolated in 70% yield as a colorless solid (174 mg). ¹ H-NMR (DMSO-d ₆ ): δ (ppm) 8.09 (s, 4H, N-CH = CH), 6.96 (s, 4H, N-CH = CH), 3.83 (m, 4H, CH), 1 .75 (s, 8H, H ₂ O), 0.80-1 .75 (m, 40H, CH ₃ ). 2.3 di- [silver (1) -4,6-bis (1 -ferf-butylimidazoline-2,2'-diylidene-3-yl) -1,3,5-triazine-2-olate (5c)

In a 25 mL round bottom flask protected from light, 206 mg of bisimidazolium salt (3c) and 142 mg of silver (I) oxide are suspended in 15 mL of dichloromethane. After 24 hours of stirring at room temperature, the suspension is filtered through Celite ^® and concentrated to a volume of about 5 mL. The crude product is precipitated by the addition of 20 mL diethyl ether, then washed twice with yes 10 mL diethyl ether and dried in vacuo, from which the product is isolated in 40% yield as a colorless solid (90.5 mg). ¹ HN MR (DMSO-d ₆ ): δ (ppm) 8.10 (s, 4H, N-CH = CH), 7.14 (s, 4H, N-CH = CH), 1.67 (s, 13.2H, H ₂ 0), 1 .37 (d, 34H, CH ₃ ).

2.4 di- [silver (1) -4,6-bis (1-isopropylimidazoline-2,2'-diylidene-3-yl) -1,3,5-triazine-2-olate (5d)

In a 25 mL round bottom flask protected from light, 193 mg of bisimidazolium salt (3b) and 142 mg of silver (I) oxide are suspended in 15 mL of dichloromethane. After 24 hours of stirring at room temperature, the suspension is filtered through Celite ^® and concentrated to a volume of about 5 mL. The crude product is precipitated by the addition of 20 mL diethyl ether, then washed twice with yes 10 mL diethyl ether and dried in vacuo, from which the product is isolated in 55% yield as a colorless solid (1 15.1 mg). ¹ H-NMR (DMSO-d ₆ ): δ (ppm) 8.10 (s, 4H, N-CH = CH), 6.97 (s, 4H, N-CH = CH), 4.30 (sept, 4H, CH), 1 .30 (d, 12H, CH _3), 0.97 (d, 12H, CH _3).

2.5 di- [silver (I) -4,6-bis (1-cyclopentylimidazoline-2,2'-diylidene-3-yl) -1,3,5-triazine-2-olate] (5e)

(5e) In a light-protected 25 mL single-necked flask, 44 mg of bisimidazolium salt (3e) and 28 mg of silver (I) oxide are suspended in 10 ml of dichloromethane. After stirring for 24 h at room temperature, the suspension is filtered through Celite and then concentrated in vacuo to about 3 mL. By addition of 20 mL diethyl ether, the crude product is precipitated, filtered and washed twice with 10 mL diethyl ether. After drying in vacuo, the product is obtained as a white solid in 30% yield (29 mg).

¹ HN MR (DMSO-de): δ (ppm) 8.12 (s, 4H, N-CH = CH), 6.97 (s, 4H, N-CH = CH), 4.41 (sept, 4H, N-CH-CH ₂ ), 2.1 (acetonitrile), 2.0-1.2 (m, 32, CH ₂ ). ¹³ C NMR (DMSO-d ₆ ): δ (ppm) 183.90 (dd, C _carbene ), 168.84 (C _ipso ), 162.68 (C _ipso ), 1 19.26 (CH), 63.52 (CH), 34.47 (CH ₂ ), 32.93 (CH ₂ ), 24.41 (CH ₂ ), 24.36 (CH ₂ ).

2.6 di- [silver (1) -4,6-bis (1-p-methylphenylimidazoline-2,2'-diylidene-3-yl) -1, 3,5-triazin-2-olate] (5f)

(5f)

In a 250 ml light-protected flask, 241 mg of bisimidazolium salt (3f) and 139 mg of silver (I) oxide are suspended in 100 ml of dichloromethane. After stirring for 24 h at room temperature, the suspension is filtered through Celite and then concentrated in vacuo to about 10 mL. By addition of 100 ml of diethyl ether, the crude product is precipitated, filtered and washed twice with 20 ml of diethyl ether. After drying in vacuo, the product is obtained as a white solid in 24% yield (123 mg).

1 H NMR (DMSO-de): δ (ppm) 8.37 (s, 4H, N-CH = CH), 7.24 (s, 4H, N-CH = CH), 7.04 (s, 4H, C / - _aroma tic ), 7:01 (s, 4H, CH _{aromat \ c),} 6.98 (s, 4H, CH _{aromat \ c),} 6.95 (s, 4H, CH _{aromat \ c),} (2.30 s, 12H, CH ₃ ^para), 1 .75 (H ₂ 0). ¹³ C NMR (DMSO-d ₆ ): δ (ppm) 184.36 (dd, C _carbe ne), 181, 62 (dd, C _carbene ), 168.64 (C _ipso ), 162.58 ( _pso ), 139.60 ( _pso ), 137.27 ( _pso ), 130.12 (CH), 122.49 (CH), 121.78 (d, CH) , 1 19.80 (d, CH), 20.96 _(CH3).

2.7 di- [silver (l) -4,6-bis (1-p-methoxyphenylimidazoline-2,2'-diylidene-3-yl) -1, 3,5-triazin-2-olate] (5g)

(5g)

In a 250 ml light-protected flask, 514 mg of bisimidazolium salt (3 g) and 278 mg of silver (I) oxide are suspended in 200 ml of dichloromethane. After 48 h stirring at room temperature, the suspension is filtered through Celite and then concentrated in vacuo to about 10 mL. By addition of 100 mL diethyl ether, the crude product is precipitated, filtered and washed twice with 10 mL diethyl ether. After drying in vacuo, the product is obtained as a white solid in 3% yield (31 mg).

¹ H NMR (DMSO-de): δ (ppm) 8.34 (d, 4H, N-CH = CH), 7.23 (d, 4H, N-CH = CH), 6.99 (s,

4H, C / - / _aromat ic), 6.96 (S, 4H, CH _ara matic). 6.74 (S, 4H, C / - / _aromat ic), 6.71 (S, 4H, C - / _ara matic) _>

3.78 (s, 12H, CH ₃ ^para ), 1 .59 (H ₂ 0). ¹³ C NMR (DMSO-d ₆ ): δ (ppm) 168.57 (C _ipso ), 162.66 (Cip _S0 ), 160.06 (Cip _S0 ), 132.68 ( _pso ), 124.08 (CH), 122.01 (d, CH), 1 19.67 (d, CH), 1 14.60 (CH), 55.77 _(CH3). ESI / MS (m / z): 1095.1 [M + H] ⁺ .

Example 3: Photoluminescence (PL) Data Example 3.1

(5d)

Example 3.2

Example 3.3

Example 3.4

(5a)

The graph of the photoluminescence measurement is shown in FIG. The measurement is carried out with a thin layer consisting of 2% complex in PMMA. The wavelength is in nm on the x-axis, and the counts are plotted on the y-axis.

Example 4: Synthesis of Gold NHC Complexes (6) 4.1 Di- [gold (1) -4,6-bis (1 -ferf-butyl-imidazoline-2,2'-diylidene-3-yl) -1 , 3,5-triazine-2-olate] (6a)

(6a)

100 mg of di- [silver (I) -4,6-bis- (1-iert-butyl-imidazoline-2,2'-diylidene-3-yl) -1,3,5-, in a light-protected 50 mL round bottom flask. Triazine-2-olate (5c) and 72 mg of gold (l) - tetrahydro-thiophene-chloride stirred at room temperature for 3 hours in acetonitrile. The resulting suspension is filtered through Celite and then concentrated in vacuo. By addition of 30 mL diethyl ether, the crude product is precipitated, filtered and washed twice with 10 mL diethyl ether. After drying in vacuo, the product is obtained as a white solid in 50% yield (60 mg).

1H NMR (CDCl ₃ ): δ (ppm) 8.05 (d, 4H, N-CH = CH), 7.12 (d, 4H, N-CH = CH), 1.67 (H ₂ O), 1 .50 (s, 36H, CH _3). ¹³ C NMR (CDCl ₃ ): δ (ppm) 181.79 ( _carbenee ), 168.87 (C _ipso ), 162.62 (Cip _so ), 1 18.56 (CH), 1 17.66 (CH), 58.94 (CH), 30.47 ( CH ₃ ).

ESI / MS (m / z): 1075.3 [M + H] ⁺ .

Example 5 Synthesis of Copper NHC Complexes (7)

Di- [copper (1) -4,6-bis (1-mesitylimidazoline-2,2'-diylidene-3-yl) -1, 3,5-triazine-2-olate] (7a)

(7a)

The reaction is carried out in a glove box under argon atmosphere. To 400 mg of the bisimidazolium salt (3a), 75 mg of copper (I) oxide and 183 mg of sodium acetate are added 20 mL of dry acetonitrile and the reaction mixture is refluxed for 3 hours, whereupon a yellow coloration occurs. The reaction mixture is filtered through Celite and then evaporated, whereupon a yellow-orange solid forms.

¹ HN MR (CDCIs): δ (ppm) 8.10 (s, 4H, N-CH = CH), 6.78 (s, 4H, N-CH = CH), 6.75 (s, 8H, CH _arom ), 2.26 (i.e. , 12H, CH _{3, para),} 1 .61 (d, 12H, CH _3), 1 .55 (d, 12H, CH _3).

5.2 di [copper (l) -4,6-bis- (1 - / ^{'so-propyl-imidazoline-2,2'-diylidene-3-yl)} -1, 3,5-triazin-2-olate] (7b)

To 500 mg of the bisimidazolium salt (3d), 130 mg of copper (I) oxide and 320 mg of sodium acetate are added 25 mL of DMSO in a heated Schlenk flask and the mixture is heated to 90 ° C and stirred for 3 hours, whereupon the solution yellowish greenish discolored. The reaction mixture is then concentrated in vacuo to about 5 mL, 10 mL of dry methanol are added, whereupon the solution turns green. The crude product is then precipitated with 50 ml of dry diethyl ether and washed again with small volumes of diethyl ether. The product is obtained as a yellowish-green solid (124 mg, 18%).

¹ H NMR (DMSO-de): δ (ppm) 7.89 (s, 4H, N-CH = CH), 7.54 (s, 4H, N-CH = CH), 4.18 (sept, 4H, N-CH-CH _2), 1 .13 (d, 12H, CH _3), 1:01 (d, 12H, CH _3).

Claims

claims

Dinuclear carbene complexes of the general formula (I)

(I) wherein A, M, R ¹ , R ² and R ^{3 have} the following meanings:

A is independently N or C,

M independently of one another Ag, Au or Cu,

R ^{1 is} independently linear or branched, optionally interrupted by at least one heteroatom, optionally carrying at least one functional group alkyl radical having 1 to 20 carbon atoms, substituted or unsubstituted, optionally interrupted by at least one heteroatom, optionally bearing at least one functional group cycloalkyl having 3 to 20 Carbon atoms, substituted or unsubstituted aryl radical having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl radical having 5 to 30 carbon and / or heteroatoms, and

R ² , R ^{3 are} independently of one another free electron pair, if A is N, or if A is C, independently of one another hydrogen, linear or branched, optionally of at least one heteroatom interrupted, optionally bearing at least one functional group alkyl radical having 1 to 20 Carbon atoms, substituted or unsubstituted, optionally substituted by at least one heteroatom breaker, optionally at least one functional group-carrying cycloalkyl radical having 3 to 20 carbon atoms, substituted or unsubstituted aryl radical having 6 to 30 carbon atoms, substituted or unsubstituted heteroaryl radical having 5 to 30 carbon and / or heteroatoms, or

R ¹ and R ² or R ² and R ³ form together with the atoms A and / or N of the N-heterocyclic carbene an optionally interrupted by at least one further heteroatom saturated, unsaturated or aromatic carbon ring having a total of 5 to 30 carbon and / or heteroatoms.

2. Dinuclear carbene complex according to claim 1, characterized in that A, M, R ¹ , R ² and R ^{3 have} the following meanings:

A C,

M Ag, independently of one another, are hydrogen, linear or branched alkyl radical having 1 to 4 carbon atoms or substituted or unsubstituted cycloalkyl radical having 3 to 8 carbon atoms or substituted or unsubstituted aryl radical having 6 to 10 carbon atoms, substituted or unsubstituted heteroaryl radical having a total of 5 to 30 carbon atoms and / or heteroatoms and independently of one another hydrogen, linear or branched alkyl radical having 1 to 6 carbon atoms, or substituted or unsubstituted aryl radical having 6 to 10 carbon atoms or substituted or unsubstituted heteroaryl radical having in total 5 to 30 carbon atoms and / or heteroatoms or

R ² and R ³ together with the atoms A form an optionally interrupted by at least one heteroatom aromatic carbon ring having a total of 5 to 10 carbon and / or heteroatoms.

 

(Id)

A process for preparing a dinuclear carbene complex according to any one of claims 1 to 3 by contacting compounds containing the corresponding metal cation with the corresponding ligands or ligand precursors. OLED containing at least one dinuclear carbene complex according to one of claims 1 to 3.

Light-emitting layer containing at least one dinuclear carbene complex according to one of claims 1 to 3.

OLED containing at least one light-emitting layer according to claim 6.

Device selected from the group consisting of stationary screens and mobile screens and lighting means, comprising an OLED according to claim 5 or 7.

Use of a dinuclear carbene complex according to one of claims 1 to 3 in OLEDs.

10. Use according to claim 9, characterized in that the dinuclear carbene complexes are used as emitter, matrix material, charge transport material and / or charge blocker.