METAL COMPLEXES

Abstract

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

Claims

1.-15. (canceled)

16. A compound of formula (1)
M(L).sub.n(L′).sub.m  Formula (1) containing a substructure M(L).sub.n of the formula (2): ##STR00504## where the symbols and indices used are as follows: M is iridium or platinum; D is C or N, where one D is C and the other D is N; X is the same or different at each instance and is CR or N; R is the same or different at each instance and is H, D, F, Cl, Br, I, N(R.sup.1).sub.2, CN, NO.sub.2, OR.sup.1, SR.sup.1, COOR.sup.1, C(═O)N(R.sup.1).sub.2, Si(R.sup.1).sub.3, B(OR.sup.1).sub.2, C(═O)R.sup.1, P(═O)(R.sup.1).sub.2, S(═O)R.sup.1, S(═O).sub.2R.sup.1, OSO.sub.2R.sup.1, a straight-chain alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group may in each case be substituted by one or more R.sup.1 radicals, where one or more nonadjacent CH.sub.2 groups may be replaced by Si(R.sup.1).sub.2, C═O, NR.sup.1, O, S or CONR.sup.1, or an aromatic or heteroaromatic ring system which has 5 to 60 aromatic ring atoms, preferably 5 to 40 aromatic ring atoms, and may be substituted in each case by one or more R.sup.1 radicals; at the same time, two R radicals together may also form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system; R.sup.1 is the same or different at each instance and is H, D, F, Cl, Br, I, N(R.sup.2).sub.2, CN, NO.sub.2, OR.sup.2, SR.sup.2, Si(R.sup.2).sub.3, B(OR.sup.2).sub.2, C(═O)R.sup.2, P(═O)(R.sup.2).sub.2, S(═O)R.sup.2, S(═O).sub.2R.sup.2, OSO.sub.2R.sup.2, a straight-chain alkyl group having 1 to 20 carbon atoms or an alkenyl or alkynyl group having 2 to 20 carbon atoms or a branched or cyclic alkyl group having 3 to 20 carbon atoms, where the alkyl, alkenyl or alkynyl group may each be substituted by one or more R.sup.2 radicals, where one or more nonadjacent CH.sub.2 groups may be replaced by Si(R.sup.2).sub.2, C═O, NR.sup.2, O, S or CONR.sup.2 and where one or more hydrogen atoms in the alkyl, alkenyl or alkynyl group may be replaced by D, F, Cl, Br, I or CN, or an aromatic or heteroaromatic ring system which has 5 to 40 aromatic ring atoms and may be substituted in each case by one or more R.sup.2 radicals; at the same time, two or more R.sup.1 radicals together may form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system; R.sup.2 is the same or different at each instance and is H, D, F, CN or an aliphatic, aromatic or heteroaromatic organic radical, especially a hydrocarbyl radical, having 1 to 20 carbon atoms, in which one or more hydrogen atoms may also be replaced by F; L′ is the same or different at each instance and is a ligand; n is 1, 2 or 3; m is 0, 1, 2, 3 or 4; at the same time, it is also possible for two or more ligands L to be joined together or for L to be joined to L′ by a single bond or a bivalent or trivalent bridge, thus forming a tridentate, tetradentate, pentadentate or hexadentate ligand system.

17. The compound as claimed in claim 16, wherein the unit of the formula (2) is selected from the structures of the formula (3) ##STR00505## where the symbols and indices used have the same definitions as described in claim 16.

18. The compound as claimed in claim 16, wherein the unit of the formula (2) is selected from the structures of the formulae (3a) to (3f) and (4a) to (4f), ##STR00506## where the symbols and indices used have the definitions given in claim 16.

19. The compound as claimed in claim 16, wherein the unit of the formula (2) is selected from the structures of the formulae (3a-1) to (4f-1): ##STR00507## where the symbols and indices used have the definitions given in claim 16, and R′ has the same definitions as R, where at least one substituent R′ is not H or D.

20. The compound as claimed in claim 16, wherein the unit of the formula (2) is selected from the structures of the formulae (3a-2) to (4a-6): ##STR00508## where the symbols and indices used have the definitions given in claim 16.

21. The compound as claimed in claim 16, wherein R is the same or different at each instance and is selected from the group consisting of H, D, F, Br, I, N(R.sup.1).sub.2, CN, Si(R.sup.1).sub.3, B(OR.sup.1).sub.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, each of which may be substituted by one or more R.sup.1 radicals, where one or more hydrogen atoms may be replaced by D or F, or an aromatic or heteroaromatic ring system which has 5 to 24 aromatic ring atoms and may be substituted in each case by one or more R.sup.1 radicals; at the same time, two preferably adjacent R radicals together may also form an aliphatic, heteroaliphatic, aromatic or heteroaromatic ring system.

22. The compound as claimed in claim 16, wherein the compound is selected from the structures of the formulae (12) to (15): ##STR00509## where the symbols and indices used have the definitions given in claim 16.

23. The compound as claimed in claim 22, wherein V in the compounds of the formulae (12) and (13) is a group of the formula (26), where the dotted bonds represent the position of the linkage of the sub-ligands L and L′: ##STR00510## where: X.sup.1 is the same or different at each instance and is CR or N; X.sup.2 is the same or different at each instance and is CR or N; A is the same or different at each instance and is CR.sub.2—CR.sub.2, CR.sub.2—O, CR.sub.2—NR, C(═O)—O, C(═O)—NR or a group of the following formula (27): ##STR00511## where the dotted bond in each case represents the position of the bond of the bidentate sub-ligands L or L′ to this structure, * represents the position of the linkage of the unit of the formula (27) to the central trivalent aryl or heteroaryl group.

24. The compound as claimed in claim 22, wherein V in the compounds of the formulae (12) and (13) represents a structure of one of the formulae (36) to (39): ##STR00512## where the symbols used have the definitions given in claim 16.

25. The compound as claimed in claim 16, wherein L′ is the same or different at each instance and is a bidentate monoanionic ligand.

26. A process for preparing the compound as claimed in claim 16 which comprises reacting the free ligands L and optionally L′ with metal alkoxides of the formula (79), with metal ketoketonates of the formula (80), with metal halides of the formula (81), with dimeric metal complexes of the formula (82) or with metal complexes of the formula (83): ##STR00513## where the symbols M, m, n and R have the definitions given in claim 16, Hal=F, Cl, Br or I, L″ is an alcohol or a nitrile and (Anion) is a non-coordinating anion.

27. A formulation comprising at least one compound as claimed in claim 16 and at least one further compound and/or at least one solvent.

28. An electronic device comprising at least one compound as claimed in claim 16.

29. An organic electroluminescent device which comprises the compound as claimed in claim 16 is used as an emitting compound in one or more emitting layers in combination with one or more matrix materials.

Description

EXAMPLES

[0141] The syntheses which follow, unless stated otherwise, are conducted under a protective gas atmosphere in dried solvents. The metal complexes are additionally handled with exclusion of light or under yellow light. The solvents and reagents can be purchased, for example, from Sigma-ALDRICH or ABCR. The respective figures in square brackets or the numbers quoted for individual compounds relate to the CAS numbers of the compounds known from the literature. In the case of compounds that can have multiple enantiomeric, diastereomeric or tautomeric forms, one form is shown in a representative manner.

A: Synthesis of the Synthons S

Example S1

[0142] ##STR00401##

[0143] To a mixture of 29.8 g (100 mmol) of 11-bromobenz[c]imidazo[1,2-a][1,5]naphthyridine [2253277-62-9], 26.7 g (105 mmol) of bis(pinacolato)diborane, 29.4 g (300 mmol) of potassium acetate (anhydrous), 50 g of glass beads (diameter 3 mm) and 500 ml of THE are added, with good stirring, 821 mg (2 mmol) of SPhos and then 225 mg (1 mmol) of palladium(II) acetate, and the mixture is heated under reflux for 16 h. While the mixture is still warm, the salts and glass beads are removed by suction filtration through a Celite bed in the form of a THE slurry, which is washed through with THF, and the filtrate is concentrated to dryness. The residue is taken up in 100 ml of MeOH and stirred in the warm solvent, and the crystallized product is filtered off with suction, washed twice with 30 ml each time of methanol and dried under reduced pressure. Yield: 30.0 g (81 mmol), 81%; purity: about 95% by .sup.1H-NMR.

[0144] The following compounds can be prepared analogously:

TABLE-US-00004 Ex. Reactant Product Yield S2 [00402] [00403] 83% S3 [00404] [00405] 78% S4 [00406] [00407] 63%

Example S50

[0145] ##STR00408##

[0146] To a mixture of 34.5 g (100 mmol) of S1, 28.3 g (100 mmol) of 1-bromo-2-iodobenzene [583-55-1], 31.8 g (300 mmol) of sodium carbonate, 300 ml of toluene, 100 ml of ethanol and 300 ml of water are added, with very good stirring, 788 mg (3 mmol) of triphenylphosphine and then 225 mg (1 mmol) of palladium(II) acetate, and the mixture is heated under reflux for 48 h. After cooling, the organic phase is removed and washed once with 300 ml of water and once with 300 ml of saturated sodium chloride solution, and dried over magnesium sulfate. The desiccant is filtered off and the filtrate is concentrated fully under reduced pressure. The residue is subjected to flash chromatography (Torrent automatic column system from A. Semrau) or recrystallized from acetonitrile/ethyl acetate. Yield: 31.8 g (85 mmol), 85%; purity: about 95% by .sup.1H-NMR.

[0147] The following compounds can be prepared analogously:

TABLE-US-00005 Ex. Reactant Product Yield S51 S2 [00409] 84% S52 S3 [00410] 88% S53 S4 [00411] 86%

B Synthesis of the Ligands L

1) Synthesis of the Tetradentate Ligands TL

Example TL1

[0148] ##STR00412##

[0149] To a suspension, cooled to −78° C., of 15.2 g (50 mmol) of 6-chlorobenzimidazo[2,1-f]benzo[h][1,6]naphthyridine [1228276-32-0] in 200 ml of THE is added dropwise 59.0 ml (100 mmol) of tert-butyllithium (1.7 M in n-pentane), and the mixture is stirred for a further 2 h. Then a solution, precooled to −78° C., of 10.8 g (60 mmol) of 3-(2-pyridyl)benzonitrile [4350-51-0] is added dropwise, and the mixture is stirred at −78° C. for a further 1 h and then allowed to warm up gradually to room temperature. The reaction mixture is quenched by adding 20 ml of methanol, then 100 ml of 5 N hydrochloric acid is added and the mixture is heated under reflux for 2 h. The mixture is adjusted to pH˜9 by adding 5 N aqueous NaOH and extracted three times with 200 ml each time of dichloromethane. The combined organic phases are washed three times with 300 ml each time of water and once with 300 ml of saturated sodium chloride solution and dried over magnesium sulfate. The desiccant is filtered off with suction and washed through thoroughly with dichloromethane, and the filtrate is concentrated to dryness. The crude product is chromatographed on silica gel with dichloromethane/ethyl acetate (8:2 w). Yield: 7.7 g (17 mmol) 34%; purity: about 95% by .sup.1H-NMR.

[0150] B)

[0151] To a solution, cooled to −78° C., of 7.0 g (30 mmol) of 2-bromobiphenyl [2052-07-5] in 100 ml of THE is added dropwise 12.0 ml (30 mmol) of n-butyllithium (2.5 N in hexane), and the mixture is stirred for a further 30 min. Then a solution of 13.5 g (30 mmol) of TL1 Stage A) in 200 ml of THE is added dropwise, and the mixture is allowed to warm up slowly to room temperature and stirred for a further 6 h. The reaction mixture is quenched by adding 10 ml of ethanol, the solvent is evaporated off completely under reduced pressure, the residue is taken up in 200 ml of glacial acetic acid, 1 ml of conc. sulfuric acid is added dropwise while stirring, and the mixture is stirred at 60° C. for a further 3 h. Then the glacial acetic acid is largely removed under reduced pressure, the residue is taken up in 300 ml of dichloromethane, and the mixture is alkalized by adding 5% by weight aqueous NaOH while cooling with ice. The organic phase is separated off, washed three times with 200 ml each time of water and dried over magnesium sulfate, the organic phase is concentrated completely, and the residue is taken up in 300 ml of methanol, homogenized while heating and then stirred for a further 12 h, in the course of which the product crystallizes. The crude product is filtered off with suction, washed twice with 30 ml each time of methanol, dried under reduced pressure and recrystallized twice from toluene:isopropanol (5:1). Yield: 6.5 g (11 mmol) 37%; purity: about 95% by .sup.1H-NMR.

TABLE-US-00006 Ex. Reactants Product Yield TL2 [00413] [00414] 19% [00415] TL3 [00416] [00417] 15% [00418] TL4 [00419] [00420] 21% [00421] TL5 [00422] [00423] 20% [00424]

2) Synthesis of the Hexadentate Ligands HL

Example HL1

[0152] ##STR00425##

[0153] To a mixture of 66.3 g (100 mmol) of 2,2′-[5″-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)[1,1′:2′,1″:3″,1′″:2′″,1″″-quinquephenyl]-4,4″″-diyl]bispyridine [1989597-72-9], 37.4 g (100 mmol) of S50, 63.7 g (300 mmol) of tripotassium phosphate, 300 ml of toluene, 150 ml of dioxane and 300 ml of water are added, with good stirring, 1.64 g (4 mmol) of SPhos and then 449 mg (2 mmol) of palladium(II) acetate, and then the mixture is heated under reflux for 24 h. After cooling, the organic phase is removed and washed twice with 300 ml each time of water and once with 300 ml of saturated sodium chloride solution, and dried over magnesium sulfate. The desiccant is filtered off, the filtrate is concentrated to dryness under reduced pressure and the glassy crude product is recrystallized at boiling from acetonitrile (˜150 ml) and then for a second time from acetonitrile/ethyl acetate. Yield: 58.1 g (70 mmol), 70%; purity: about 95% by .sup.1H-NMR.

TABLE-US-00007 Ex. Reactants Product Yield HL2 [00426] [00427] 73% HL3 [00428] [00429] 70% HL4 [00430] [00431] 76% HL5 [00432] [00433] 74% HL6 [00434] [00435] 61% HL7 [00436] [00437] 73% HL8 [00438] [00439] 70% HL9 [00440] [00441] 59% HL10 [00442] [00443] 69%

C Synthesis of the Metal Complexes

1) Synthesis of the Homoleptic Iridium Complexes of the IrL.SUB.3 .Type: Homoleptic Tris-Facial Iridium Complexes

Variant A: Tris(Acetylacetonato)Iridium(III) as Iridium Reactant

[0154] A mixture of 10 mmol of tris(2,2,6,6-tetramethyl-3,5-heptanedionato)iridium (III) [99581-86-9] and 60 mmol of ligand L is sealed into a 50 ml glass ampoule by melting under reduced pressure (10.sup.−5 mbar). The ampoule is heated at the temperature specified for the time specified, in the course of which the molten mixture is stirred with the aid of a magnetic stirrer. A high-boiling alkane, e.g. octadecane, is added if appropriate. After cooling (CAUTION: the ampoules are usually under pressure!), the ampoule is opened, and the sinter cake is stirred and mechanically digested with 100 g of glass beads (diameter 3 mm) in 100 ml of the suspension medium specified. The fine suspension is decanted off from the glass beads, the solids are filtered off with suction and dried under reduced pressure. The solids are dissolved in dichloromethane, sorbed onto Isolute SI (from Biotage) and then subjected to column chromatography on silica gel with dichloromethane. Further purification is effected by repeated hot extraction. The solids are placed atop a 5 cm alumina bed (alumina, basic activity level 1) and then extracted with the extractant specified (amount initially charged about 500 ml). The solids from the suspensions thus obtained are filtered off with suction, washed once with about 50 ml of methanol and dried. After drying, the purity of the metal complex is determined by means of NMR and/or HPLC. If the purity is below 99.5%, the hot extraction step is repeated. Once the purity of 99.5%-99.9% has been attained, the metal complex is heat-treated or sublimed. The heat treatment is effected under high vacuum (p about 10.sup.−6 mbar) within the temperature range of 200-350° C. The sublimation is effected under high vacuum (p about 10.sup.−6 mbar) within the temperature range of about 320 to about 450° C., the sublimation preferably being conducted in the form of a fractional sublimation.

TABLE-US-00008 Reaction temp./ reaction time Suspension Ligand medium Ex. L Ir complex Extractant Yield Ir(L1).sub.3 [00444] [00445] 240° C. 30 h acetonitrile DCM/acetonitrile 2/1 (vv) 16% Ir(L2).sub.3 [00446] [00447] 230° C. 40 h acetonitrile DCM/acetonitrile 3/1 (vv) 24% Ir(L3).sub.3 [00448] [00449] 240° C. 30 h ethyl acetate DCM/acetonitrile 2/1 (vv) 19% Ir(L4).sub.3 [00450] [00451] 230° C. 20 h acetonitrile DCM/acetonitrile 3/1 (vv) 12%

2) Synthesis of the Heteroleptic Iridium Complexes of the L′.SUB.2.IrL Type

[0155] To a well-stirred suspension of 5 mmol of the specified iridium reactant of the [L.sub.2IrCl].sub.2 type, 10 mmol of ligand L and 50 g of glass beads (diameter 3 mm) in 200 ml of 1,2-dichloromethane are added 60 mmol of triethylamine and then 10 mmol of silver trifluoromethanesulfonate, and the mixture is stirred at 90° 0 for 24 h. While the mixture is still warm, the precipitated silver chloride is filtered off using a silica gel bed in the form of a slurry, which is washed through with a little 1,2-dichloroethane, and the filtrate is concentrated to dryness. Subsequently, the crude product is chromatographed on silica gel (eluent: dichloromethane, toluene, ethyl acetate, acetone, THF, cyclohexane, n-heptane, etc.; and/or mixtures thereof). Further purification is effected as described under 1) by repeated hot extraction and heat treatment or fractional sublimation under high vacuum.

TABLE-US-00009 Ligand Iridium reactant Ex. L Ir complex Yield Ir1 [00452] [00453] 32% [00454] Ir2 [00455] [00456] 29% [00457] Ir3 [00458] [00459] 34% [00460] Ir4 [00461] [00462] 30% [00463] Ir5 [00464] [00465] 26% [00466] Ir6 [00467] [00468] 31% [00469] Ir7 [00470] [00471] 35% [00472] Ir8 [00473] [00474] 38% [00475]

3) Synthesis of the Pt Complexes with Tetradentate Ligands of the Pt(TL) Type

[0156] A mixture of 10 mmol of ligand L, 10 mmol of K.sub.2PtCl.sub.4, 400 mmol of lithium acetate (anhydrous) and 200 ml of glacial acetic acid is heated to 150° C. in a stirred autoclave for 60 h. After cooling and adding 200 ml of water, the precipitated solids are filtered off, and these are twice extracted by stirring in 200 ml of hot ethanol/water (1:1 vv), filtered off with suction and washed through three times with 50 ml each time of ethanol. Subsequently, the crude product is chromatographed on silica gel (eluent: dichloromethane, toluene, ethyl acetate, acetone, THF, cyclohexane, n-heptane, etc.; and/or mixtures thereof). Further purification is effected as described under 1) by repeated hot extraction and heat treatment or fractional sublimation under high vacuum.

TABLE-US-00010 Ex. Reactant Product Yield Pt(TL1) TL1 [00476] 40% Pt(TL2) TL2 [00477] 36% Pt(TL3) TL3 [00478] 39% Pt(TL4) TL4 [00479] 41% Pt(TL5) TL5 [00480] 35%

4) Synthesis of the Iridium Complexes with Hexadentate Ligands of the Ir(HL) Type

[0157] A mixture of 10 mmol of ligand HL, 4.90 g (10 mmol) of trisacetylacetonatoiridium(III) [15635-87-7] and 120 g of hydroquinone [123-31-9] is initially charged in a 1000 ml two-neck round-bottom flask with a glass-sheathed magnetic bar. The flask is provided with a water separator (for media of lower density than water) and an air condenser with argon blanketing. The flask is placed in a metal heating bath. The apparatus is purged with argon from the top via the argon blanketing system for 15 min, allowing the argon to flow out of the side neck of the two-neck flask. Through the side neck of the two-neck flask, a glass-sheathed Pt-100 thermocouple is introduced into the flask and the end is positioned just above the magnetic stirrer bar. Then the apparatus is thermally insulated with several loose windings of domestic aluminum foil, the insulation being run up to the middle of the riser tube of the water separator. Then the apparatus is heated rapidly with a heated laboratory stirrer system to 250-255° C., measured with the Pt-100 temperature sensor which dips into the molten stirred reaction mixture. Over the next 2 h, the reaction mixture is kept at 250-255° C., in the course of which a small amount of condensate is distilled off and collects in the water separator. After 2 h, the mixture is allowed to cool down to 190° C., the heating bath is removed and then 100 ml of ethylene glycol are added dropwise. After cooling to 100° C., 400 ml of methanol are slowly added dropwise. The yellow suspension thus obtained is filtered through a double-ended frit, and the yellow solids are washed three times with 50 ml of methanol and then dried under reduced pressure. Crude yield: quantitative. The solids thus obtained are dissolved in 200-500 ml of dichloromethane and filtered through about 1 kg of silica gel in the form of a dichloromethane slurry (column diameter about 18 cm) with exclusion of air in the dark, leaving dark-colored components at the start. The core fraction is cut out and concentrated on a rotary evaporator, with simultaneous continuous dropwise addition of MeOH until crystallization. After filtration with suction, washing with a little MeOH and drying under reduced pressure, the orange product is purified further by continuous hot extraction four times with dichloromethane/isopropanol 1:1 (vv) and then hot extraction four times with dichloromethane/acetonitrile (amount initially charged in each case about 200 ml, extraction thimble: standard Soxhlet thimbles made of cellulose from Whatman) with careful exclusion of air and light. The loss into the mother liquor can be adjusted via the ratio of dichloromethane (low boilers and good dissolvers):isopropanol or acetonitrile (high boilers and poor dissolvers). It should typically be 3-6% by weight of the amount used. Hot extraction can also be accomplished using other solvents such as toluene, xylene, ethyl acetate, butyl acetate, etc. Finally, the product is subjected to fractional sublimation or heat treatment under high vacuum at p˜10.sup.−6 mbar and T˜350-430° C. Purity typically >99.7%.

TABLE-US-00011 Ex. Reactant Product Yield Ir(HL1) HL1 [00481] 55% Ir(HL2) HL2 [00482] 57% Ir(HL3) HL3 [00483] 48% Ir(HL4) HL4 [00484] 56% Ir(HL5) HL5 [00485] 53% Ir(HL6) HL6 [00486] 41% Ir(HL7) HL7 [00487] 47% Ir(HL8) HL8 [00488] 57% Ir(HL9) HL9 [00489] 40% Ir(HL10) HL10 [00490] 45%

Example: Production of the OLEDs

1) Vacuum-Processed Devices

[0158] OLEDs of the invention and OLEDs according to the prior art are produced by a general method according to WO 2004/058911, which is adapted to the circumstances described here (variation in layer thickness, materials used). In the examples which follow, the results for various OLEDs are presented. Cleaned glass plates (cleaning in Miele laboratory glass washer, Merck Extran detergent) coated with structured ITO (indium tin oxide) of thickness 50 nm are pretreated with UV ozone for 25 minutes (PR-100 UV ozone generator from UVP) and, within 30 min, for improved processing, coated with 20 nm of PEDOT:PSS (poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate), purchased as CLEVIOS™ P VP AI 4083 from Heraeus Precious Metals GmbH Deutschland, spun on from aqueous solution) and then baked at 180° C. for 10 min. These coated glass plates form the substrates to which the OLEDs are applied.

[0159] The OLEDs basically have the following layer structure: substrate/hole injection layer 1 (HIL1) consisting of HTM1 doped with 5% NDP-9 (commercially available from Novaled), 20 nm/hole transport layer 1 (HTL1) consisting of HTM1, 220 nm for green/yellow devices, 110 nm for red devices/hole transport layer 2 (HTL2)/emission layer (EML)/hole blocker layer (HBL)/electron transport layer (ETL)/optional electron injection layer (EIL) and finally a cathode. The cathode is formed by an aluminum layer of thickness 100 nm.

[0160] First of all, vacuum-processed OLEDs are described. For this purpose, all the materials are applied by thermal vapor deposition in a vacuum chamber. In this case, the emission layer always consists of at least one matrix material (host material) and an emitting dopant (emitter) which is added to the matrix material(s) in a particular proportion by volume by co-evaporation. Details given in such a form as M1:M2:Ir(L1) (55%:35%:10%) mean here that the material M1 is present in the layer in a proportion by volume of 55%, M2 in a proportion by volume of 35% and Ir(L1) in a proportion by volume of 10%. Analogously, the electron transport layer may also consist of a mixture of two materials. The exact structure of the OLEDs can be found in table 2. The materials used for production of the OLEDs are shown in table 4.

[0161] The OLEDs are characterized in a standard manner. For this purpose, the electroluminescence spectra, the current efficiency (measured in cd/A), the power efficiency (measured in Im/W) and the external quantum efficiency (EQE, measured in percent) as a function of luminance, calculated from current-voltage-luminance characteristics (IUL characteristics) assuming Lambertian emission characteristics, and also the lifetime are determined. Electroluminescence spectra are determined at a luminance of 1000 cd/m.sup.2, and these are used to calculate the CIE 1931 x and y color coordinates. The lifetime LT50 is defined as the time after which the luminance in operation has dropped to 50% of the starting luminance with a starting brightness of 1000 cd/m.sup.2.

[0162] The OLEDs can initially also be operated at different starting luminances. The values for the lifetime can then be converted to a figure for other starting luminances with the aid of conversion formulae known to those skilled in the art.

Use of Compounds of the Invention as Emitter Materials in Phosphorescent OLEDs

[0163] One use of the compounds of the invention is as phosphorescent emitter materials in the emission layer in OLEDs. The results for the OLEDs are collated in table 2.

TABLE-US-00012 TABLE 1 Structure of the OLEDs HTL2 EML HBL ETL Ex. thickness thickness thickness Thickness D1 HTM2 M1:M9:Ir(L1).sub.3 ETM1 ETM1:ETM2 10 nm (55%:30%:15%) 10 nm (50%:50%) 30 nm 30 nm D2 HTM2 M1:M9:Ir(L2).sub.3 ETM1 ETM1:ETM2 10 nm (55%:30%:15%) 10 nm (50%:50%) 30 nm 30 nm D3 HTM2 M1:M2:Ir(L3).sub.3 ETM1 ETM1:ETM2 10 nm (55%:30%:15%) 10 nm (50%:50%) 30 nm 30 nm D4 HTM2 M1:M2:Ir(L4).sub.3 ETM1 ETM1:ETM2 10 nm (55%:30%:15%) 10 nm (50%:50%) 30 nm 30 nm D5 HTM2 M1:M9:Ir1 ETM1 ETM1:ETM2 10 nm (55%:35%:10%) 10 nm (50%:50%) 30 nm 30 nm D6 HTM2 M1:M9:Ir2 ETM1 ETM1:ETM2 10 nm (55%:35%:10%) 10 nm (50%:50%) 30 nm 30 nm D7 HTM2 M1:M2:Ir3 ETM1 ETM1:ETM2 10 nm (55%:35%:10%) 10 nm (50%:50%) 30 nm 30 nm D8 HTM2 M1:M2:Ir4 ETM1 ETM1:ETM2 10 nm (50%:40%:10%) 10 nm (50%:50%) 30 nm 30 nm D9 HTM2 M1:M7:Pt(TL1) ETM1 ETM1:ETM2 10 nm (40%:40%:20%) 10 nm (50%:50%) 30 nm 30 nm D10 HTM2 M1:M9:Pt(TL2) ETM1 ETM1:ETM2 10 nm (50%:40%:10%) 10 nm (50%:50%) 30 nm 30 nm D11 HTM2 M6:Pt(TL3) ETM1 ETM1:ETM2 10 nm (90%:10%) 10 nm (50%:50%) 30 nm 30 nm D12 HTM2 M1:M2:Pt(TL4) ETM1 ETM1:ETM2 10 nm (50%:40%:10%) 10 nm (50%:50%) 30 nm 30 nm D13 HTM2 M1:M9:Ir(HL1) ETM1 ETM1:ETM2 10 nm (50%:40%:10%) 10 nm (50%:50%) 30 nm 30 nm D14 HTM2 M1:M7:Ir(HL2) ETM1 ETM1:ETM2 10 nm (40%:40%:20%) 10 nm (50%:50%) 30 nm 30 nm D15 HTM2 M1:M9:Ir(HL4) ETM1 ETM1:ETM2 10 nm (50%:40%:10%) 10 nm (50%:50%) 30 nm 30 nm D16 HTM2 M1:M9:Ir(HL5) ETM1 ETM1:ETM2 10 nm (50%:40%:10%) 10 nm (50%:50%) 30 nm 30 nm D17 HTM2 M1:M8:Ir(HL8) ETM1 ETM1:ETM2 10 nm (60%:30%:10%) 10 nm (50%:50%) 30 nm 30 nm D18 HTM2 M6:Ir(HL10) — ETM1:ETM2 10 nm (90%:10%) (50%:50%) 30 nm 30 nm

TABLE-US-00013 TABLE 2 Results for the vacuum-processed OLEDs EQE (%) Voltage (V) CIE x/y LT50 (h) Ex. 1000 cd/m.sup.2 1000 cd/m.sup.2 1000 cd/m.sup.2 1000 cd/m.sup.2 D1 16.3 3.3 0.19/0.41  10000 D2 17.0 3.2 0.22/0.43  15000 D3 20.0 3.2 0.29/0.61 200000 D4 20.5 3.3 0.33/0.62 220000 D5 17.0 3.3 0.24/0.46  20000 D6 15.8 3.3 0.20/0.42  15000 D7 20.1 3.3 0.30/0.62 230000 D8 20.6 3.1 0.33/0.63 210000 D9 20.2 3.6 0.31/0.62 200000 D10 19.9 3.3 0.31/0.61 190000 D11 18.0 3.2 0.65/0.34 300000 D12 20.4 3.3 0.37/0.59 250000 D13 20.1 3.3 0.38/0.58 260000 D14 19.5 3.2 0.34/0.61 220000 D15 18.8 3.3 0.42/0.57 210000 D16 18.4 3.4 0.41/0.56 260000 D17 17.2 3.6 0.29/0.62 — D18 16.7 3.2 0.66/0.34 300000

Solution-Processed Devices

A: From Soluble Functional Materials of Low Molecular Weight

[0164] The iridium complexes of the invention may also be processed from solution and lead therein to OLEDs which are much simpler in terms of process technology compared to the vacuum-processed OLEDs, but nevertheless have good properties. 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 WO 2004/037887). The structure is composed of substrate/ITO/hole injection layer (60 nm)/interlayer (20 nm)/emission layer (60 nm)/hole blocker layer (10 nm)/electron transport layer (40 nm)/cathode. For this purpose, substrates from Technoprint (soda-lime glass) are used, to which the ITO structure (indium tin oxide, a transparent conductive anode) is applied. The substrates are cleaned in a cleanroom with DI water and a detergent (Deconex 15 PF) and then activated by a UV/ozone plasma treatment. Thereafter, likewise in a cleanroom, a 20 nm hole injection layer is applied by spin-coating. The required spin rate depends on the degree of dilution and the specific spin-coater geometry. In order to remove residual water from the layer, the substrates are baked on a hotplate at 200° C. for 30 minutes. The interlayer used serves for hole transport, in this case, HL-X from Merck is used. The interlayer may alternatively also be replaced by one or more layers which merely have to fulfill the condition of not being leached off again by the subsequent processing step of EML deposition from solution. For production of the emission layer, the triplet emitters of the invention are dissolved together with the matrix materials in toluene or chlorobenzene. The typical solids content of such solutions is between 16 and 25 g/l when, as here, the layer thickness of 60 nm which is typical of a device is to be achieved by means of spin-coating. The solution-processed devices of type 1 contain an emission layer composed of M4:M5:IrL (20%:58%:22%), and those of type 2 contain an emission layer composed of M4:M5:IrLa:IrLb (30%:34%:29%:7%); in other words, they contain two different Ir complexes. The percent figures in the case of materials processed from solution mean % by weight. The emission layer is spun on in an inert gas atmosphere, argon in the present case, and baked at 160° C. for 10 min. Vapor-deposited above the latter are the hole blocker layer (10 nm ETM1) and the electron transport layer (40 nm ETM1 (50%)/ETM2 (50%)) (vapor deposition systems from Lesker or the like, typical vapor deposition pressure 5×10.sup.−6 mbar). Finally, a cathode of aluminum (100 nm) (high-purity metal from Aldrich) is applied by vapor deposition. In order to protect the device from air and air humidity, the device is finally encapsulated and then characterized. The OLED examples cited have not yet been optimized. Table 3 summarizes the data obtained. The lifetime LT50 is defined as the time after which the luminance in operation drops to 50% of the starting luminance with a starting brightness of 1000 cd/m.sup.2.

TABLE-US-00014 TABLE 3 Results with materials processed from solution Voltage EQE (%) (V) LT50 (h) Emitter 1000 1000 1000 Ex. Device cd/m.sup.2 cd/m.sup.2 CIE x/y cd/m.sup.2 Sol-D1 Ir5 16.6 4.3 0.40/0.56 170000 Type 1 Sol-D2 Ir6 17.3 4.5 0.46/0.52 210000 Type 1 Sol-D3 Ir7 19.0 4.5 0.40/0.58 200000 Type 1 Sol-D4 Ir5 18.1 4.2 0.66/0.34 260000 Ir8 Type 2 Sol-D5 Pt(TLS) 17.8 4.6 0.43/0.55 290000 Type 1 Sol-D6 Ir(HL3) 16.8 4.5 0.33/0.61 220000 Type 1 Sol-D7 Ir(HL6) 17.4 4.5 0.43/0.55 250000 Type 1 Sol-D8 Ir(HL6) 16.8 4.2 0.66/0.34 250000 Ir(HL7) Type 2 Sol-D9 Ir(HL9) 17.8 4.5 0.36/0.60 220000 Type 1

TABLE-US-00015 TABLE 4 Structural formulae of the materials used [00491] [00492] [00493] [00494] [00495] [00496] [00497] [00498] [00499] [00500] [00501] [00502]

Comparison with the Prior Art

[0165] The complexes depicted below that have a similar ligand to the complexes of the invention, where the ligands here coordinate via the five-membered ring and a six-membered ring rather than via two six-membered rings in accordance with the invention, are known from US 2012/0153816.

##STR00503##

[0166] For the two complexes, CIE color coordinates of CIE x/y 0.19/0.28 are reported. The complexes that coordinate to the iridium via one five-membered and one six-membered ring thus show blue emission, whereas the complexes of the invention show green, yellow or red emission.